U.S. patent application number 12/869748 was filed with the patent office on 2010-12-23 for substrate preparation using megasonic coupling fluid meniscus.
Invention is credited to John M. Boyd, Fritz C. Redeker, Seokmin Yun.
Application Number | 20100319726 12/869748 |
Document ID | / |
Family ID | 42830832 |
Filed Date | 2010-12-23 |
United States Patent
Application |
20100319726 |
Kind Code |
A1 |
Boyd; John M. ; et
al. |
December 23, 2010 |
SUBSTRATE PREPARATION USING MEGASONIC COUPLING FLUID MENISCUS
Abstract
A method for cleaning a substrate is provided. The method
includes receiving the substrate using a carrier that forms a
circular opening, the substrate being positioned in the circular
opening of the carrier. The holding of the substrate enables
exposure of both a first side and a second side of the substrate at
a same time. Then, moving the substrate along a direction, and
while moving the substrate: (i) applying a chemistry onto the first
side of the substrate, where the first side of the substrate having
material to be removed; (ii) forming a fluid meniscus against the
second side of the substrate at a location that is opposite a
location onto which the chemistry is applied; and (iii) applying
megasonic energy to the fluid meniscus while the fluid meniscus is
applied against the second side. The megasonic energy increases
mass transport of the chemistry to enhance removal of the material
to be removed from the first side.
Inventors: |
Boyd; John M.; (Hillsboro,
OR) ; Redeker; Fritz C.; (Fremont, CA) ; Yun;
Seokmin; (Pleasanton, CA) |
Correspondence
Address: |
MARTINE PENILLA & GENCARELLA, LLP
710 LAKEWAY DRIVE, SUITE 200
SUNNYVALE
CA
94085
US
|
Family ID: |
42830832 |
Appl. No.: |
12/869748 |
Filed: |
August 27, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11240974 |
Sep 30, 2005 |
7810513 |
|
|
12869748 |
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|
10261839 |
Sep 30, 2002 |
7234477 |
|
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11240974 |
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Current U.S.
Class: |
134/1 |
Current CPC
Class: |
H01L 21/67051 20130101;
H01L 21/67028 20130101; Y10S 134/902 20130101; G03F 7/30 20130101;
H01L 21/67034 20130101; B08B 3/123 20130101 |
Class at
Publication: |
134/1 |
International
Class: |
B08B 3/12 20060101
B08B003/12 |
Claims
1. A method for enhancing a mass transport of a chemistry in a
material to be removed, the method comprising: applying the
chemistry on the material to be removed, the material to be removed
being defined on a first side of a substrate; forming a back
meniscus on a second side of the substrate opposite the applied
chemistry; applying megasonic energy to the back meniscus; and
transmitting the megasonic energy to an interface defined between
the material to be removed and the first side of the substrate
through the back meniscus, such that the mass transport of the
chemistry through the material to be removed is enhanced.
2. The method as recited in claim 1, wherein the operation of
transmitting the megasonic energy to the interface includes:
transmitting the megasonic energy to the substrate through the back
meniscus; and transmitting the megasonic energy to the interface
through the substrate.
3. The method as recited in claim 2, wherein the substrate
attenuates the megasonic energy imparted through the back
meniscus.
4. The method as recited in claim 1, the method further comprising:
reducing a temperature of the back meniscus.
5. The method as recited in claim 4, wherein the operation of
reducing the temperature of the back meniscus is configured to
decouple a temperature of the chemistry on the first side from a
temperature of a transducer generating the megasonic energy.
6. A method for cleaning a substrate, comprising: holding the
substrate using a carrier that forms a circular opening, the
substrate being positioned in the circular opening of the carrier
and held by supporting members secured to an inner rim of the
carrier, the holding of the substrate enabling exposure of both a
first side and a second side of the substrate; applying a chemistry
onto the first side of the substrate, the first side of the
substrate having material to be removed; forming a fluid meniscus
against the second side of the substrate at a location that is
opposite a location onto which the chemistry is applied; applying
megasonic energy to the fluid meniscus while the fluid meniscus is
applied against the second side; and wherein the megasonic energy
is transmitted to an interface defined between the material to be
removed and the first side of the substrate through the fluid
meniscus, such that mass transport of the chemistry through the
material to be removed is enhanced.
7. The method as recited in claim 6, wherein applying the fluid
meniscus against the second side of the substrate at the location
that is opposite the location onto which the chemistry is applied
allows for communication of energy through the substrate and to the
interface.
8. The method as recited in claim 6, wherein the substrate
attenuates the megasonic energy imparted through the fluid
meniscus.
9. The method as recited in claim 6, wherein the fluid meniscus is
a backside meniscus, and the chemistry is applied through delivery
and removal of the chemistry in meniscus form.
10. The method as recited in claim 6, the method further
comprising: reducing a temperature of the fluid meniscus.
11. The method as recited in claim 10, wherein the operation of
reducing the temperature of the fluid meniscus is configured to
decouple a temperature of the chemistry on the first side from a
temperature of a transducer generating the megasonic energy.
12. A method for cleaning a substrate, comprising: receiving the
substrate using a carrier that forms a circular opening, the
substrate being positioned in the circular opening of the carrier,
the holding of the substrate enables exposure of both a first side
and a second side of the substrate at a same time; moving the
substrate along a direction, while moving the substrate, (i)
applying a chemistry onto the first side of the substrate, the
first side of the substrate having material to be removed; (ii)
forming a fluid meniscus against the second side of the substrate
at a location that is opposite a location onto which the chemistry
is applied; and (iii) applying megasonic energy to the fluid
meniscus while the fluid meniscus is applied against the second
side; wherein the megasonic energy increases mass transport of the
chemistry to enhance removal of the material to be removed from the
first side.
13. The method as recited in claim 12, wherein applying the fluid
meniscus against the second side of the substrate at the location
that is opposite the location onto which the chemistry is applied
allows for communication of energy through the substrate and to the
interface.
