U.S. patent application number 12/205578 was filed with the patent office on 2009-03-05 for vapor based combinatorial processing.
Invention is credited to Tony P. Chiang, Chi-I Lng, Sunil Shanker.
Application Number | 20090061646 12/205578 |
Document ID | / |
Family ID | 40407928 |
Filed Date | 2009-03-05 |
United States Patent
Application |
20090061646 |
Kind Code |
A1 |
Chiang; Tony P. ; et
al. |
March 5, 2009 |
VAPOR BASED COMBINATORIAL PROCESSING
Abstract
A combinatorial processing chamber and method are provided. In
the method a fluid volume flows over a surface of a substrate with
differing portions of the fluid volume having different constituent
components to concurrently expose segregated regions of the
substrate to a mixture of the constituent components that differ
from constituent components to which adjacent regions are exposed.
Differently processed segregated regions are generated through the
multiple flowings.
Inventors: |
Chiang; Tony P.; (San Jose,
CA) ; Shanker; Sunil; (San Jose, CA) ; Lng;
Chi-I; (San Jose, CA) |
Correspondence
Address: |
MARTINE PENILLA GENCARELLA, LLP
710 LAKEWAY DRIVE, SUITE 200
SUNNYVALE
CA
94085
US
|
Family ID: |
40407928 |
Appl. No.: |
12/205578 |
Filed: |
September 5, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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12013729 |
Jan 14, 2008 |
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12205578 |
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60970199 |
Sep 5, 2007 |
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Current U.S.
Class: |
438/763 ;
118/715; 257/E21.24 |
Current CPC
Class: |
C23C 16/45548 20130101;
C23C 16/45574 20130101; C23C 16/45544 20130101 |
Class at
Publication: |
438/763 ;
118/715; 257/E21.24 |
International
Class: |
H01L 21/31 20060101
H01L021/31; H01L 21/30 20060101 H01L021/30 |
Claims
1. A device for distributing fluids in a semiconductor processing
chamber, the device comprising: a baffle plate having first and
second opposed sides with a plurality of throughways extending
between the first and the second opposed sides; and a faceplate
coupled to the baffle plate, the faceplate segmented into sectors
of injection ports extending therethrough, the segmented sectors
defined through a fluid separation mechanism extending radially
outwardly from an axis of the faceplate, the fluid separation
mechanism facilitating sector separation of fluids propagating
through the injection ports, wherein the baffle plate and the
faceplate define a plenum when coupled together.
2. The device of claim 1, wherein a number of the sectors
corresponds to a number of the throughways.
3. The device as recited in claim 1 wherein the fluid separation
mechanism includes a body extending from a surface of the
faceplate, the body configured to maintain separation of fluids
propagating through adjacent sectors.
4. The device as recited in claim 3 wherein the body extends one of
away from both the surface of the faceplate and a surface of the
baffle plate or away from the surface of the faceplate and toward a
surface of the baffle plate.
5. The device as recited in claim 1 wherein the injection ports
include first and second fluid passages, with the second fluid
passage being disposed within the first fluid passage.
6. The device as recited in claim 1 wherein the fluid separation
mechanism is a set of injection ports disposed between adjacent
sectors.
7. The device as recited in claim 6 wherein the injection ports
include first and second fluid passages, with the first fluid
passage having a longitudinal axis and second fluid passage being
disposed within the first fluid passage and extending along the
longitudinal axis.
8. The device as recited in claim 6, wherein a distribution density
of the set of injection ports disposed between adjacent sectors is
different than a distribution density of the injection ports of the
sectors.
9. The device as recited in claim 6, wherein a diameter of the
injection ports disposed between adjacent sectors is different than
a diameter of the injection ports of the sectors.
10. A showerhead for distributing fluids with a processing chamber,
comprising: means for independently receiving a plurality of fluid
flows; and means for distributing the received plurality of fluid
flows through segmented sectors, the means for distributing coupled
to the means for independently receiving the plurality of fluid
flows, the means for distributing including means for maintaining
separation of the plurality of fluid flows propagating through the
means for distributing the received plurality of fluid flows
according to the segmented sectors.
11. The showerhead of claim 10, wherein a number of the segmented
sectors corresponds to a number of the plurality of fluid
flows.
12. The showerhead of claim 10, wherein coupling of the means for
independently receiving and the means for distributing define a
plenum.
13. The showerhead of claim 10, wherein the means for maintaining
separation is selected from a group consisting of extending from a
surface of the means for distributing, extending away from a
surface of the means for distributing and away from a surface of
the means for independently receiving, and extending away from a
surface of the means for distributing and towards a surface of the
means for independently receiving.
14. The showerhead of claim 10, wherein the means for maintaining
separation includes means for propagating a fluid between segmented
sectors.
15. The showerhead of claim 10, wherein the means for distributing
includes a first means for fluid passage defined within a second
means for fluid passage and wherein the first means and the second
means share a longitudinal axis.
16. The showerhead of claim 10, wherein the showerhead is
incorporated into a combinatorial processing system configured to
deposit material onto isolated regions of a substrate, the isolated
regions corresponding to the segmented sectors.
17. A method of processing a substrate, comprising: flowing
segregated portions of a fluid volume having different constituent
components to concurrently expose corresponding segregated sectors
of the substrate to a mixture of the constituent components that
differ from constituent components to which an adjacent segregated
sector is exposed; and maintaining separation of the segregated
portions through a separation fluid flowing between adjacent
segregated sectors.
18. The method of claim 17, wherein the separation fluid flows
through injection ports having a first diameter and the segregated
portions flow through injection ports having a second diameter.
19. The method of claim 17, further comprising: depositing layers
on the corresponding segregated sectors wherein at least two of the
layers have different compositions.
20. The method of claim 19, wherein each of the different
compositions of the at least two of the layers is substantially
uniform over the corresponding segregated sectors.
Description
CLAIM OF PRIORITY
[0001] This application claims the benefit of U.S. Application Ser.
No. 60/970,199 filed Sep. 5, 2007, and is a continuation of U.S.
application Ser. No. 12/013,729 filed on Jan. 14, 2008, both of
which are incorporated by reference in their entirety for all
purposes.
BACKGROUND
[0002] This invention relates to semiconductor processing. More
particularly, this invention relates to a processing system and a
method of site-isolated vapor based processing to facilitate
combinatorial film deposition and integration on a substrate.
[0003] Chemical Vapor Deposition (CVD) is a vapor based deposition
process commonly used in semiconductor manufacturing including but
not limited to the formation of dielectric layers, conductive
layers, semiconducting layers, liners, barriers, adhesion layers,
seed layers, stress layers, and fill layers. CVD is typically a
thermally driven process whereby the precursor flux(es) are
pre-mixed and coincident to the substrate surface to be deposited
upon. CVD requires control of the substrate temperature and the
incoming precursor flux(es) to achieve desired film materials
properties and thickness uniformity. Derivatives of CVD based
processes include but are not limited to Plasma Enhanced Chemical
Vapor Deposition (PECVD), High-Density Plasma Chemical Vapor
Deposition (HDP-CVD), Sub-Atmospheric Chemical Vapor Deposition
(SACVD), laser assisted/induced CVD, and ion assisted/induced
CVD.
[0004] As device geometries shrink and associated film thickness
decrease, there is an increasing need for improved control of the
deposited layers. A variant of CVD that enables superior step
coverage, materials property, and film thickness control is a
sequential deposition technique known as Atomic Layer Deposition
(ALD). ALD is a multi-step, self-limiting process that includes the
use of at least two precursors or reagents. Generally, a first
precursor (or reagent) is introduced into a processing chamber
containing a substrate and adsorbs on the surface of the substrate.
Excess first precursor is purged and/or pumped away. A second
precursor (or reagent) is then introduced into the chamber and
reacts with the initially adsorbed layer to form a deposited layer
via a deposition reaction. The deposition reaction is self-limiting
in that the reaction terminates once the initially adsorbed layer
is consumed by the second precursor. Excess second precursor is
purged and/or pumped away. The aforementioned steps constitute one
deposition or ALD "cycle." The process is repeated to form the next
layer, with the number of cycles determining the total deposited
film thickness. Different sets of precursors can also be chosen to
form nano-composites comprised of differing materials compositions.
Derivatives of ALD include but are not limited to Plasma Enhanced
Atomic Layer Deposition (PEALD), radical assisted/enhanced ALD,
laser assisted/induced ALD, and ion assisted/induced ALD.
[0005] Presently, conventional vapor-based processes such as CVD
and ALD are designed to process uniformly across a full wafer. In
addition, these CVD and ALD processes need to be integrated into
process/device flows. Uniform processing results in fewer data per
substrate, longer times to accumulate a wide variety of data and
higher costs associated with obtaining such data.
[0006] As part of the discovery, optimization and qualification
process for new ALD and CVD films, the invention enables one to
test i) more than one material, ii) more than one processing
condition, iii) more than one sequence of processing conditions,
and iv) more than one process sequence integration flow on a single
monolithic substrate without the need of consuming the equivalent
number of monolithic substrates per material(s), processing
condition(s), sequence(s) of processing conditions, sequence(s) of
processes, and combinations thereof. This can greatly improve both
the speed and reduce the costs associated with the discovery,
implementation, optimization, and qualification of new CVD and ALD
based material(s), process(es), and process integration sequence(s)
required for manufacturing. The invention provides systems,
components, and method for processing substrates in a combinatorial
manner through the variation of constituent parts of a fluid
volume.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The present invention will be readily understood by the
following detailed description in conjunction with the accompanying
drawings. Like reference numerals designate like structural
elements.
[0008] FIG. 1 is a detailed cross-sectional view of a system in
accordance with one embodiment of the present invention;
[0009] FIG. 2 is a simplified schematic view showing the flow of
processing fluids in the system shown in FIG. 1;
[0010] FIG. 3 is a bottom-up exploded perspective view of a
showerhead assembly employed in the semiconductor processing system
shown in FIG. 11 in accordance with a first embodiment;
[0011] FIG. 4 is a top-down exploded perspective view of a
showerhead shown in FIG. 3, in accordance with the present
invention;
[0012] FIG. 5 is a top-down view of a manifold body of the
showerhead shown in FIGS. 3 and 4;
[0013] FIG. 6 is a plan view of a fluid supply system of a
processing chamber shown in FIG. 1, in accordance with one
embodiment of the present invention;
[0014] FIG. 7 is a graphical representation of the operation of the
fluid supply system shown in FIG. 6 and the resulting distribution
of processing fluids exiting the showerhead shown in FIGS. 3, 4 and
5;
[0015] FIG. 5A is a top down plan view showing movement of
processing fluids over a surface of a substrate disposed in a
processing region, shown in FIG. 1, in accordance with the present
invention;
[0016] FIG. 8B is a simplified schematic diagram illustrating the
flow vectors for the axi-symmetric segmented gas flow enabling
species isolation to define segregated sectors of the wafer surface
in accordance with one embodiment of the invention;
[0017] FIG. 9 is a detailed cross-sectional view of the system
shown in FIG. 1 in accordance with a first alternate embodiment of
the present invention;
[0018] FIG. 10 is a detailed cross-sectional view of the system
shown in FIG. 1 in accordance with a second alternate embodiment of
the present invention;
[0019] FIG. 11A is a plan view of a fluid supply system of the
processing chamber shown in FIG. 1, in accordance with an alternate
embodiment of the present invention;
[0020] FIG. 11B is a graphical representation of the operation of
the fluid supply system shown in FIG. 11A as it relates to the
substrate in FIGS. 8A and 8B.