14. The method as recited in claim 12, wherein the fluid meniscus
is a backside meniscus, and the chemistry is applied through
delivery and removal of the chemistry in meniscus form.
15. The method as recited in claim 12, the method further
comprising: reducing a temperature of the fluid meniscus.
16. The method as recited in claim 15, wherein the operation of
reducing the temperature of the fluid meniscus is configured to
decouple a temperature of the chemistry on the first side from a
temperature of a transducer generating the megasonic energy.
17. The method as recited in claim 12, wherein operations (i)-(iii)
are performed over a different part of the substrate as the
substrate moves.
18. The method as recited in claim 17, sensing a surface of the
substrate to determine completion of the removal of the material
after operations (i)-(iii) are completed for a portion of the
substrate.
19. The method as recited in claim 12, wherein the fluid meniscus
is temperature controlled.
20. The method as recited in claim 12, wherein applying megasonic
energy includes coupling radio frequency power to a proximity head
that provides the fluid meniscus to the second side.
Description
CLAIM OF PRIORITY
[0001] This application is a divisional application based on U.S.
patent application Ser. No. 11/240,974 filed on Sep. 30, 2005 which
is a continuation-in-part of U.S. patent application Ser. No.
10/261,839, filed on Sep. 30, 2002, and entitled "METHOD AND
APPARATUS FOR DRYING SEMICONDUCTOR WAFER SURFACES USING A PLURALITY
OF INLETS AND OUTLETS HELD IN CLOSE PROXIMITY TO THE WAFER
SURFACES," from which priority under 35 U.S.C. .sctn.120 is
claimed. The disclosure of each of the above noted applications is
incorporated herein by reference in their entirety.
BACKGROUND
[0002] The present invention relates generally to substrate
preparation and/or cleaning and, more particularly, to systems,
apparatus, and methods for improving preparation and/or cleaning of
semiconductor substrate front surfaces.
Description of the Related Art
[0003] The fabrication of semiconductor devices involves numerous
processing operations. These operations include, for example,
dopant implants, gate oxide generation, inter-metal oxide
depositions, metallization depositions, photolithography
patterning, etching operations, chemical mechanical polishing
(CMP), etc. Patterning and etching operations can be used to define
features of a semiconductor device in the semiconductor wafer. In
the patterning operation, a layer of photoresist material is
deposited onto an intermediate layer formed over the semiconductor
wafer. Thereafter, the photoresist layer is patterned by
photolithography. At this point, the semiconductor wafer is exposed
to light filtered by a reticle patterned with the desired
integrated circuit layer features. As a result of being exposed,
the light impinges upon the surface of the photoresist material,
changes the chemical composition of the photoresist material, and
creates a number of polymerized photoresist sections. The
polymerized photoresist sections are then removed using a solvent,
leaving a number of photoresist lines. At this point, the
semiconductor wafer is etched. The portions of the underlying layer
not protected by the photoresist material are removed, thus forming
the desired semiconductor device features in the semiconductor
wafer. Prior to proceeding to the next operation, however, the
photoresist lines may need to be removed, and semiconductor wafer
surfaces may need to be cleaned.
[0004] Chemicals can be used in a wet processing operation to
remove the photoresist lines. In one approach, the photoresist
lines are exposed to chemicals capable of reducing the adhesion at
the interface of the photoresist lines and the underlying layer.
Removing the photoresist lines using the latter approach requires
that batches of semiconductor wafers be placed in tanks filled with
such chemicals. Reducing the adhesion at the interface of the
photoresist lines and the underlying layer, however, requires the
soaking of the semiconductor wafers in the chemicals for an
extended period and until the photoresist material is completely
soaked. The soaking of batches of semiconductor wafers in tanks
filled with chemicals is disfavored, as chemicals can be costly,
and the wet operation can be very time consuming.
[0005] One way to expedite the removal of the photoresist material
is to couple megasonic with the operation of chemical photoresist
stripping. Achieving the latter, however, can be very costly as the
megasonic equipment and the chemicals implemented for photoresist
stripping have to be chemically compatible. Furthermore, applying
megasonic to the semiconductor wafer frontside (i.e., the active
side or top surface) can undesirably damage the semiconductor
devices, thus resulting in defective semiconductor wafers.
[0006] After removing of the photoresist lines, but before
performing the next process, the semiconductor wafers should be
cleaned so that the generated residues and particulate contaminants
adhered to the semiconductor wafer surfaces can be removed. Such
particulate contaminants can consist of tiny bits of distinctly
defined material having an affinity to adhere to the surfaces of
the substrate. Examples of particulate contaminants can include
organic and inorganic residues, such as silicon dust, silica,
slurry residue, polymeric residue, metal flakes, atmospheric dust,
plastic particles, and silicate particles, among others. Failure to
remove the particulate contaminants from the semiconductor wafer
frontside can have detrimental effects on the performance of the
semiconductor devices formed thereon, ultimately resulting in
defective semiconductor wafers.
[0007] In the same manner, failure to adequately and properly clean
and process semiconductor wafer backside (i.e., non-active side)
can be detrimental. For instance, unfortunately, residues and
contaminant particulates on semiconductor wafer backsides can
migrate from the semiconductor wafer backside to the semiconductor
wafer frontside. For example, the migration may occur during a wet
processing step and/or as the substrate is being moved or otherwise
handled between the processing or metrology tools. Additionally,
any residual fluid on the semiconductor wafer backside can migrate
to the substrate frontside, thus re-contaminating the otherwise
cleaned semiconductor wafer frontside. Furthermore, the residual
fluid maybe introduced to the otherwise cleaned and dried
substrates in the output cassette. Furthermore, the backside
contaminants can undesirably migrate from the tools or steps of one
process to tools and steps of the following processes, thus
contaminating the subsequent processes. Consequently, the migration
of residual fluid can compromise the quality of the substrate
preparation operations, and as such, is disfavored.
[0008] In view of the foregoing, there is a need for a system,
apparatus, and method capable of improving the semiconductor wafer
preparation and cleaning operations without substantially damaging
the semiconductor devices formed on the semiconductor wafer
frontsides.