[0021] FIG. 12 is a cross-sectional view of the manifold body shown
in FIG. 4 in accordance with an alternate embodiment of the present
invention;
[0022] FIG. 13 is a top-down view of a manifold body shown in FIGS.
3 and 4 in accordance with an alternate embodiment of the present
invention;
[0023] FIGS. 13-1, 13-2, 13-3, and 13-4 illustrate exemplary
embodiments of the showerhead of FIG. 13 in accordance with one
embodiment of the invention.
[0024] FIG. 14 is a detailed view of injection ports made in the
manifold body shown in FIGS. 3, 4, 5 and 14 in accordance with an
alternate embodiment of the present invention;
[0025] FIG. 15A shows a simplified cross sectional view of a
substrate that has structures defined from combinatorial processing
sequences for screening purposes in accordance with one embodiment
of the invention; and
[0026] FIG. 15B is a top-down view of a substrate having material
formed thereon in accordance with an alternate embodiment of the
present invention.
[0027] FIG. 16 is a top-down view of a substrate showing
segmentation of regions thereof in accordance with an embodiment of
the present invention;
[0028] FIG. 17 is a simplified plan view of a cluster tool in which
any of the processing systems shown in FIGS. 1, 9 and 10 may be
included;
[0029] FIG. 18 is a bottom-up view of a fluid control mechanism in
accordance with yet another embodiment of the present
invention;
[0030] FIG. 19 is a simplified plan view of a system for depositing
material on a substrate including the fluid control mechanism shown
in FIG. 18;
[0031] FIG. 20 is a top down view of the system shown in FIG. 19
with the fluid control mechanism removed;
[0032] FIGS. 21-23 show the application of the screening process to
a process sequence for a gate stack configuration in accordance
with one embodiment of the invention;
[0033] FIGS. 24-25 show a screening technique for evaluating a
metal-insulator-metal (MIM) structure for a memory device in
accordance with one embodiment of the invention;
DETAILED DESCRIPTION
[0034] The embodiments described herein provide a method and system
for evaluating materials, unit processes, and process integration
sequences to improve semiconductor manufacturing operations. It
will be obvious, however, to one skilled in the art, that the
present invention may be practiced without some or all of these
specific details. In other instances, well known process operations
have not been described in detail in order not to unnecessarily
obscure the present invention.
[0035] The embodiments described herein enable the application of
combinatorial techniques to deposition process sequence integration
in order to arrive at a globally optimal sequence of semiconductor
manufacturing operations by considering interaction effects between
the unit manufacturing operations on multiple regions of a
substrate concurrently, Specifically, multiple process conditions
may be concurrently employed to effect such unit manufacturing
operations, as well as material characteristics of components
utilized within the unit manufacturing operations, thereby
minimizing the time required to conduct the multiple operations. A
global optimum sequence order can also be derived and as part of
this technique, the unit processes, unit process parameters and
materials used in the unit process operations of the optimum
sequence order are also considered.
[0036] The embodiments are capable of analyzing a portion or
sub-set of the overall deposition process sequence used to
manufacture a semiconductor device. The process sequence may be one
used in the manufacture of integrated circuits (IC) semiconductor
devices, flat panel displays, optoelectronics devices, data storage
devices, magneto electronic devices, magneto optic devices,
packaged devices, and the like. Once the subset of the process
sequence is identified for analysis, combinatorial process sequence
integration testing is performed to optimize the materials, unit
processes and process sequence for that portion of the overall
process identified. During the processing of some embodiments
described herein, the deposition may be used to form structures or
modify structures already formed on the substrate, which structures
are equivalent to the structures formed during manufacturing of
substrates for production. For example, structures on semiconductor
substrates may include, but would not be limited to, trenches,
vias, interconnect lines, capping layers, masking layers, diodes,
memory elements, gate stacks, transistors, or any other series of
layers or unit processes that create a structure found on
semiconductor chips. The material, unit process and process
sequence variations may also be used to create layers and/or unique
material interfaces without creating all or part of an intended
structure, which allows more basic research into properties of the
resulting materials as opposed to the structures or devices created
through the process steps. While the combinatorial processing
varies certain materials, unit processes, or process sequences, the
composition or thickness of the layers or structures or the action
of the unit process is preferably substantially uniform within each
region, but can vary from region to region per the combinatorial
experimentation.
[0037] The result is a series of regions on the substrate that
contain structures or results of unit process sequences that have
been uniformly applied within that region and, as applicable,
across different regions through the creation of an array of
differently processed regions due to the design of experiment. This
process uniformity allows comparison of the properties within and
across the different regions such that the variations in test
results are due to the varied parameter (e.g., materials, unit
processes, unit process parameters, or process sequences) and not
the lack of process uniformity. However, non-uniform processing of
regions can also be used for certain experiments of types of
screening. Namely, gradient processing or regional processing
having non-uniformity outside of manufacturing specifications may
be used in certain situations.
[0038] Combinatorial processing is generally most effective when
used in a screening protocol that starts with relatively simple
screening, sometimes called primary screening, and moves to more
complex screening involving structures and/or electrical results,
sometimes called secondary screening, and then moves to analysis of
the portion of the process sequence in its entirety, sometimes
called tertiary screening. The names for the screening levels and
the type of processing and analysis are arbitrary and depend more
on the specific experimentation being conducted. Thus, the
descriptions above are not meant to be limiting in any fashion. As
the screening levels progress, materials and process variations are
eliminated, and information is fed back to prior stages to further
refine the analysis, so that an optimal solution is derived based
upon the initial specification and parameters.
[0039] In ALD, simple examples of conditions that may be varied,
include the precursors, reagents, carrier gases, order of
precursors, concentration of precursors/reagents, duration of
precursor/reagent pulses, purge fluid species, purge fluid
duration, partial pressures, total pressure, flow rates, growth
rate per cycle, incubation period, growth rate as a function of
substrate type, film thickness, film composition, nano-laminates
(e.g., stacking of different ALD film types), precursor source
temperatures, substrate temperatures, temperature for saturative
adsorption, temperature window for ALD, temperature for thermal
decomposition of the precursor(s), plasma power for
plasma/ion/radical based ALD, etc. A primary screen may start with
varying the precursor and purge fluid pulse durations and flows at
increasing substrate temperatures to determine the ALD process
window (a zone characterized by self-limiting deposition with weak
temperature dependence) for a given film type. A secondary screen
may entail stacking two or more such ALD films to vary the
effective dielectric constant of a film stack in a simple MIM
capacitor structure for example. The output of such a screen may be
those candidates which yield the highest effective dielectric
constant at the lowest leakage and remain stable through a high
temperature (e.g. >500.degree. C.) thermal anneal. The system
and methods described below are useful to implement combinatorial
experimentation as described above, and are particularly useful for
ALD and CVD processing.
[0040] Fluid as used in this application refers to liquids, gases,
vapors, i.e., a component that flows, and other types of fluids
used in ALD and CVD processes and their variants and these terms
are used interchangeably throughout this specification. A
constituent component may be a liquid at some point in the system,
the fluid may be converted to a gas, vapor or other such fluid
before entering the processing chamber and being exposed to the
substrate.
[0041] Referring to FIG. 1, a substrate processing system 10 in
accordance with one embodiment of the present invention includes an
enclosure assembly 12 formed from a process-compatible material,
such as aluminum or anodized aluminum. Enclosure assembly 12
includes a housing 14, defining a processing chamber 16 and a
vacuum lid assembly 20 covering an opening to processing chamber
16. Mounted to vacuum lid assembly 20 is a process fluid injection
assembly that delivers reactive and carrier fluids into processing
chamber 16. To that end, the fluid injection assembly includes a
plurality of passageways 30, 31, 32 and 33 and a showerhead 90. The
chamber housing 14, vacuum lid assembly 20, and showerhead 90 may
be maintained within desired temperature ranges in a conventional
manner. It should be appreciated that the Figures provided herein
are illustrative and not necessarily drawn to scale.
[0042] A heater/lift assembly 46 is disposed within processing
chamber 16. Heater/lift assembly 46 includes a support pedestal 48
connected to a support shaft 49. Support pedestal 48 is positioned
between shaft 49 and vacuum lid assembly 20. Support pedestal 48
may be formed from any process-compatible material, including
aluminum nitride and aluminum oxide (Al.sub.2O.sub.3 or alumina)
and is configured to hold a substrate thereon, e.g., support
pedestal 48 may be a vacuum chuck or utilize other conventional
techniques such as an electrostatic chuck (ESC) or physical
clamping mechanisms. Heater lift assembly 46 is adapted to be
controllably moved so as to vary the distance between support
pedestal 48 and the showerhead 90 to control the substrate to
showerhead spacing. A sensor (not shown) provides information
concerning the position of support pedestal 48 within processing
chamber 16. Support pedestal 48 can be used to heat the substrate
through the use of heating elements (not shown) such as resistive
heating elements embedded in the pedestal assembly.
[0043] Referring to both FIGS. 1 and 2 a fluid supply system 69 is
in fluid communication with passageways 30, 31, 32 and 33 through a
sequence of conduits. Flows of processing fluids, from fluid supply
system 69, within processing chamber 16 are provided, in part, by a
pressure control system that may include one or more pumps, such as
turbo pump 64 and roughing pump 66 both of which are in fluid
communication with processing chamber 16 via a butterfly valve 67
and pump channel 68. To that end, a controller 70 regulates the
operations of the various components of system 10. Controller 70
includes a processor 72 in data communication with memory, such as
random access memory 74 and a hard disk drive 76 and is in signal
communication with pump system 64, temperature control system 52,
fluid supply system 69 and various other aspects of the system as
required. System 10 may establish conditions in a region 77 of
processing chamber 16 located proximate to a surface 78 of a
substrate 79 disposed on support pedestal 48 to form desired
material thereon, such as a thin film. To that end, housing 14 is
configured to create a peripheral flow channel 71 that surrounds
support pedestal 48 when placed in a processing position to provide
processing region 77 with the desired dimensions based upon
chemical processes to be achieved by system 10. Pump channel 68 is
situated in housing 14 so that processing region 77 is positioned
between pump channel 68 and showerhead 90.
[0044] The dimensions of peripheral flow channel 71 are defined to
provide a desired conductance of processing fluids therethrough
which provide flows of processing fluids over a surface 78 of
substrate 79 in a substantially uniform manner and in an
axi-symmetric fashion as further described below. To this end, the
conductance through pump channel 68 is chosen to be larger than the
conductance through peripheral flow channel 71. In one embodiment,
the relative conductive of processing fluids through pump channel
68 and peripheral flow channel 71 is, for example, 10:1, wherein
the conductance of pump channel 68 is established to be at least
ten (10) times greater than the conductance of processing fluids
through peripheral flow channel 71. Such a large disparity in the
conductance, which includes other ratios (e.g., 5:1, 8:1, 15:1 and
other higher and lower ratios as applicable to the chamber and
application), serves to facilitate axi-symmetric flow across the
surface 78 of substrate 79 as shown by flows A and B moving through
processing region 77 and subsequently passing substrate 79 and
support pedestal 48 toward pump channel 68.
[0045] Referring to FIGS. 2, 3 and 4, to facilitate the occurrence
of flows A and B, showerhead 90 includes a baffle plate 80 that is
formed to be radially symmetric about a central axis 82, but need
not be. Baffle plate 80 has a plurality of through ports 91, 93, 95
and 97 extending therethrough. Coupled to baffle plate 80 is a
manifold portion 92 having a plurality of injection ports 94
extending through manifold portion 92. Manifold portion 92 is
typically disposed to be radially symmetric about axis 82. Manifold
portion 92 is spaced-apart from surface 86 to define a plenum
chamber 106 therebetween. Manifold portion 92 may be coupled to
baffle plate 80 using any means known in the semiconductor
processing art, including fasteners, welding and the like. Baffle
plate 80 and shower head 90 may be formed from any known material
suitable for the application, including stainless steel, aluminum,
anodized aluminum, nickel, ceramics and the like.
[0046] Referring to FIGS. 3, 4 and 5, extending from manifold
portion 92 is a fluid separation mechanism that includes a body 112
extending from manifold portion 92 toward baffle plate 80. The
distance that body 112 extends from the surface is dependent upon
the specific design parameters and may extend to cover part of the
distance or the entire distance to create sectors within the plenum
106, as discussed more fully below. In one embodiment, body 112 may
extend between the manifold 92 and baffle 80 in two orthogonal
directions to create four regions, referred to as quadrants or
sectors 114, 115, 116 and 117. Although four quadrants are shown,
any number of sectors may be provided by adding additional body
portions 112, depending upon the number of regions one wants to or
can define on substrate 78. A vertex 118 of body 112 is generally
aligned with axis 82. Passageways 30, 31, 32 and 33, shown in FIG.
1, are configured to direct fluid through corresponding ones of
ports 91, 93, 95 and 97. In this manner, ports 91, 93, 95 and 97
are arranged to create flows of processing fluids that are
associated with a corresponding one of quadrants 114-117. The body
112 provides sufficient separation to minimize, if not prevent,
fluids exiting ports 91, 93, 95 and 97 from diffusing between
adjacent quadrants 114-117. In this manner, each of the four ports
91, 93, 95 and 97 directs a flow of processing fluids onto one of
quadrants 114-117 that differs from the quadrants 114-117 into
which the remaining ports 91, 93, 95 and 97 direct flows of
processing fluids.
[0047] FIG. 6 illustrates one possible valving and system
arrangement for the distribution and flowing of a precursor or
reactive reagent to one sector at a time, normally in a serial
manner. Other arrangements, as discussed below, are possible for
serial, semi-parallel or parallel distribution and flowing of vapor
through the showerhead sectors to the corresponding regions on
substrate 79. Referring to both FIGS. 1 and 6, fluid supply system
69 includes two precursor/reagent subsystems 119 and 131 and
various others valves, tubing and features. Reagent subsystem 119
includes a plurality of supplies of carrier or purge fluids or
precursors 120-127 that may include nitrogen (N.sub.2), argon (Ar),
water (H.sub.2O), ammonia (NH.sub.3), oxygen (O.sub.2), hydrogen,
helium, ozone, silane, and any other precursor and/or carrier or
purge fluid(s) (e.g., gases, vapors, etc.) used in ALD or CVD
processing shown generally by additional reagents denoted by X of
supply 127. A precursor distribution system 128 facilitates
selective distribution between supplies 120-127 and one of two
fluid lines 129 and 130. Precursor distribution system 128
facilitates selectively placing one or both of supplies 120-121 in
fluid communication with (purge) fluid line 129 and facilitates
selectively placing supplies 122-127 in fluid communication with
(precursor) fluid line 130. Purge fluid line 129 may carry purge
gases and Precursor fluid line 130 may carry precursors and/or
reagents and/or their respective carrier gases. Reagent subsystem
131 allows distribution of precursors/reagents from supplies 132
and 133 to be selectively placed in fluid communication with
reagent fluid lines 134 and 135, respectively. Supplies 132 and 133
may be for example, bubblers, ampoules, or solid source containers
holding organometallic or halide precursors. Appropriate inert
carrier gases (e.g., Ar 121 as shown) can be used to deliver
precursors/reagents contained in supplies 132 and 133. Examples of
precursors shown below for one embodiment include, but are not
limited to, Tetrakis-ethylmethyl amido Hafnium (TEMAHf) for supply
132 and TriMethylAluminum(TMA) for supply 133. Alternate sources of
Hafnium precursors include but are not limited to
Tetrakis-diethylamido Hafnium (TDEAHf), Tetrakis-dimethyl amido
Hafnium (TDMAHf), Hafnium tert-butoxide, Hafnium Chloride. The
choice of precursors is not limited solely to those used as
examples in the embodiment, namely Hafnium and Aluminum based
precursors for sources 132 and 133 respectively.
[0048] The fluid supply system of FIG. 6 also includes first and
second sets of injection valves 140-143 and 144-147, with injection
valves 140-143 being selectively placed in fluid communication with
reagent fluid lines 134 and 135 via reagent valve blocks 148a and
148b. Injection valves 144-147 are selectively placed in fluid
communication with (precursor) fluid line 130 via precursor valve
block 149 and with (purge) fluid line 129 via purge valve block
150. Injection valves 140-147 and valve blocks 148a, 148b, 149, and
150 may include any valve suitable for the deposition recipe,
including hi-speed (e.g., pneumatic or piezoelectric) valves.
Hi-speed valve 151 of valve block 148a selectively places injection
valves 140-143 in fluid communication with reagent fluid line 134,
and hi-speed valve 158 of valve block 148b selectively places
injection valves 140-143 in fluid communication with reagent fluid
line 135. Hi-speed valve 152 selectively places reagent fluid line
134 in fluid communication with a foreline 153 to exhaust reagent
fluids therefrom, and hi-speed valve 159 selectively places reagent
fluid line 135 in fluid communication with a foreline 153 for the
same purpose. Hi-speed valve 154 of valve block 149 selectively
places injection valve 144-147 in fluid communication with
precursor fluid line 130, and hi-speed valve 155 selectively places
precursor fluid line 130 in fluid communication with foreline 153
to exhaust reagent fluids therefrom. Purge valve block 150 also
includes a pair of hi-speed valves 156 and 157, with hi-speed valve
157 selectively placing injection valves 140-143 in fluid
communication with (purge) fluid line 129, and hi-speed valve 156
selectively placing injection valves 144-147 in fluid communication
with (purge) fluid line 129.
[0049] The components of precursor/reagent subsystems 119 and 131
may differ dependent upon the application and system
specifications. In the present embodiment subsystem 119 includes a
plurality of manual isolation valves 160, each of which is coupled
between one of supplies 120-127 and one of a plurality of two-port
valves 161. A plurality of mass flow controllers 162 are coupled
between a subset of the plurality 161 of two-port valves and a
subset of a plurality of three-port single out line valves 163. An
optional needle valve 164 is selectively placed in fluid
communication with supply 120, which may contain N.sub.2, via one
of valves 163, one of valves 161 and one of isolation valves 160,
thereby defining an exhaust path. Needle valve 164 selectively
places the exhaust path in fluid communication to a chamber vent
portion 165. Supply 126 of He may be placed in fluid communication
to the backside of the substrate to facilitate thermal coupling of
a temperature controlled (e.g., heated) pedestal to the wafer to
facilitate uniform substrate temperature control.
[0050] Referring to FIGS. 1, 5, 6 and 7, substrate processing
system 10 allows spatial and temporal modulation of the presence
and constituent components of processing fluids upon different
regions of substrate 79 to effect combinatorial process
experimentation. Valves of fluid supply system 69 are operated
under control of controller 70 such that processing fluids
propagate and are provided to quadrants 114-117 of showerhead 90
for delivery to process chamber 16 and substrate 79 located
therein. Assume that logic diagrams 184, 185, 186, 187, 188, 189,
190, 191, 192, 193, 194, 195, 196, 197, 198, 199 correspond to the
operational states of valves 159, 158, 157, 156, 155, 154, 152,
151, 147, 146, 145, 144, 143, 142, 141, 140, respectively. For each
of logic diagrams 184-199 a "0" logic state indicates that the
corresponding valves are off precluding fluid flow between the
input and output thereof, and a "1" logic state indicates that the
corresponding valve has been activated allowing fluid to propagate
between an input and output thereof. Logic diagrams 200, 201, 202,
203 and 204 correspond to the quantity of carrier flow for reagent
127 (e.g., ozone), reagent 122 (e.g., water vapor), purge fluid 121
(e.g., Ar), precursor 133 (e.g., Al containing precursor) and
precursor 132 (e.g., Hf containing precursor), respectively. As
shown, flows of precursor 133, precursor 132 and argon 121, which
may function as both a carrier and a purge fluid, are maintained by
fluid supply system 69 during processing. Through appropriate
sequential activation and deactivation of injection valves and
hi-speed valves, the choice of chemistry can be achieved above the
desired substrate in process chamber 16 at the desired time and the
desired quadrant(s).
[0051] Referring to FIG. 7, during time period 205 purge fluid 121
and precursor 132 are present in process chamber 16, however
precursor 132 flows only through quadrant 514 with its carrier gas,
while purge gas is made available in quadrants 515-517, as
described more fully below. This result is achieved due to
sequencing of hi-speed valves; valve 154 being closed and valve 155
being open directs fluids from line 130 to the foreline 153, while
valve 158 being closed and valve 159 being open directs precursor
133 through line 135 to the foreline 153, thereby by-passing the
process chamber 16. Valve 157 being closed and valve 156 being open
directs the purge gas to valves 144-147, at which point valve 144
being closed and valves 145-147 being open causes the 750 sccm
purge gas to be split evenly between quadrants 515-517. This
results in 250 standard cubic centimeters per minute (sccm) of
purge gas to flow through each of the quadrants 515-517
respectively, while only valve 140 being open in valve block
140-143 causes 250 sccm of carrier gas carrying precursor 132 to
flow through quadrant 514 with valve 151 open and valve 152 closed.