SUMMARY
[0009] Broadly speaking, the present invention fills these needs by
providing a method, apparatus, and system for improving a
semiconductor substrate preparation and/or cleaning operations
without substantially damaging semiconductor devices formed on the
substrate frontsides. In one example, the present invention
improves substrate preparation and/or cleaning operations by
enhancing a mass transport of a preparation chemical to a reaction
interface defined between the material to be removed and the
substrate frontside. According to one aspect, the mass transport of
the preparation chemistry to the reaction interface is achieved by
applying megasonic energy to a backside of the substrate and the
transmission of the megasonic energy to the reaction interface
through a megasonic coupling fluid meniscus and the substrate. In
accordance with one aspect, the megasonic coupling fluid meniscus
having a lower temperature can be implemented to isolate a higher
temperature condition on the substrate frontside (i.e., the process
side) from a megasonic coupling proximity head defined on the
substrate backside.
[0010] It should be appreciated that the present invention can be
implemented in numerous ways, including as a process, an apparatus,
a system, a device, or a method. Several inventive embodiments of
the present invention are described below.
[0011] In one embodiment, method for cleaning a substrate is
provided. The method includes receiving the substrate using a
carrier that forms a circular opening, the substrate being
positioned in the circular opening of the carrier. The holding of
the substrate enables exposure of both a first side and a second
side of the substrate at a same time. Then, moving the substrate
along a direction, and while moving the substrate: (i) applying a
chemistry onto the first side of the substrate, where the first
side of the substrate having material to be removed; (ii) forming a
fluid meniscus against the second side of the substrate at a
location that is opposite a location onto which the chemistry is
applied; and (iii) applying megasonic energy to the fluid meniscus
while the fluid meniscus is applied against the second side. The
megasonic energy increases mass transport of the chemistry to
enhance removal of the material to be removed from the first
side.
[0012] According to another embodiment of the present invention, a
method for enhancing the mass transport of a chemistry in a
material to be removed is provided. The method includes applying
the chemistry on the material to be removed and forming a back
meniscus on a second side of the substrate. The material to be
removed is defined on a first side of a substrate. Megasonic energy
is applied to the back meniscus. The megasonic energy is
transmitted to an interface defined between the material to be
removed and the first side of the substrate through the back
meniscus such that the mass transport of the chemistry through the
material to be removed is enhanced.
[0013] According to yet another embodiment of the present
invention, a substrate preparation system is provided. The system
includes a proximity head and a megasonic proximity head. The
megasonic proximity head includes a resonator and a crystal. The
resonator has a first side and a second side and the first side of
the resonator faces the substrate backside. The crystal is defined
on the second side of the resonator. The vibration of the crystal
is configured to generate megasonic energy. The proximity head is
configured to be applied to a substrate frontside and is capable of
generating a preparation meniscus on the substrate frontside. The
preparation meniscus includes a preparation chemistry that is
configured to remove a material to be removed defined on the
substrate frontside. The megasonic proximity head is configured to
be applied to a substrate backside and is capable of generating
megasonic energy. The megasonic energy is configured to enhance a
mass transport of the preparation chemistry through the material to
be removed.
[0014] In accordance with still another embodiment of the present
invention, an apparatus for isolating a temperature of a process
side of a substrate is provided. The apparatus includes a megasonic
proximity head that is configured to be applied to a non-process
side of the substrate. The megasonic proximity head is capable of
generating a coupling meniscus on the non-process side of the
substrate. Lowering a temperature of the coupling meniscus is
configured to decouple the temperature of the process side of the
substrate from the non-process side of the substrate.
[0015] The advantages of the present invention are numerous. Most
notably, the present invention can substantially reduce undesirable
damage to the semiconductor devices formed over the substrate
frontside by transmission of the megasonic energy to the interface
through the substrate backside and the substrate. Furthermore,
megasonic energy is not being applied directly to the semiconductor
devices defined on the substrate frontside, thus substantially
reducing the possibility of dislodging or damaging the
semiconductor features formed therein. Yet further, enhancing the
mass transport of the preparation chemistry through the material to
be removed requires a lower level of megasonic energy.
[0016] Other aspects and advantages of the invention will become
apparent from the following detailed description, taken in
conjunction with the accompanying drawings, illustrating by way of
example the principles of the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The present invention will be readily understood by the
following detailed description in conjunction with the accompanying
drawings, and like reference numerals designate like structural
elements.
[0018] FIG. 1A is a simplified, partial, side view of an exemplary
proximity preparation system implementing an exemplary megasonic
coupling proximity head, in accordance with one embodiment of the
present invention.
[0019] FIG. 1B is a simplified, partial, magnified, cross sectional
view of the proximity preparation system depicted in FIG. 1A, in
accordance with one embodiment of the present invention.
[0020] FIG. 1C is a simplified magnification of a region A shown in
FIG. 1B, in accordance with yet another embodiment of the present
invention.
[0021] FIG. 1D is a simplified top view of an exemplary megasonic
coupling proximity head, in accordance with still another
embodiment of the present invention.
[0022] FIG. 2 depicts an exemplary semiconductor wafer preparation
system implementing an exemplary megasonic coupling proximity head
in conjunction with a two-bar-type proximity head apparatus, in
accordance with still another embodiment of the present
invention.
[0023] FIG. 3A is a simplified cross sectional view of an exemplary
megasonic coupling proximity head, in accordance with another
embodiment of the present invention.
[0024] FIG. 3B is a top view of an exemplary megasonic coupling
proximity head shown in FIG. 3A, in accordance with another
embodiment of the present invention.
[0025] FIG. 3C is a bottom view of an exemplary megasonic coupling
proximity head shown in FIG. 3A, in accordance with another
embodiment of the present invention.
[0026] FIGS. 4A shows a top view of a portion of a proximity head
in accordance with one embodiment of the present invention.
[0027] FIG. 4B illustrates an inlets/outlets pattern of a proximity
head in accordance with another embodiment of the present
invention.