Note the total flow through the chamber during time period 205 is
1000 seem, with 250 seem each of purge gas flowing through
quadrants 515-517, and 250 sccm of carrier gas containing precursor
132 flowing through quadrant 514. It is important to note that the
amount of precursor vapor carried within the carrier gas is less
than or equal to approximately 1 sccm equivalent in most cases due
to the low vapor pressure of most precursor materials. A person
skilled in the art will appreciate that the total flow is not
limited to only 1000 sccm as used in this embodiment, however could
be any total flow (e.g. 50 to 5000 sccm) sufficient to achieve site
isolated processing dependent on chamber geometry and pumping
capacity. During time period 206, purge fluid 121 is available
throughout processing chamber 16, while both precursors 133 and 132
are diverted to the pumping system, thereby avoiding process
chamber 16 during this time period. Excess precursor 132 is removed
from the processing region 77 during this period. The precursors,
reagents and purge gases used in the process are always flowing
from the supply source and by manipulating the valve logic, they
are either made available to flow through the chamber 16 or
diverted to the pump foreline 153 (i.e., roughing pump 66 of FIG.
1). This approach avoids process inefficiencies that might occur
during the flow stabilization period of the mass flow controller or
liquid flow controllers for every given setpoint from off-state. At
this stage, quadrant 514 has been exposed to precursor and
therefore the region of surface 78 of substrate 79 corresponding to
quadrant 514 has a layer of precursor 132 adsorbed to the surface
thereof.
[0052] The valves in FIG. 6 are operated to maintain a constant
flow rather than shutting off fluid flows so as to avoid bursts and
maintain the desired flow rates when valves are opened to provide
fluid to showerhead assembly and the processing chamber. In
addition, the system is run to ensure substantially equal flows
across the regions to prevent diffusion across the boundaries. For
example, if quadrant 514 has a flow rate of 250 sccm of carrier gas
and 1 sccm equivalent of precursor, then quadrants 515-517 should
have at least 250 seem (750 sccm total) delivered to each quadrant.
The 1 sccm difference added by the precursor does not affect the
system as a whole because of the small flow differential and the
rapid flow of the fluid (short residence time) within the
processing region 77 compared to that difference. In an alternative
embodiment, the flows in the quadrants that are providing purge
gasses are made higher than the region being processed (e.g.,
containing precursors and/or reactive reagents), so that any
diffusion moves from the purged areas into the region where a film
is being grown (e.g., adsorbed or deposited). Since the purged
areas contain inert purge gas, such diffusion does not
deleteriously affect the regions being processed.
[0053] During time period 207, reagent 122 (e.g., H.sub.2O vapor)
is made available to quadrant 514, while simultaneously quadrants
515-517 are exposed to purge fluid 121, in the absence of any
additional processing fluids. During time period 207, the reagent
122 reacts with the adsorbed layer of precursor 132 on the region
of surface 78 of substrate 79 corresponding to quadrant 514 to form
a layer of the desired film (e.g., hafnium oxide). In time period
208, the chamber is purged and excess reagent 122 is removed from
the processing region 77. Time periods 205 through 208 represent
one ALD cycle and can be repeated to achieve the desired film
thickness (not shown, e.g., repeated operations during time periods
205-208 prior to moving to the operation for time period 209). It
is prudent to note that during time period 205-208, quadrants
515-517 are exposed to purge fluid 121, hence retaining the
corresponding regions of substrate 79 in their original state,
i.e., the original state being defined as the state of substrate 79
at the start of the process cycle, t=0, which corresponds to the
start of time period 205. With reference to time period 209, it is
apparent that quadrant 515 is exposed to precursor 133, while
quadrants 514, 516-517 are exposed to purge fluid 121 in the
absence of any additional processing fluids. This result is
achieved by setting the correct logic states for the valve states
as indicated in the logic state diagram. One skilled in the art
could appreciate how such processing and film growth moves
sequentially from quadrant 514 through 517 and returns to 514 for
subsequent cycles of processing.
[0054] It should be appreciated that time periods 205-208 vs.
209-212 illustrate site isolated combinatorial processing on a
substrate whereby the first precursor type is varied in addition to
the location of desired processing. Time periods 213-216
illustrates variation in the duration of the second reagent pulse
in addition to the location of desired processing. Time periods
217-220 illustrates variation in the type of the second reagent in
addition to the location of desired processing. Through careful
considerations and proper choice of precursors stored in supplies
132, 133, reagents supplied independently or in combination from
supplies 122-127, and purge fluid 120-121, it is possible to
modulate the film properties obtained across the four quadrants
514-517. Additionally, film thickness, film sequence, film stacking
(e.g., nano-laminates), film composition, co-injection (e.g. of 2
or more source precursors within one region) can be varied in a
site-isolated fashion. In addition to site isolated variation,
chamber wide process variations can include, but are not limited
to, flow rates, chamber pressures, conductance (e.g., via butterfly
valve), pulse duration(s), precursor/reagent source temperatures,
delivery line temperatures, substrate temperature, showerhead
temperature, chamber body temperature, etc. Some of these
variations are also possible to conduct in a site isolated fashion,
such as source and delivery line temperatures as well as
others.
[0055] Referring to FIGS. 1, 4, 8A and 8B, fluid distribution
system 69 allows a carrier, precursor and reagent fluid into
processing chamber 16 to provide, from the selected fluids, a
volume of fluid passing over surface 78 of substrate 79. Portions
of the fluid volume have different constituent components so that
differing regions of surface 78 of substrate 79 may be exposed to
those different constituent components at the same time. The volume
of fluid passing over surface 78 is generated by processing fluids
propagating via injection ports 94 into processing chamber 16. The
fluid distribution system enables exposing each of regions 514-517
of surface 78 to the constituent components of the portion of the
volume of fluid propagating through injection ports 94 associated
with one of showerhead sectors 114-117 corresponding therewith
(i.e., directly above or in superimposition with). Each region
514-517 of substrate 79 is exposed to the fluid volume from the
sectors 114-117 that is corresponding therewith out being exposed
to constituent components of the portion of the volume of fluid
propagating through the other sectors 114-117. In the present
example, sector 114 corresponds with region 514, sector 115
corresponds with region 515, sector 116 corresponds with region 516
and sector 117 corresponds with quadrant 517. The sectors can
correspond with other regions of the substrate, or the
corresponding sector and region can be changed during in between
processing by rotating the substrate relative to the showerhead
(e.g., by a full or partial region/quadrant).
[0056] Substrate processing system 10 operates to minimize
propagation of a portion of the processing volume produced by
processing fluids from injection ports 94 of quadrant 114 into the
remaining quadrants 115-117. Therefore, exposure of regions 515-517
of substrate surface 78 to this portion of the processing volume is
minimized. Region 514 that corresponds with quadrant 114 is exposed
to substantially the entire volume of this portion. Similarly, the
propagation of the processing volume produced by processing fluids
from a quadrant, e.g., 115-117, into the regions, e.g., 515-517,
not corresponding to, i.e., not in superimposition with, that
quadrant is minimized. Thus, the region 515, 516 and 517 that
corresponds with quadrant 115, 16 and 117, respectively, is exposed
to substantially the entire volume of that portion. The ability to
direct the flow of fluids from a sector of the showerhead to the
corresponding region on the wafer without significant lateral
diffusion (i.e., enough diffusion to effect the processing or make
comparisons between the processing of the regions unreliable)
between the regions is enabled by the showerhead design, system
pressure, fluid distribution system, fluid distribution valving,
fluid distribution, fluid flow, chamber design, system operation,
and other features discussed herein.
[0057] For example, one manner in which to ensure that the
processing fluids exiting injection ports 94 do not propagate into
a region 514-517 of surface 78 that does not correspond to the
correct one of quadrants 114-117 is by controlling the propagation
of flows of processing fluids through processing chamber 16.
Specifically, conditions are established in processing chamber 16
to generate flows of processing fluids along a direction 300
towards the substrate surface 78 and radially symmetric across and
around substrate 79 (FIGS. 1, 2, 8A and 8B), and thereby impede or
discourage movement of the processing fluids back towards
showerhead 90, i.e., opposite to direction 300. This is achieved,
in part, by fluid supply system 69 and pressure control system
(which includes pumps 64 and 66, valve 67 and channel 68, shown in
FIG. 1, and which can include other possible configurations)
operating to generate an axisymmetric flow of processing fluids
over surface 78. To that end, the pressure control system generates
a flow in pump channel 68 that results in processing fluid
propagating outwardly toward a periphery of substrate 79 shown by
arrows 304 in FIGS. 8A and 8B. Thereafter, the processing fluids
move past substrate 79 away from showerhead 90 and exit processing
chamber 16 via pump channel 68. By controlling the flow of gases,
there is little or no diffusion between the regions, as shown by
region 520 in FIG. 8B.
[0058] In one embodiment, an outer periphery of the substrate is
chosen to provide a substantially equal conductance about a
periphery of substrate 79 in response to the pumping action
generated by pumps 64 and 66. The dimensions of peripheral flow
channel 71 are defined to provide a desired conductance of
processing fluids therethrough which provide flows of processing
fluids over surface 78 of substrate 79 in a substantially uniform
and axi-symmetric fashion. The conductance through pump channel 68
is chosen to be larger than the conductance through peripheral flow
channel 71. In one embodiment, the relative conductive of
processing fluids through pump channel 68 and peripheral flow
channel 71 is, for example, 10:1, wherein the conductance of pump
channel 68 is established to be at least ten (10) times greater
than the conductance of processing fluids through peripheral flow
channel 71. Such a large disparity in the conductance, which
includes other ratios, serves to facilitate axi-symmetric flow
across the surface 78 of substrate 79 as shown by the vector flows
in FIG. 8B and flows A and B in FIG. 2 moving through processing
region 77 and subsequently passing substrate 79 and support
pedestal 48 toward pump channel 68.
[0059] In addition, in cooperation with the evacuation of
processing fluids from processing chamber 16, fluid supply system
69 controls the distribution of the processing fluids so that the
total flow through the showerhead assembly is symmetric through the
four quadrants although the constituent processing fluids per
quadrant may be altered as a function of time in one embodiment.
This serves to facilitate axi-symmetric flow. Moreover, the chamber
pressure can be controlled to a fixed pressure (e.g., 1 mTorr to 10
Torr) using butterfly valve 67 during such operations. In addition,
other chamber wide parameters can be controlled by known
techniques.
[0060] Referring to FIGS. 1, 9, and 10 pump channel 68 from FIG. 1
may be placed in other areas of chamber 16 and provide the same
axisymmetric flow necessary to prevent and/or reduce interdiffusion
between the regions, as described elsewhere herein. For example,
referring to FIG. 9, an evacuation channel 166 may be positioned so
that pump channel 160 partially or totally surrounds showerhead 90.
Although not necessary, in the present embodiment, part of
evacuation channel 166 and pump channel 160 are formed in lid 20
and are in fluid communication with pump system 64. Pump channel
160 is configured to have processing fluid propagating outwardly
toward a periphery of substrate 79 shown by arrows 304 in FIGS. 8A
and 8B. Channel 266 provides an alternative route for the process
gasses to exit to facilitate axisymmetrical flow in one embodiment
of the invention. The evacuation route is controlled by the
position of valve 67.
[0061] Referring to FIG. 10, opening 51 may facilitate evacuation
of chamber 16 by virtue of channel 168 pumping the gases from
beneath substrate pedestal 48 in a symmetric manner in order to
produce a propagation of processing fluid in an axisymmetric manner
to avoid interdiffusion between regional volumes across substrate
79, as shown by arrows 304 of FIG. 5A and vectors in FIG. 8B.
[0062] In addition to enabling combinatorial processing, the system
also allows for full wafer or conventional processing of the
substrate without a vacuum break. By flowing the same fluid through
each of passageways 30-33, each quadrants 114-117, shown in FIGS.
3, 4, and 5 of manifold body 80 will provide a flow of the same
fluid across its corresponding region of substrate 79, which
creates a uniform flow of processing fluids over the surface of
substrate 79. This facilitates the use of system 10 as a
conventional processing system, as well as a combinatorial
processing system. Therefore, the same chamber can be used to
enable conventional and combinatorial processing without
modification, except for turning selected valves on/off correctly
to distribute the desired processing fluids into chamber 16, shown
in FIG. 1. This ability enables substrate 79 to be processed with
any variation in sequence of combinatorial and conventional
processing without moving substrate 79 between tools or chambers
within one tool. Thus, these two types of processing can be
conducted without removing parts, and merely by altering the
switching logic of valves which control the gases.
[0063] Referring to FIGS. 1, 4 and 11A another embodiment of fluid
supply system 69 includes precursor/reagent subsystems 119 and 131,
valve blocks 148a, 148b and 149. An additional set of valves 150,
156, 157 and 170 are in fluid communication with passageways 30-33
to facilitate delivering processing gases to more than one of
quadrants 114-117 concurrently. To that end, valve 151 of valve
block 148a functions to selectively place fluid line 134 in fluid
communication with valves 144, 145, 146 and 147, thereby
facilitating concurrent introduction to of processing fluids into
processing chamber 16 from fluid lines 134 and 135. Valve 168
facilitates selectively placing processing fluids in fluid line 130
in fluid communication with valves 144-147, and valve 169
facilitates selectively placing processing fluids in fluid line 130
in fluid communication with valves 140-143. Valve 171 facilitates
selectively placing processing fluids in fluid line 130 in fluid
communication with valves 150, 156, 157 and 170. Greater
flexibility in the constituent components in the processing volume
proximate to surface 78 is afforded with this valve
configuration.
[0064] As shown in FIG. 11B, using the fluid supply system of FIG.
11A two regions of substrate 79, shown in FIGS. 8A and 8B, can be
exposed to precursors (same or different by region) at the same
time (i.e., in parallel), In FIG. 11B, Regions 514 and 516 are
processed in parallel in a similar fashion for the first ALD cycle
(i.e., steps 205, 206, 207, 208), whereas regions 514 and 516 are
processed in parallel in a different fashion (i.e., different
reagents in step 209) in the second ALD cycle (i.e., steps 209,
210, 211, 212). In FIG. 11B, each precursor/reagent step is
followed by a chamber purge across all regions, as shown, but Deed
not be. For example in another embodiment (not shown), after
regions 514 and 516, of FIG. 8, are exposed to a precursor(s), they
can be purged while regions 515 and 517 are concurrently exposed to
a precursor(s), etc. Other processing variations can be created
using the fluid supply system of FIG. 11A. Moreover, other valving
systems can also be created to allow all or any subset of the
regions to receive precursors or reagents in a parallel
fashion.
[0065] Referring to FIG. 12, in another embodiment, showerhead
assembly 636 is substantially identical to showerhead assembly 90
of FIGS. 3, 4, and 5, except that body 612 extends from manifold
698 disposed opposite to baffle plate (not shown) and away
therefrom. Body 612 serves the same function as body 112 and is
fabricated in a similar manner. Body 612 can be chosen so as to or
not to physically contact substrate surface 78 during processing.
It should be understood that another embodiment of the showerhead
does not require a physical barrier between the regions. Instead,
as shown in FIG. 13, a plurality of apertures 712 may be present in
which a curtain of inert gas is emitted to reduce, if not prevent,
processing fluids introduced into one sector, e.g., quadrants
114-117, from propagating into another or an adjacent sector and
thus effecting processing of the corresponding region on substrate
79.
[0066] FIGS. 13-1, 13-2, 13-3, and 13-4 illustrate exemplary
embodiments of the showerhead of FIG. 13 in accordance with one
embodiment of the invention. FIG. 13-1 illustrates a bottom
perspective view of one embodiment of the showerhead of FIG. 13.
Purge channels 712-1 and 712-2 extend across respective diameters
of the faceplate of the showerhead, thereby dividing the faceplate
into quadrants in this embodiment. Bodies 612-1 through 612-4
extend outward from the surface of the faceplate and define a
border between the quadrants and the purge channels, as well as
provide a physical barrier between the regions. Apertures 711 are
provided for fastening the faceplate to a chamber top or a baffle
plate in one embodiment. In the exemplary embodiment of FIG. 13-1
the width of purge channels 712-1 and 712-2 is about one inch. This
width is exemplary and not meant to be limiting as alternative
widths that are greater or less than one inch can be employed and
may be dependent on the application. It should be noted that the
purge channel width may be manipulated so that a test structure
residing in a center portion of a substrate undergoing a deposition
employing the showerhead described herein, is exposed only to the
purge gas. That is, no deposition occurs on the test structure in
this embodiment so that the test structure can be accessed for
characterization and screening of the combinatorial processing
described herein. Furthermore, while the faceplate in FIGS. 13-1
and 13-2 is illustrated in quadrants, this is not meant to be
limiting, as other configurations are possible. For example, the
faceplate may be divided into halves, thirds, fifths, sixths, etc.,
depending on the desired application.
[0067] FIG. 13-2 illustrates a top perspective view of one
embodiment of the showerhead of FIG. 13. In one embodiment, the
spacing (also referred to as distribution density) of injection
ports 94-1 of the quadrants and injection ports 94-2 of the purge
channel may be different. That is, the spacing of injection ports
94-2 may be smaller, greater, or equal to the corresponding spacing
of injection ports 94-1. Likewise, the diameter of injection ports
94-1 and 94-2 may be the same or different, i.e., greater than or
less than each other, as desired. Each of the quadrants and the
purge channel of FIG. 13-2 is illustrated as being slightly
recessed from sealing surface 713 in this embodiment. In FIG. 13-3,
the top of the faceplate is affixed to chamber top 715 through
appropriate fasteners, e.g., screws, extending through apertures
711. Chamber top 715 provides the connections and manifolding to
deliver process/purge gasses to be distributed into a processing
chamber through the showerhead. In FIG. 13-4 a top perspective view
of the chamber top is illustrated. Chamber top 715 is provided with
purge gas inlet 717 that provides an inlet port for the purge gas
delivery to the injection ports of the purge channel. Process gas
inlets 719-1 through 719-4 provide delivery ports for process
gasses to injection ports of the corresponding quadrants. In one
embodiment, the faceplate and a mating baffle plate provide a
plenum for distributing the gases to the injection ports of the
corresponding sectors. In this embodiment, the purge and the
process gas inlets may be integrated onto the baffle plate. Should
alternative configurations provide more or less than four sections,
i.e., the quadrant configuration, then more or less process gas
inlets may be provided, respectively. One skilled in the art will
appreciate that alternative embodiments may provide more purge gas
inlets. The number of purge gas inlets and process gas inlets is
exemplary and any number of inlets may be employed as long as a
uniform distribution of the process and purge gas is provided so
that the desired isolation of adjacent regions is maintained as
described herein. In addition, some of sections, e.g., quadrants,
may be blanked. That is, some of the sections may not include
injection ports and corresponding gas inlets. One skilled in the
art will appreciate that numerous configurations are possible for
the embodiments of FIGS. 13-1 through 13-4 and these configurations
fall within the scope of the embodiments described herein.
[0068] Another alternative embodiment is shown in FIG. 14, where
each injection port of the showerhead may each have concentrically
disposed passageways 724 and 726 so that processing fluids are kept
separated until reaching the processing chamber. These passageways
could also be adjacent instead of concentric or any other spatial
and physical arrangements that maintain separation of the gases
prior to entry in the processing chamber.
[0069] Any of the chambers or systems described in FIG. 1, 9 or 10,
or another chamber constructed according to or to implement the
inventions described herein may include a motor 310 coupled to
cause support shaft 49 and, therefore, support pedestal 48 to
rotate about a central axis. A rotary vacuum seal such as a
ferrofluidic seal can be used to maintain vacuum during rotation.
It is understood that the showerhead in the chamber could also be
rotated to create the same effect described below for the pedestal
rotation. The rotating support pedestal 48 allows the creation of
more regions on the substrate without adding more sectors on the
showerhead (e.g., either through physical barriers, inert gas
curtains, or other mechanisms). In addition, the rotation enables
the easy creation of multi-layer deposition on the substrate.
Specifically, the spatial orientation of regions on the substrate
is varied with respect to the different portions of the volume of
processing fluids, as shown in FIG. 15A, and described below in
more detail. The rotation enables changing a relative angular
position between the processing fluid volume and surface 78
multiple times, defining a sequence of angular rotations which
represent a portion of the angular sector defined by the showerhead
design.
[0070] For example, as shown in FIG. 16, first, second, third, and
fourth regions of substrate 78 are exposed to the volume of
processing fluids. The first region is bounded edges 800 and 801;
the second region is bounded by edges 801 and 802; the third region
is bounded by edges 802 and 803; and the fourth region is bounded
by edges 800 and 803. Assume that each of the first, second, third
and fourth regions are exposed to differing constituent components
of the volume.