[0028] FIG. 4C illustrates another inlets/outlets pattern of a
proximity head in accordance with still another embodiment of the
present invention.
[0029] FIG. 4D illustrates a further inlets/outlets pattern of a
proximity head in accordance with yet another embodiment of the
present invention.
[0030] FIG. 4E illustrates a further inlets/outlets pattern of a
proximity head in accordance with yet another embodiment of the
present invention.
DETAILED DESCRIPTION
[0031] An invention capable of improving substrate preparation
and/or cleaning operations without substantially damaging
semiconductor devices formed on substrate frontsides is provided.
In one example, the present invention improves substrate
preparation and/or cleaning operations by enhancing a mass
transport of preparation chemistry to a reaction interface on the
substrate frontside. According to one aspect, the enhancing of the
mass transport of the preparation chemistry to the reaction
interface is achieved by imparting megasonic energy to the
interface through a megasonic coupling fluid meniscus coupled to a
backside of the substrate. In one example, the megasonic energy
imparted to the reaction interface further assists in breaking a
bond or a force between the material to be removed and/or the
residues or particulate contaminants, and the substrate frontside
at the reaction interface, thus resulting in the removed of the
residues, particulate contaminants, and/or the material to be
removed.
[0032] In one aspect, the megasonic energy imparted by a megasonic
coupling proximity head is implemented to enhance the mass
transport of the preparation chemistry implemented to prepare the
substrate frontside. In one example, the megasonic energy
facilitates the moving of the molecules of the preparation
chemistry to the interface (herein also referred to as the reaction
site) (e.g., the interface between the photoresist layer and the
substrate frontside, or the interface between the residue and/or
the particulate contaminants and the substrate frontside) and
removing of the reaction by-products generated as a result of the
chemical reaction between the preparation chemistry and the
material being removed from the reaction site. In one instance,
implementing the megasonic coupling proximity head of the present
invention enhances the mass transport of the chemicals to the
reaction side and moving of the reaction by-products from the
interface.
[0033] According to one embodiment, the megasonic coupling
proximity head of present invention faces the substrate backside
and substantially opposite a proximity head configured to prepare
the semiconductor wafer frontside using a meniscus. The megasonic
energy imparted by the megasonic coupling proximity head of the
present invention is transmitted to the megasonic coupling fluid
meniscus generated by the megasonic coupling proximity head.
Thereafter, the megasonic energy is imparted to the substrate
backside and the interface. According to one embodiment, meniscus
is disclosed in U.S. patent application Ser. No. 10/261,839, filed
on Sep. 30, 2002, and entitled "METHOD AND APPARATUS FOR DRYING
SEMICONDUCTOR WAFER SURFACES USING A PLURALITY OF INLETS AND
OUTLETS HELD IN CLOSE PROXIMITY TO THE WAFER SURFACES," AND is
incorporated herein by reference in its entirety.
[0034] In one embodiment of the present invention, a cooling fluid
(e.g., nitrogen) can be introduced to an inner area of the
transducer and the backside of the crystal so as to lower the
temperature of the transducer. In another example, a higher
temperature of the meniscus being applied to the substrate
frontside can be isolated from the transducer using the megasonic
coupling fluid meniscus having a lower temperature. In one example,
a cooled megasonic fluid can be introduced into the megasonic
coupling proximity head. In this manner, the megasonic coupling
fluid meniscus having a lower temperature can be implemented to
isolate the temperature condition on the substrate frontside (i.e.,
the process side) from the transducer defined on the substrate
backside.
[0035] FIG. 1A is a simplified, partial, side view of an exemplary
proximity preparation system 100 implementing an exemplary
megasonic coupling proximity head 111, in accordance with one
embodiment of the present invention. The system 100 includes a
proximity head 110, the megasonic coupling proximity head 111, and
an RF power supply component 128. In the illustrated embodiment,
the proximity head 110 and the megasonic coupling proximity head
111 are bar-shaped and are defined on opposite sides of a
semiconductor wafer 102. The proximity head 110 faces a
semiconductor wafer frontside 102a while the megasonic coupling
proximity head 111 faces a semiconductor wafer backside 102b. While
the proximity head 110 and the megasonic coupling proximity head
111 extend the entire diameter of the semiconductor wafer 102, the
proximity head 110 and the megasonic coupling proximity head 111
partially cover the semiconductor wafer frontside and backside 102a
and 102b, respectively. The proximity head 110 is configured to
prepare the semiconductor wafer frontside 102a using a meniscus
116. As used herein, meniscus 116 is the portion of fluids (e.g.,
preparation chemistry, pre-rinse fluid, IPA vapor, DI water, etc.)
defined in a region between the proximity head 110 and the
semiconductor wafer frontside 102a.
[0036] In one example, the megasonic coupling proximity head 111 is
configured to assist the proximity head 110 in preparing the
semiconductor frontside 102a. According to one aspect, the
semiconductor wafer 102 is configured to be moved in a direction
120 while the megasonic coupling proximity head 111 and the
proximity head 110 remain stationary. In the illustrated
embodiment, the proximity head 110 is configured to strip a
photoresist layer 104 from over the semiconductor wafer 102. In
another example, the proximity head 110 can be configured to remove
any desired layer of material and/or residues and particulate
contaminants from over the semiconductor wafer frontside 102a.
[0037] As can be seen, a portion 104' of the photoresist layer 104
has already been removed from over the semiconductor wafer
frontside 102a, as depicted by the dotted lines. The portion 104'
corresponds to a processed section D of the semiconductor wafer
frontside 102a. As described in more detail below, the processing
of the section D by the proximity head 110 has been assisted by the
megasonic coupling proximity head 111 being applied to the
semiconductor wafer backside 102b.