[0071] This process produces a first layer of a first material in
the first region, a first layer of a second material in the second
region, a first layer of a third material in the third region and a
first layer of a fourth material in the fourth region. It should be
noted that one or a subset of the regions may include the gases
necessary to deposit a material or prepare the region for
deposition in a subsequent step (e.g., only the first region
process may result in a layer being formed while the other regions
are exposed to purge gas). In one example, at a second angular
position, a fifth, sixth, seventh and eighth regions may be exposed
to other constituent components of another volume of processing
fluid. The rotation of the substrate holder and substrate in this
example enables the creation of 8 regions on the substrate using
the 4 sectors defined by the showerhead. The fifth region is
bounded edges 804 and 805; the sixth region is bounded by edges 805
and 806; the seventh region is bounded by edges 806 and 807; and
the eighth region is bounded by edges 804 and 807. Assume that each
of the fifth, sixth, seventh and eighth regions are exposed to
differing constituent components of the additional volume, which
may or may not contain reactive gases, such as precursors or
reagents. This process produces different layers and materials in
each of the 8 sectors over time since each of the original
quadrants is exposed to two different fluids in the second
position.
[0072] In another embodiment, a first pair of opposing sectors can
contain first (e.g., TMAH) and second reagents (e.g., H.sub.2O) of
an ALD deposition reaction bounded by purge sectors (e.g., Ar) in
the remaining pair of opposing sectors. Substrate rotation is then
used to deposit a substantially uniform ALD film across the entire
substrate. In this embodiment, substrate rotation is used to
sequence the gases that a particular region of the substrate sees
as a function of time (e.g. TMAH+Ar purge+H.sub.20+Ar purge) as
opposed to only through gas valving and flow. Flow through each
sector is fixed and not diverted as a function of time. This
methodology has benefits of uniformity and throughput and enables
the creation of a full wafer process within the same combinatorial
ALD chamber. Modulation of the rotation speed can be used to
control the time per ALD cycle. A rotation speed of 60 revolutions
per minute corresponds to an ALD cycle time of 1 second (Reagent
1+Purge+Reagent 2+Purge). Sixty seconds of substrate rotation
during processing will equate to 60 ALD cycles.
[0073] FIG. 15A shows a simplified cross sectional view of
substrate 2179 having material formed thereon from combinatorial
processing sequences for screening purposes in accordance with one
embodiment of the invention employing the rotation described in
FIG. 16. Substrate 2179 has an electrically conductive layer 2180
disposed thereon that functions as an electrode. Layer 2180 may be
deposited using any known deposition process, including physical
vapor deposition (PVD). Deposited upon layer 2180 is a
combinatorial layer 2182 that includes four regions 2183, 2184,
2185 and 2186, each of which has different constituent components
(each of these regions can be created in a serial, semi-parallel,
or full parallel manner in accordance with the invention (as
described above). As an example, region 2183 may be formed from
Al.sub.2O.sub.3, region 2184 is formed from TiO.sub.2, region 2185
is formed HfO.sub.2, and region 2186 is formed from ZrO.sub.2.
[0074] Upon combinatorial layer 2182 is formed an additional
combinatorial layer 2187 having regions 2183, 2184, 2185 and 2186.
However, each of regions 2183, 2184, 2185 and 2186 in combinatorial
layer 2187 is shifted with respect to regions 2183, 2184, 2185 and
2186 in combinatorial layer 2182. That is, region 2183 of
combinatorial layer 2182 is in superimposition with sectors
3001-3004 of surface of conductive layer 2180; whereas, region 2183
of combinatorial layer 2187 is in superimposition with sectors
3002-3005 of surface of conductive layer 2180. This offset results
from rotation of substrate 2179 with respect to showerhead 90 after
formation of combinatorial layer 2182 and before formation of
combinatorial layer 2187. Rotation of substrate 2179 may be
undertaken between formation of each combinatorial layer, shown by
the relative position of regions 2183, 2184, 2185 and 2186 of
combinatorial layers 2188 and 2189. Formed upon combinatorial layer
2189 is a conductive feature 2190 that may be deposited by, for
example by site isolated PVD, which may be processed in a
conventional (blanket) fashion or in a combinatorial manner. This
provides a film stack having multiple regions (e.g., 16) with
different materials even though the showerhead only has 4 sectors.
Variation (e.g., process parameters, materials, thickness, etc.) of
the conductive features 2190 using site isolated combinatorial PVD
processing per sector creates additional variations in the final
film stack.
[0075] With reference to FIG. 15B it is possible to combine
different types of combinatorial processing. These different types
may include, for example, site isolated regions processed by a PVD
mask based technique and the isolated sector based system described
herein. For example, combinatorial regions 4000, 4001, 4002 may be
created with the system described herein on a substrate that
already contains regions 4003 formed with PVD or other techniques,
such as wet processing (including electroless deposition,
electrochemical deposition, cleaning, monolayer formation, etc.).
By combining these combinatorial techniques additional experiments
can be conducted and the number of substrates used can be reduced
while the amount of information gathered is increased.
[0076] It should be appreciated that FIGS. 15A and 15B illustrate
the abundance of data provided from a single substrate under the
combinatorial processing described herein. As illustrated above,
segregated portions of a fluid volume having different constituent
components flow over the surface of a substrate. These segregated
portions concurrently expose corresponding segregated sectors of
the substrate to a mixture of the constituent components that
differ from constituent components to which an adjacent segregated
sector is exposed. A layer is deposited over a segregated sector on
the substrate, wherein the layer is different from a layer
deposited on the adjacent segregated sector. The substrate may be
rotated partially, i.e., some portion of 360 degrees of rotation
and a stacked structure having different stacked layers may be
built as illustrated in FIG. 15A. In addition, the features
disposed on the stack may have differing geometries, e.g., the
segregated sectors may be pie shaped (portions of a circle), while
feature 2190 is circular.
[0077] A simplified schematic diagram illustrating an integrated
high productivity combinatorial (HPC) system in accordance with one
embodiment of the invention is shown in FIG. 17. HPC system
includes a frame 900 supporting a plurality of processing modules.
It should be appreciated that frame 900 may be a unitary frame in
accordance with one embodiment and may include multiple chambers
for ease of maintaining the vacuum and/or the addition of more
processing modules. In one embodiment, the environment within frame
900 is controlled. Load lock/factory interface 902 provides access
into the plurality of modules of the HPC system. Robot 914 provides
for the movement of substrates (and masks) between the modules and
for the movement into and out of the load lock 902. Any known
modules may be attached to the HPC System, including conventional
processing modules and combinatorial processing modules that are
necessary to support the experiments being run or a class of
structures that one wishes to test using combinatorial
techniques.
[0078] For example, Module 904 may be an orientation/degassing
module in accordance with one embodiment. Module 906 may be a clean
module, either plasma or non-plasma based, in accordance with one
embodiment of the invention. Module 908 may be the substrate
processing system described herein. Alternatively, Module 908 may
contain a plurality of masks, also referred to as processing masks,
for use in other modules of the HPC System. Module 910 includes a
HPC physical vapor deposition (PVD) module in accordance with one
embodiment of the invention, e.g., as described in U.S. application
Ser. Nos. 11/672,478, and 11/672,473. In one embodiment, a
centralized controller, i.e., computing device 911, may control the
processes of the HPC system. With HPC system, a plurality of
methods may be employed to deposit material upon a substrate
employing combinatorial processes involving PYD, ALD, CVD and
pre-post processing steps or other possible alternatives. Enabling
the combinatorial processing in one cluster tool provides for
better contaminant control, better environment control, more
precise experimentation, testing of combinatorial process sequence
integration, and better throughput when compared with shuttling the
substrate between different tools or locations. For example, the
processing shown in FIG. 15A can be conducted in one cluster tool
enabling full wafer PVD, combinatorial ALD and combinatorial PVD.
The processing illustrated with reference to FIG. 15B could be
implemented in such a system having both combinatorial PVD and ALD
or any other combination used to create structures on
substrates.
[0079] Another embodiment of the present invention, as shown in
FIGS. 18-20 may employ a vapor control device 1000 that is disposed
proximate to substrate 78 with a vapor injection apparatus 1002
disposed opposite to a vapor extraction apparatus 1004. Vapor
control device 1000 includes a plurality of spaced apart bodies
1112, which may be as described above with respect to bodies 112 or
may be implemented through other separation techniques such as
spacing or gas flow controls. During operation, vapor injection
apparatus 1002 emits processing vapors from outlets 1005, 1006,
1007 and 1008. A vapor is emitted and moves across substrate 78
assisted by a vacuum produced by vapor extraction apparatus 1004.
These flows 1114, 1115, 1116, 1117 move across regions 1118, 1119,
1120, 1121 of substrate 78. Conditions may be maintained so as to
produce a layer of material (or pre/post processing) in regions
1118, 1119, 1120, 1121 or one region or a subset of regions as
described above. The spacing shown in FIG. 19 is maintained at the
appropriate distance to enable laminar flow of the vapors to assist
in keeping the vapors separate and preventing inter-diffusion
between the regions on the substrate.
[0080] Referring to FIGS. 21, 22 and 23, the embodiments described
herein may be applied to specific applications as noted below. For
example, one of the embodiments may be directed to a process
sequence for a gate stack configuration. As the use of high
dielectric constant (referred to as High K) materials have become a
viable alternative in the manufacture of semiconductor devices,
especially for use as the gate oxide, there has been a great deal
of interest in incorporating these materials into the process
sequence for the manufacturing of semiconductor devices. However,
in order to address mobility degradation and/or threshold voltage
shifts that have been observed, an interfacial cap layer may be
disposed between the metal gate electrode and the gate oxide to
alleviate such degradation.
[0081] Referring to FIG. 23, silicon substrate 900 has High K gate
oxide 902, interfacial cap 904 and gate 906 disposed thereon. One
approach to incorporate the screening technique discussed above is
to fix the High K material being disposed over the substrate in
FIG. 21. In one embodiment, the High K material may be hafnium
silicate or hafnium oxide. Fixing the High K component refers to
performing this operation in a conventional full wafer manner
(e.g., via full wafer, non-combinatorial atomic layer deposition).
The process sequence for forming the metal gate is then varied
combinatorially. Various metals can be used initially, such as
tantalum silicon nitride, tantalum nitride, ruthenium, titanium
nitride, rhenium, platinum, etc. The HPC system described in FIG.
17 can be used to effect such site isolated processing in one
embodiment. The combinatorial vapor based system described herein
may be used, for example, for processes including metal gate layers
to adjust the effect work function of the gate electrode material.
The resulting substrate is processed through a rapid thermal
processing (RTP) step and the resulting structure of the metal over
the insulator over the semiconductor substrate is then tested. Such
tests include thermal stability, crystallization, delamination,
capacitance-voltage, flat-band voltage, effective work function
extrapolation, etc.