[0038] In one example, the meniscus 116 includes a preparation
chemistry configured to strip the photoresist layer 104 from over
the semiconductor wafer frontside 102a. According to one
embodiment, the megasonic energy imparted by the megasonic coupling
proximity head 111 onto the semiconductor backside 102b is
configured to enhance the mass transport of the preparation
chemistry through the photoresist layer 104 and to an interface 103
(i.e., the interaction site) defined between the photoresist layer
104 and the semiconductor wafer frontside 102a. Mass transport
refers to the diffusion of chemicals being used to remove the
residues, particulate contaminants, and/or a layer of material
through the material to be removed and down to an interface defined
between the material to be removed and an underlying layer. The
mass transport of the preparation chemistry further includes the
removing of the by-products generated as a result of the chemical
reaction between the materials to be removed and/or the particulate
contaminants from the interface. However, as is described in more
detail below, the chemical reaction between the preparation
chemistry and the photoresist layer 104 can be a mass transport
limited reaction. That is, the preparation chemistry can diffuse
through the photoresist layer 104 (i.e., the material to be
removed) and can react with the photoresist material (i.e., the
material to be removed), generating by-products. The generated
by-products, however, cover the photoresist layer (i.e., the
material to be removed). As such, unless the generated by-products
covering the photoresist layer are removed from the interface, the
covered portions of the material to be removed cannot enter into
chemical reaction with the preparation chemistry. Consequently,
undesirably, the rate of chemical reaction is reduced. Accordingly,
the megasonic coupling proximity head of the present invention is
implemented to enhance the mass transport in a mass transport
limited reaction.
[0039] The illustrated megasonic coupling proximity head 111
includes a housing 106 and a transducer 113. A top surface 106a of
the housing 106 includes a weir 114 and faces the semiconductor
wafer backside 102b. A megasonic fluid (not shown in FIG. 1A) is
introduced into the housing 106 and ultimately into a well 120,
thus forming the megasonic coupling fluid meniscus 112. In one
example, as the megasonic coupling fluid meniscus 112 is formed and
as the semiconductor wafer backside 102b gets closer to the
megasonic coupling fluid meniscus 112, the megasonic coupling fluid
112 acts as a seal, coupling the semiconductor wafer backside 102b
to the megasonic coupling proximity head 111. Additional
information with respect to the megasonic coupling fluid 112 is
provided below with respect to FIGS. 1B-4.
[0040] The transducer 113 includes a resonator 109 and a crystal
108 defined on an inner surface of the resonator 109. In one
exemplary embodiment, the vibrations of the crystal 108 and thus
the transducer 113 create sonic energy in the megasonic coupling
fluid meniscus 112. The sonic agitation generated by the transducer
113 is thus imparted to the semiconductor wafer backside 102b
through the megasonic coupling fluid meniscus 112, and ultimately
to the interface 103. The coupled megasonic coupling fluid meniscus
enhances the mass transport of the preparation chemistry through
the photoresist layer 104 to the interface as well as assisting in
the breaking of the bond between the photoresist layer and the
semiconductor wafer frontside 102a at the interface 103.
[0041] FIG. 1B is a simplified, partial, magnified cross sectional
view of the proximity preparation system 100 depicted in FIG. 1A,
in accordance with another embodiment of the present invention.
According to one example, the housing 106 is constructed from a
chemically inert material (e.g., PET, plastics, polyurethane,
etc.). The exemplary housing 106 of the megasonic coupling
proximity head 111 includes channels 124, which extend from a
bottom surface 106b of the housing 106 to a top surface 106a of the
housing 106.
[0042] The megasonic fluid is introduced into the housing 106
through inlets 122 of the channels 124, and ultimately into the
well 120 formed between an outer surface of the resonator 109,
sidewalls 106d of the housing 106, and the top surface 106a of the
housing 106, thus forming the megasonic coupling fluid meniscus
112. As can be seen, the megasonic fluid meniscus 112 is further
confined by the semiconductor wafer backside 102b. As such, the
megasonic coupling fluid meniscus 112 seals the megasonic coupling
proximity head 112 to the semiconductor wafer backside 102b. One of
ordinary skill in the art must appreciate that although in the
illustrated embodiment the resonator 109 extends between the inner
sidewalls 106d of the housing 106, in another embodiment, the
resonator 109 can also extend along the inner sidewalls 106d of the
megasonic coupling proximity head 111 so that megasonic energy can
be imparted to the megasonic fluid while the megasonic fluid is in
the channels 124 and before being diverted into the well 120.
Furthermore, although in the illustrated embodiment the megasonic
coupling proximity head 111 includes a weir 114, in another
embodiment, a weir may not be included so long as the tolerance
required to control suction of the megasonic coupling fluid
meniscus can be achieved.
[0043] However, as shown by arrows 119, the megasonic coupling
fluid meniscus 112 can over flow over the top surface 106a of the
housing 106 and into a weir 114. Thereafter, the overflowed
megasonic coupling fluid meniscus 112 can be expelled from the
housing 106 and the weir 114 through outlets 126 of channels 127
extending from the weir 114 to the bottom surface 106b of the
housing 106. In one example, the megasonic fluid is deionized
water. Of course, in another embodiment, the megasonic fluid can be
any suitable fluid so long as the function of imparting the
megasonic energy to the interface 103 can be achieved (chemistry,
etc.).
[0044] The crystal 108 secured to the inner surface of the
resonator 109 is in communication with the RF power supply
component 128 that is configured to provide the crystal 108
electrical energy along the direction of arrows 130. In one
example, the crystal 108 is bonded to the inner surface of the
resonator 109. However, in another embodiment, the crystal 108 can
be secured to the inner surface of the resonator 109 using any
appropriate technique.
[0045] According to one example, as electrical energy is applied to
the crystal 108, the crystal 108 starts imparting energy to the
megasonic coupling fluid meniscus 112. The energy imparted to the
megasonic coupling fluid meniscus 112 is in turn passed through the
semiconductor wafer backside 102b and the semiconductor wafer 102
to the interface 103. At times, the megasonic energy can also be
imparted to the semiconductor wafer frontside 102a and the meniscus
116. In this manner, the mass transport of the preparation
chemistry is enhanced even though the megasonic energy is not being
directly imparted to the photoresist layer 104.
[0046] The megasonic coupling fluid meniscus 112 defined between
the megasonic coupling proximity head 111 and the semiconductor
wafer backside 102b, and is applied onto the semiconductor wafer
backside in a stable and controllable manner. In one embodiment,
the megasonic coupling fluid meniscus 112 may be confined by a
constant application and removal of the megasonic fluid. According
to one example, surface tension gradient technology (STG) such as
IPA vapor can be implemented to define the megasonic coupling fluid
meniscus 112. For instance, IPA can be applied so as to maintain an
encapsulated area of megasonic fluid above or below a surface, or
between surfaces. The vacuum removes the IPA and the megasonic
fluid along with any residues and/or particulate contaminants that
may reside on the semiconductor wafer backside 102b.
[0047] It must be noted that although in the illustrated embodiment
a single crystal 108 is shown to be bonded to the inner surface of
the resonator 109, in another embodiment, any appropriate number of
crystals 108 can be implemented so long as the function of
generating megasonic energy can be achieved. According to one
aspect, the transducer 113 of the present invention can include an
array of staggered crystals. Additional information with respect to
implementing array of staggered crystals is provided in U.S. patent
application Ser. No. 10/371,679, filed on Feb. 20, 2003, having
inventors Tom, Anderson and John M. Boyd, and entitled
"DISTRIBUTION OF ENERGY IN A HIGH FREQUENCY RESONATING WAFER
PROCESSING SYSTEM." The disclosure of this Application, which is
assigned to Lam Research Corporation, the assignee of the subject
application, is incorporated herein by reference.
[0048] In one embodiment, the crystal 108 may provide a movement
frequency between about 20 KHz and 500 KHz. In another
implementation, the megasonic frequency can range between
approximately about 0.5 MHz and about 2 MHz. In one example, the
crystal 108 is a piezoelectric crystal. It must be appreciated by
one of ordinary skill in the art that the piezoelectric crystals
can be made of any appropriate piezoelectric material (e.g.,
piezoelectric ceramic, lead zirconium tintanate, piezoelectric
quartz, gallium phosphate, etc.). In a like manner, the resonator
109 can be made of any appropriate material (e.g., ceramic, silicon
carbide, stainless steel, aluminum, quartz, etc.). Additionally,
one having ordinary skill in the art must appreciate that a
thickness of the piezoelectric crystal 108 depends on the design of
the crystal 108, mechanical strength of the crystal material, and
type of crystal material. In one example, the thickness of the
piezoelectric crystals is configured to range between approximately
about 1 mm and about 6 millimeter, and a more preferred range of
approximately about 2 mm and 4 mm and most preferably between
approximately about 1 mm to approximately about 2 millimeters. In
another embodiment, wherein the crystals are ceramic type crystals,
the thickness of the crystals is configured to range between
approximately about 1 mm to about 4 mm.
[0049] Preparation of the semiconductor wafer frontside 102 causing
the proximity head 110 and the application of the megasonic energy
to the semiconductor backside 102b can be advantages for several
reasons. For instance, megasonic energy is not being applied
directly to the semiconductor devices defined on the semiconductor
wafer frontside, thus substantially reducing the possibility of
dislodging or damaging the semiconductor features formed therein.
Furthermore, enhancing the mass transport of the preparation
chemistry through the material to be removed requires a lower level
of megasonic energy. Thus, in one aspect, megasonic energy having a
level lower than that of the damage threshold can be imparted to
the backside of the semiconductor wafer so as to enhance chemical
reaction at the reaction site defined on the semiconductor wafer
frontside 102a. In one example, the level of megasonic energy being
applied onto the semiconductor backside 102b can range between
about 0.1 watt per square centimeter (W/cm.sup.2) to about 10
W/cm.sup.2, and more specifically, between about 0.1 W/cm.sup.2 and
about 1 W/cm.sup.2.
[0050] Of course, the level of megasonic energy being implemented
can be higher if the megasonic coupling proximity head is being
implemented to facilitate mass transport of the preparation
chemistry on a substrate frontside having patterns that are not
sensitive to the megasonic energy, or a substrate frontside that is
not patterned. Accordingly, the megasonic coupling proximity head
of the present invention can be implemented to clean the frontside
of the semiconductor wafers depending on the topography on the
semiconductor wafer or the process being implemented.
[0051] FIG. 1C is the simplified, partial, magnified, cross
sectional view of a region A shown in FIG. 1B, illustrating the
mass transport of the preparation chemistry through the photoresist
layer 104, in accordance with one embodiment of the present
invention. As shown, a section 104a of the photoresist layer 104 is
being processed by the meniscus 116 while the section 104b has not
yet been exposed to the meniscus 116. Portions 104' of the section
104a have been removed (as shown by the dotted lines and dotted
arrows 134), whereas certain portions of the section 104a have
remained intact. Nonetheless, by the time the front meniscus 116
has passed over the section 104a of the photoresist 104, the
photoresist material in the section 104a have been removed.
[0052] As shown, the semiconductor wafer 102 attenuates portions of
the megasonic energy imparted by the megasonic coupling proximity
head 111 of the present invention. Specifically, the semiconductor
wafer 102 has attenuated the megasonic energy illustrated by arrows
130 at the interface 103, while the megasonic energy illustrated by
arrows 130' have passed through the interface 103 and have reached
the photoresist layer 104. This is beneficial because the level of
megasonic energy imparted to the semiconductor wafer frontside 102a
is below the damage threshold, thus preventing damaging of the
semiconductor devices.
[0053] FIG. 1D is a simplified top view of an exemplary megasonic
coupling proximity head, in accordance with on embodiment of the
present invention. In the illustrated embodiment, the top surface
106a of the megasonic coupling proximity head 111 has a rectangular
shape. Of course, in another embodiment, the top surface of the
megasonic coupling proximity head 111 can have any appropriate
shape so long as the function of enhancing the mass transport of
the meniscus through the material to be removed can be achieved. A
plurality of vacuum holes 114' are defined in the weir 114. In one
example, the vacuum holes 114 are used to evacuate the megasonic
coupling fluid meniscus 112 from the well 120. In another
embodiment, the megasonic coupling fluid meniscus 112 can be
removed while using STG to confine the meniscus 112 to a specific
region.