[0082] It may be determined that the use of a metal gate alone with
the High K gate oxide is not compatible as defects are introduced
into the structure as evidenced by testing results (e.g., effective
work function shifts). Thus, a different process sequence is
evaluated where an interfacial cap is disposed between the gate and
the gate oxide. In one embodiment, the High K processing and the
metal gate processing are fixed, while the interfacial cap
processing is varied combinatorially. The substrate is annealed
through RTP and the resulting structures are tested to identify
optimum materials, unit processes and process sequences with an
interfacial cap introduced between the High K material and the gate
material. Examples of potential interfacial cap layers include
lanthanum oxide, aluminum oxide, magnesium oxide, and scandium
oxide. The combinatorial fluid system described herein may be used,
for example, for processes including interfacial cap layers. The
RTP processing may include rapid thermal anneal.
[0083] FIGS. 24 and 25 illustrate a screening technique for
evaluating a metal-insulator-metal (MIM) structure for a memory
device element in accordance with one embodiment of the invention.
The memory device element can be, for example, a phase change,
resistive change or other memory element, such as a DRAM memory
element. The metal for this example may be a conductive element
(e.g. W, Ta, Ni, Pt, Ir, Ru, etc.) or a conductive compound (e.g.
TiN, TaN, WN, RuO.sub.2, IrO.sub.2, etc.) and forms the electrodes
for the MIM structure. The insulator is a metal oxide, such as
titanium oxide, niobium oxide, zirconium oxide, hafnium oxide,
tantalum oxide, lanthanum oxide, silicon oxide, aluminum oxide,
nickel oxide, a nano-laminate or nano-composite of any of the above
oxides, and may include any other number of interfacial or other
layers within the stack of memory materials. The insulator may be a
binary metal oxide (BMO), a complex metal oxide (CMO), a
nano-laminate, a doped or graded metal oxide, in this example. In
the DRAM memory element example, it is desirable to achieve an
optimum MIM stack exhibiting low leakage, low EOT, high effective
dielectric constant, and good thermal stability.
[0084] An optimum process sequence for this example may be
developed with the screening approach described herein. FIG. 24
illustrates a starting substrate and then a metal electrode M
(e.g., TiN) is initially deposited uniformly over the substrate,
i.e., through a conventional manufacturing process (e.g. physical
vapor deposition or sputtering). Then, site isolated processing
(e.g., using HPC system described in FIG. 17) is used to deposit
(e.g. via combinatorial physical vapor deposition or combinatorial
atomic layer deposition) the insulator layer in regions of the
substrate having the metal electrode deposited thereon. As part of
the insulator, interfacial layers may be deposited or multiple
layers may be used to form the insulator (e.g., via ALD). Items for
ALD processing that may be varied between the regions include the
precursors, reagents, carrier gases, order of precursors,
concentration of precursors/reagents, duration of precursor/reagent
pulses, purge fluid species, purge fluid duration, partial
pressures, total pressure, flow rates, film thickness, film
composition, nano-laminates (e.g. stacking of different ALD film
types), etc. The resulting substrate is post processed through RTP
(optional step) and then tested. Thus, the substrate has a metal
underlayer and the oxide is varied and then the substrate is
annealed. The testing includes adhesion properties of the layers,
resistance testing, dewetting, phase/crystallinity, and
composition. Based on the testing a certain subset (e.g.,
combinations which show poor adhesion, dewetting, or have too low a
film resistance, etc.) of the combinations are eliminated. Then,
with this reduced subset, the effect of putting another electrode
on top of the M-I structure is evaluated as depicted by FIG. 25.
Here, the bottom electrode and the insulator processes may be fixed
(or varied as shown by alternative arrows) and the top electrode is
varied. The resulting structures are annealed and tested as
described above. The testing here may include current/voltage (I/V)
testing for resistance switching (e.g., no switching, mono-stable
switching, bi-stable switching, etc.) since the MIM stack has been
constructed. As explained above, the testing is becoming more
sophisticated as the screening process proceeds to define an
optimal process sequence. The screening process determines an
optimal metal oxide and corresponding unit processes, and then
incorporates the optimal results to determine the process
interaction with a top electrode as described with reference to
FIG. 25.
[0085] Other alternative embodiments that may be claimed include a
device for distributing fluids in a semiconductor processing
chamber. The device includes a baffle plate having first and second
opposed sides with a plurality of throughways extending between the
first and the second opposed sides. The device also includes a
faceplate coupled to the baffle plate, the faceplate segmented into
sectors of injection ports extending therethrough. The segmented
sectors are defined through a fluid separation mechanism extending
radially outwardly from an axis of the faceplate. The fluid
separation mechanism facilitates sector separation of fluids
propagating through the injection ports, wherein the baffle plate
and the faceplate define a plenum when coupled together. In one
embodiment, the number of the sectors corresponds to a number of
the throughways and the fluid separation mechanism includes a body
extending from a surface of the faceplate, the body configured to
maintain separation of fluids propagating through adjacent sectors.
The body may extend away from both the surface of the faceplate and
a surface of the baffle plate, alternatively the body extends away
from the surface of the faceplate and toward a surface of the
baffle plate. The fluid separation mechanism is a set of injection
ports disposed between adjacent sectors in one embodiment. The
injection ports include first and second fluid passages, with the
second fluid passage being disposed within the first fluid passage
in one embodiment. The injection ports may include first and second
fluid passages, with the first fluid passage having a longitudinal
axis and second fluid passage being disposed within the first fluid
passage and extending along the longitudinal axis.
[0086] In another embodiment, a showerhead for distributing fluids
with a processing chamber is provided. The showerhead includes
means for independently receiving a plurality of fluid flows and
means for distributing the received plurality of fluid flows
through segmented sectors. The means for distributing is coupled to
the means for independently receiving the plurality of fluid flows.
The means for distributing includes means for maintaining
separation of the plurality of fluid flows propagating through the
means for distributing the received plurality of fluid flows
according to the segmented sectors. The number of the segmented
sectors can correspond to a number of the plurality of fluid flows.
A plenum may be defined by the coupling of the means for
independently receiving and the means for distributing. The means
for maintaining separation is selected from a group consisting of
extending from a surface of the means for distributing, extending
away from a surface of the means for distributing and away from a
surface of the means for independently receiving, extending away
from a surface of the means for distributing and towards a surface
of the means for independently receiving, and means for maintaining
separation includes means for propagating a fluid between segmented
sectors. The means for distributing includes a first means for
fluid passage defined within a second means for fluid passage and
the first means and the second means share a longitudinal axis, in
one embodiment.
[0087] In yet another embodiment a method for processing a
substrate is provided. The method includes flowing segregated
portions of a fluid volume having different constituent components
to concurrently expose corresponding segregated sectors of the
substrate to a mixture of the constituent components that differ
from constituent components to which an adjacent segregated sector
is exposed. The method includes depositing a layer on a segregated
sector on the substrate, wherein the layer is different from a
layer deposited on the adjacent segregated sector and partially
rotating the substrate. The flowing and depositing are repeated,
wherein a segment corresponding to the segregated sector in a first
layer is offset from a corresponding segment in a next layer. The
method includes varying a manufacturing parameter between the
segment and the corresponding segment and depositing a feature over
the next layer through a physical vapor deposition operation, and
wherein the deposition of the first layer and the next layer is
performed via atomic layer deposition. In one embodiment, the
segregated sectors have a first geometry and the feature has a
second geometry, e.g., the first geometry is a portion of a circle
and the second geometry is circular. Stacked layers having
different segment combinations due to the partially rotating
between depositing operations are created through the method. In
one embodiment, a number of different segment combinations exceeds
a number of segregated portions of the fluid volume.
[0088] A system for processing a substrate is provided. The system
includes means for flowing segregated portions of a fluid volume
having different constituent components to concurrently expose
corresponding segregated sectors of the substrate to a mixture of
the constituent components that differ from constituent components
to which an adjacent segregated sector is exposed. Means for
depositing a layer on a segregated sector on the substrate, wherein
the layer is different from a layer deposited on the adjacent
segregated sector are included, as well as means for partially
rotating the substrate in order to deposit a next layer over the
layer wherein the segment corresponding to the one of the
segregated sectors in the layer is offset from a corresponding
segment in the next layer. Means for varying a manufacturing
parameter between the segment and the corresponding segment and
means for depositing a feature over the next layer through a
physical vapor deposition operation are included. The segregated
sectors may have a first geometry and the feature may have a second
geometry. The system includes means for creating stacked layers
having different segment combinations due to the partially rotating
between depositing operations and wherein a number of different
segment combinations exceeds a number of segregated portions of the
fluid volume.
[0089] A substrate processing system for depositing material on a
substrate is provided. The system includes a processing chamber, a
fluid distribution system for introducing process fluids into the
processing chamber, a pressure control system in fluid
communication with the processing chamber, a rotatable support
system disposed within the processing chamber, a processor in data
communication with the fluid distribution system and the pressure
control system, and a memory in data communication with the
controller. The memory stores a program to be operated on by the
processor to control operation of the substrate processing system
to establish conditions in the processing chamber to deposit the
material. The program includes a first sub-routine to control
operation of the fluid distribution system for flowing segregated
portions of a fluid volume having different constituent components
to concurrently expose corresponding segregated sectors of a
surface of the support system to a mixture of the constituent
components that differ from constituent components to which an
adjacent segregated sector is exposed. A layer deposited on a
segregated sector is different than a layer deposited on the
adjacent segregated sector, and the rotatable support system
partially rotates between layer stacks so that adjacent layer
stacks are defined by different segment combinations. The fluid
distribution system includes a fluid distribution device to
distribute a precursor fluid and a carrier fluid over the surface,
with the fluid distribution device including a faceplate having
multiple sets of injection ports extending therethrough. A fluid
separation mechanism is disposed to facilitate separation of the
differing portions propagating through adjacent sets of the
multiple sets of injection ports. The fluid distribution system
further includes a fluid distribution device to distribute a
precursor fluid and a carrier fluid over the surface, with the
fluid distribution device including a faceplate having multiple
sets of injection ports extending therethrough, and a body
extending from the faceplate to maintain separation of the
differing portions propagating through adjacent sets of the
multiple sets of injection ports. In one embodiment, the injection
ports of one of the multiple sets are arranged along a line
extending radially from a central portion the faceplate to a
periphery thereof. The fluid distribution system directs process
fluids toward a first side of the surface and the pressure control
system evacuates the process fluids from the processing chamber
from a side of the surface disposed opposite to the first side. A
central portion of a substrate is radially symmetrically disposed
about an axis and the fluid distribution system to generate a flow
of the process fluids so that the fluid volume is radially
symmetrically disposed about the axis. The fluid distribution
system and the pressure control system operate to create a
unidirectional movement of the fluid toward and radially across the
surface. The program further includes an additional sub-routine to
control operation of the fluid distribution system to introduce a
carrier fluid and a precursor fluid into the processing chamber and
provide, from the carrier and precursor fluids, an additional fluid
volume passing over a surface of the substrate. Differing portions
of the additional fluid volume have common additional constituent
components so that each of the segregated sectors of the substrate
are exposed to a mixture of additional constituent components that
are equivalent to the additional constituent components to which an
adjacent sector of the substrate is exposed.