[0054] Reference is made to FIG. 2 depicting an exemplary
semiconductor wafer preparation system 200 implementing yet another
exemplary megasonic coupling proximity head in conjunction with a
two-bar-type proximity head apparatus preparation, in accordance
with one embodiment of the present invention. The system 200
includes a chamber 142, a system controller 138, and an actuating
component 136. According to one aspect, the system controller 138
controls the operations of a leading proximity head 110a, the
megasonic coupling proximity head 111, a trailing proximity head
110b, and a back proximity head 110c.
[0055] In accordance with one aspect of the present invention, the
megasonic coupling proximity head 111 is configured to assist the
leading proximity head 110a in stripping the photoresist layer 104
from over the semiconductor wafer frontside 102a. Comparatively,
the trailing proximity head 110b and the back proximity head 110c
are configured to respectively rinse and dry the semiconductor
wafer frontside 102a subsequent to the removal of the photoresist
layer 104 and the backside 102b subsequent to the cleaning of the
backside 102b by the megasonic coupling proximity head 111. Of
course, in another embodiment, the leading proximity head 110a can
be implemented to dislodge and remove residues and particulate
contaminant from over the semiconductor wafer frontside 102a.
[0056] As can be seen, the leading and trailing proximity heads
110a and 110b are defined consecutively and, are secured to an
inner sidewall of the chamber 142 by a corresponding railing 118.
In the same manner, the back proximity head 110c and the megasonic
coupling proximity head 111 are defined consecutively and are
secured to the inner wall of the chamber by the railing 118. The
trailing proximity head 110b and the back proximity head 110c are
defined opposite one another with the trailing proximity head 110b
being defined proximate to the semiconductor wafer frontside 102a
and the backside proximity head 110c being defined proximate to the
semiconductor wafer backside 102b. In the same manner, the leading
proximity head 110a and the megasonic coupling proximity head 111
are defined opposite one another with the leading proximity head
110a being proximate to the semiconductor wafer frontside 102a and
the megasonic coupling proximity head 111 being proximate to the
semiconductor wafer backside 102b. Preferably, the pair of trailing
and backside proximity heads 110b and 110c, as well as the pair of
leading proximity head 110a and the megasonic coupling proximity
head 111 are applied onto the frontside 102a and backside 102b of
the semiconductor wafer 102, substantially simultaneously.
[0057] One of ordinary in the art must recognize and appreciate
that although in the illustrated embodiment one pair of proximity
head and one pair of proximity head-megasonic coupling head have
been implemented, in a different embodiment, any appropriate number
of proximity heads can be implemented (e.g., one, two, three,
etc.). Furthermore, although in the illustrated embodiment the
leading and trailing proximity heads 110a and 110b are supported by
the single railing 118, and the back proximity head 110c and the
megasonic coupling proximity head 111 are supported by the single
railing 118, in another embodiment, each of the leading and
trailing proximity heads 110a and 110b, the back proximity head
110c, and the megasonic coupling proximity head 111 can be
supported in any appropriate configuration (e.g., each connected to
the sidewall by a respective railing, etc.).
[0058] In the illustrated embodiment, the railings 118, and thus
the respective proximity heads and megasonic coupling proximity
head are configured to be fixed. However, in a different
embodiment, the pair of trailing and back proximity heads 110b and
110c and the pair of leading proximity head 110a and megasonic
coupling proximity head 111 can be configured to move within the
chamber 104 so long as the megasonic coupling proximity head 111
can assist in the mass transport of the preparation chemistry
through the material being removed. Additionally, in the
illustrated embodiment, the semiconductor wafer 102 does not
rotate, as the entire frontside and backside 102a and 102b of the
semiconductor wafer 102 are being traversed and processed by the
leading and trailing proximity heads, back proximity head 110, and
the megasonic coupling proximity head 111.
[0059] With continued reference to FIG. 2, the carrier 144 is
coupled to the actuating component 136 via an aim 115. In one
example, the carrier 144 is a rectangular flat surface made of a
composite material (e.g., polycarbonate, coated carbon fiber,
quartz, aluminum, stainless steel, etc.). A circular opening in the
carrier 144 forms an inner rim configured to hold the semiconductor
wafer 102 to be prepared. In one example, the semiconductor wafer
102 is supported by the plurality of support members 146 secured to
the inner rim of the carrier 144. In one preferred embodiment the
support members are pins.
[0060] One of ordinary skill in the art must appreciate that
although in the illustrated embodiment the carrier 144 has a flat
rectangular surface, in another embodiment, the carrier 144 may
have any shape suitable for holding and processing the
semiconductor wafer 102. Additional information with respect to the
carrier 144 and the supporting members 146 is provided in U.S.
application Ser. No. ______ (Attorney Docket Number LAM2P521),
filed on even date herewith having inventors Katrina
Mikhaylichenko, Kenneth Dodge, Mikhail Korolik, Michael Ravkin,
John M. de Larios, and Fritz C. Redeker, and entitled "SUBSTRATE
PROXIMITY DRYING USING IN-SITU LOCAL HEATING OF SUBSTRATE AND
SUBSTRATE CARRIER POINT OF CONTACT, AND METHODS, APPARATUS, AND
SYSTEMS FOR IMPLEMENTING THE SAME." The disclosure of this
Application, which is assigned to Lam Research Corporation, the
assignee of the subject application, is incorporated herein by
reference.