[0090] In another embodiment, a method of depositing material on a
substrate is provided. The method includes flowing process fluids
past opposed surfaces of the substrate so as to expose segregated
regions of one of the opposed surfaces to a mixture of constituent
components of the process fluids that differs from constituent
components of the process fluids to which adjacent regions of the
one of the opposed surfaces are exposed. Conditions are established
in an atmosphere proximate to the surface of at least one of the
regions to generate, from the process fluids, the material. The
method can include sequentially exposing the segregated regions to
deposition and purge fluids. Flows of process fluids are isolated
onto adjacent regions using flow velocities and pressure
equilibration between portions of the process fluid having
different constituent components. In one embodiment, the substrate
is rotated between flowings of the process fluids. The flowing may
include directing, toward the one of the opposed surfaces, a first
flow of a carrier gas and a second flow containing a precursor with
respective pressures being substantially equal between the first
and second flows to maintain isolation of the process fluids
containing different constituent components proximate to the one of
the opposed surfaces. In one embodiment, the process fluids are
evacuated from a side corresponding to another of the one of the
opposed surfaces, wherein the conductance for the evacuating from
the side is greater than the conductance over the one of the
opposed surfaces and the establishing creates a flow velocity that
maintains isolation of flows of the process fluids. In the method,
a central portion of the substrate is radially symmetrically
disposed about an axis and flowing further includes directing the
fluid volume to be radially symmetrically disposed about the
axis.
[0091] In another embodiment a semiconductor processing system is
provided. The system includes a fluid supply containing a plurality
of components, including carrier fluids and precursors. The fluid
supply is configured to store and deliver different mixtures of the
plurality of components. A chamber attached to a central frame
about which multiple other chambers are oriented is included. The
chamber includes a showerhead in flow communication with the fluid
supply. The showerhead is configured to receive fluid flows having
different constituent components and maintain a separation of the
components. A substrate support and a vacuum inlet coupled to a
vacuum mechanism are included. The vacuum inlet has a greater
conductance than a conductance proximate to a peripheral region of
the substrate support, wherein the fluid supply provides different
flows with substantially equal respective pressures and the vacuum
mechanism enables fluid flow velocities to maintain the fluid flows
separate in a region proximate to the substrate support. In one
embodiment, one of the other chambers is a physical vapor
deposition (PVD) module that is configured to combinatorially
process the substrate. The chamber is in flow communication with a
vacuum source for exhausting excess fluid volume of the fluid
flows, wherein an inlet to the vacuum source is separate from the
showerhead. A conductance of the inlet to the vacuum source is
greater that a conductance of a channel defined around a periphery
of the substrate support through which excess fluid volume flows to
the inlet of the vacuum source in one embodiment. The showerhead
includes a fluid separation mechanism extending radially outward
across a surface of the showerhead and may be a set of injection
ports in one embodiment.
[0092] The embodiments include a combinatorial deposition method of
forming material upon a substrate. The method includes concurrently
providing a plurality of flows of differing fluids to corresponding
portions of a showerhead. A fluid volume flows from the plurality
of flows of differing fluids, over the substrate to form a flow
pattern, wherein isolated regions of the substrate are concurrently
exposed to portions of the fluid volume having different
constituent parts. Process conditions are maintained suitable for
depositing material from one of the plurality of flows during the
flowing. A plurality of flows of equivalent fluids to corresponding
portions of the showerhead are provided and process conditions are
maintained suitable for depositing a material layer from flows of
the equivalent fluids over multiple isolated regions of the
substrate. The method includes modifying a spatial relationship
between the flow pattern of the fluid volume and the isolated
regions to change an exposure of at least one of the isolated
regions while maintaining the showerhead stationary. The modifying
may include one of rotating the substrate or manipulating valves
supplying the plurality of flows of differing fluids. The method
can include sequentially modifying the spatial relationship thereby
creating stacked layers of deposited material over the substrate.
In one embodiment, after the modifying, multiple isolated regions
are exposed to differing constituent components while purging one
of the isolated regions. Within a segment of the stacked layers
corresponding to one of the isolated regions, the segment is
composed of different material layers due to modification of the
spatial relationship. After maintaining process conditions suitable
for depositing material from one of the plurality of flows during
the flowing, the method includes combinatorially depositing a
feature over multiple segments of the stacked layers, wherein the
segments spatially correspond to the isolated regions. In one
embodiment, a number of isolated regions is greater than a number
of flows of differing fluids. In another embodiment, a lateral
diffusion region between adjacent isolated regions is maintained
proximate to a border between the adjacent isolated regions. Each
method operation may be performed in a common chamber without
breaking vacuum between depositing material and depositing the
material layer.
[0093] In another embodiment, a combinatorial deposition system is
provided. The system includes means for concurrently providing a
plurality of flows of differing fluids to a processing chamber,
means for flowing a fluid volume from the plurality of flows of
differing fluids, over a substrate to form a flow pattern, the
means for flowing concurrently exposing isolated regions of the
substrate to portions of the fluid volume having different
constituent parts. The system includes means for maintaining
process conditions suitable for depositing material from one of the
plurality of flows during the flowing and means for depositing a
substantially uniform layer of material over multiple isolated
regions of the substrate. In one embodiment, means for modifying a
spatial relationship between the flow pattern of the fluid volume
and the isolated regions to change an exposure of at least one of
the isolated regions while maintaining the showerhead stationary,
means for rotating the substrate, and means for modifying delivery
of the plurality of flows to the processing chamber are included.
The means for flowing may be a segmented showerhead, wherein a
number of segments is equal to a number of the plurality of flows
of differing fluids. Means for evacuating the processing chamber,
wherein the means for evacuating the process chamber includes an
inlet having a first conductance, the first conductance being
greater than a conductance of a channel enabling access into a
processing region of the processing chamber are provided. The flow
pattern is an axi-symmetrical flow pattern in one embodiment. In
another embodiment, the means for flowing provides linear surface
flow across the substrate from an edge of the substrate. Pressure
control means in fluid communication with the processing chamber
and the means for concurrently providing a plurality of flows, the
pressure control means configured to generate a flow of the fluid
volume in a unidirectional movement toward and radially across the
surface of the substrate can be included. The means for
concurrently providing a plurality of flows introduces a carrier
fluid and a precursor fluid into the processing chamber and
provide, from the carrier and precursor fluids, the fluid volume
passing over the surface of the substrate with portions of the
fluid volume having the different constituent components so that
differing regions of the substrate are exposed to a mixture of
constituent components that differ from the mixture of constituent
components to which an adjacent region of the substrate is exposed.
The means for concurrently providing a plurality of flows may be
configured to produce a first flow of the carrier fluid and a
second flow of the precursor fluid, impinging upon a central
portion of the means for flowing, with relative flow rates of the
first and second flows being established to equilibrate a pressure
of the portions of the fluid volume. The means for flowing includes
means for maintaining fluid separation of the plurality of flows,
the means for maintaining fluid separation disposed between
adjacent sectors of the means for flowing, the means for
maintaining fluid separation can be arranged along a line extending
radially from a central portion the means for flowing to a
periphery thereof. In one embodiment, the means for maintaining
fluid separation includes a body extending from the means for
flowing to maintain separation of fluids propagating through
adjacent sectors of the means for flowing. A central portion of the
substrate is radially symmetrically disposed about an axis and
wherein the flow pattern is radially symmetrically disposed about
the axis in one embodiment. The substantially uniform layer may be
deposited without breaking vacuum after depositing material from
one of the plurality of flows.
[0094] In yet another embodiment, a deposition system is provided.
The system includes a fluid delivery system configured to
concurrently provide a plurality of flows of fluids to a processing
chamber, and a showerhead in flow communication with the fluid
delivery system. The showerhead is configured to distribute one of
a fluid volume from the plurality of flows of differing fluids to
form a flow pattern that concurrently exposes a surface of the
system to segregated portions of the fluid volume having different
constituent parts or a fluid volume from the plurality of flows of
equivalent fluids. The system also includes a controller for
alternating between process conditions in the processing chamber
suitable for one of depositing material from a segregated portion
of the fluid volume to a mixture of the constituent components that
differ from constituent components to which adjacent regions are
exposed or depositing material from multiple flows of equivalent
fluids. A vacuum pump having an inlet into the processing chamber,
the inlet having a conductance greater than a conductance of a
channel providing access into a processing region of the processing
chamber may be included. A rotatable substrate support enabling
modification of a spatial relationship between the flow pattern and
a surface below the flow pattern through partial rotation of the
substrate support is provided in on embodiment. The showerhead may
be segmented into a number of segments that is equal to a number of
the plurality of flows. Modification of the spatial relationship
enables multiple stacked layers to be deposited onto a surface of a
substrate disposed on the rotatable substrate support, wherein two
of the multiple stacked layers have corresponding isolated regions
partially offset from each other due to the modification of the
spatial relationship between the two of the multiple stacked
layers. The fluid delivery system includes a reagent subsystem and
a precursor subsystem, the fluid delivery system further includes a
manifolding system enabling spatial modification of the fluid
volume relative to a surface over which the fluid volume flows.
[0095] In summary, the embodiments described above enable rapid and
efficient screening of materials, unit processes, and process
sequences for semiconductor manufacturing operations. Various
layers may be deposited onto a surface of a substrate
combinatorially within the same plane, on top of each other or some
combination of the two, through the atomic layer deposition tool
described herein. In one embodiment, the combinatorial process
sequencing takes a substrate out of the conventional process flow,
and introduces variation of structures or devices on a substrate in
an unconventional manner, i.e., combinatorially. However, actual
structures or devices are formed for analysis. That is, the layer,
device element, trench, via, etc., are equivalent to a layer,
device element, trench, via etc. defined through a conventional
process. The embodiments described herein can be incorporated with
any semiconductor manufacturing operation or other associated
technology, such as process operations for flat panel displays,
optoelectronics devices, data storage devices, magneto electronic
devices, magneto optic devices, packaged devices, and the like.
[0096] Although the invention has been described in terms of
specific embodiments, one skilled in the art will recognize that
various modifications may be made that are within the scope of the
present invention. For example, although four quadrants are shown,
any number of quadrants may be provided, depending upon the number
of differing process fluids employed to deposit material.
Additionally, it is possible to provide the processing volume with
a homogenous mixture of constituent components so that the
processing chamber may function as a standard processing chamber
for either ALD or CVD recipes. Therefore, the scope of the
invention should not be limited to the foregoing description.
Rather, the scope of the invention should be determined based upon
the claims recited herein, including the full scope of equivalents
thereof.
* * * * *