[0061] In operation, the substrate frontside and backside 102a and
102b are prepared as the carrier 144 and thus the semiconductor
wafer 102 are transported horizontally in the movement direction
120 within the chamber 142. The semiconductor substrate 102 is
transported through the pair of proximity leading proximity head
110a and megasonic coupling proximity head 111 as well as the pair
of trailing and back proximity heads 110b and 110c. The megasonic
coupling fluid meniscus 112 of the megasonic coupling proximity
head 111 assists the preparation of the frontside 102a by the
meniscus 116a. Additionally, the frontside and backside 102a and
102b are prepared (e.g., rinsed and dried) by menisci 116b and
116c, respectively. In one example, the megasonic coupling fluid
meniscus 112 is configured to prepare the backside 102b by
dislodging and removing the residues and particulate contaminants
thereon.
[0062] The system controller 134 is implemented to manage and
monitor the actuating component 136 and the RF power component
during operation. In one example, the system controller 134 can be
a computer system. According to one embodiment, the actuating
component 114 provides the system controller 138 with feedbacks as
to selected parameters. In one embodiment, the actuating component
136 can be a motor, however, in a different embodiment, the
actuating component 136 can be any component capable of moving the
carrier 144 within the chamber 142. Furthermore, one of ordinary
skill in the art must appreciate that different mechanics and
engineering can be implemented to move the carrier 144 and thus the
semiconductor wafer 102 during operation.
[0063] In one aspect of the present invention, an in-situ
integrated unit such a sensor 140 can be coupled to the railing
118, between the leading proximity head 110 and trailing proximity
head 110b so as to ensure the completion of the photoresist
removal. In this manner, after the leading proximity head 110a has
prepared the semiconductor wafer frontside 102a and removed the
photoresist layer 104, the sensor 140 can inspect each portion of
the semiconductor wafer frontside 102a. Of course, the sensor 140
provides the control system 134 with feed back as to whether the
removal of the photoresist layer 104 or the residue and particulate
contaminants have been achieved properly. According to another
example, the sensor 140 can be an integrated unit within the
trailing proximity head 110b. In one aspect, the sensor 140 can use
different techniques to ensure the sufficient removal of the
photoresist layer 104 (e.g., broad band spectroscopy,
interferometry, vision system, etc.).
[0064] According to one example, a sufficient amount of energy
should be applied to the transducer 113 to generate the megasonic
energy. As a result, a significant amount of heat can be generated
at the transducer 113. Undesirably, the heat can degrade the bond
between the resonator 109 and the crystal 108, thus preventing the
transducer 113 from operating properly. Thus, in one embodiment of
the present invention, a cooling fluid (e.g., nitrogen) can be
introduced to an inner area of the transducer 113 and the backside
of the crystal 108 through an inlet 141. The cooling fluid can
thereafter be expelled using an outlet 143.
[0065] Proceeding to FIG. 3A, a simplified cross sectional view of
yet another embodiment of the megasonic coupling proximity head of
the present invention is illustrated, in accordance in one aspect
of the present invention. According to one example, the preparation
of the semiconductor wafer frontside 102a can be enhanced by using
the meniscus 116 having a higher temperature. However, the higher
temperature of the meniscus 116 can degrade the bonding between the
resonator and the crystal in the transducer. Accordingly, in one
embodiment, the temperature of the megasonic coupling fluid
meniscus 112 can be controlled so as to decouple the meniscus 116
having a higher temperature from the transducer 113. In one
example, a cooled fluid can be introduced into the megasonic
coupling proximity head so as to decouple the higher temperature of
the meniscus 116 from the transducer 113. Cooled megasonic fluid
can be introduced into the apparatus 111 through the inlets 124 and
be diverted into the well 120, forming the megasonic coupling fluid
meniscus 112. Of course, due to the cool temperature of the
megasonic fluid being introduced, the resulting megasonic coupling
fluid meniscus 112 also has a lower temperature. In this manner,
the megasonic coupling fluid meniscus 112 can be implemented to
isolate the temperature condition on the semiconductor wafer
frontside (i.e., the process side) from the transducer 113.
[0066] In the illustrated embodiment, the resonator 109 of the
transducer 113 is defined at an angle with respect to the
semiconductor wafer backside 102b. In one example, the angle
between the resonator 109 and the backside 102b can be adjusted by
adjusting an angle plate 148. For instance, by adjusting the angle
plate 148, a distance between the resonator 109 and the backside
102b can be changed. As shown in the illustrated embodiment, the
angle of the resonator 109 is reduced as the semiconductor wafer
102 is inserted between the proximity head 110a and the megasonic
coupling proximity head 111', as illustrated by the dotted
line.
[0067] FIG. 3B is a top view of an exemplary megasonic coupling
proximity head 111' shown in FIG. 3A, in accordance with another
embodiment of the present invention. In the illustrated embodiment,
megasonic fluid is configured to be introduced into the apparatus
111' through the inlets 124 so as to fill the well 120 and form the
megasonic coupling fluid meniscus 112. Overflowed megasonic
coupling fluid meniscus is configured to be diverted to the weir
114 and be eliminated from the apparatus through the outlets 126.
In one example, the overflowed megasonic coupling fluid meniscus
112 is eliminated by vacuum. The bottom view of the megasonic fluid
apparatus 111' is shown in FIG. 3C, in accordance with one
embodiment of the present invention. As can be seen, megasonic
fluid is introduced through inlets 124 and overflowed megasonic
coupling fluid meniscus is eliminated through the outlets 126.
[0068] One of ordinary skill in the art must appreciate that
although in the illustrated embodiments megasonic fluid is
introduced through two inlets 124, in another embodiment, any
appropriate number of inlets can be implemented to introduce the
megasonic fluid into the apparatus 111'. Furthermore, although in
the illustrated embodiments three outlets 126 are shown, in another
embodiment, any suitable number of outlets can be implemented to
dispose of the megasonic fluid from the apparatus 111'.
[0069] According to one embodiment of the present invention, the
megasonic coupling proximity head can be incorporated in a
clustered substrate processing system. For instance, after a
substrate frontside and/or backside has been pre-processed in an
etching chamber, a chemical vapor deposition system, a chemical
mechanical polishing (CMP) system, etc., the megasonic coupling
proximity head of the present invention can assist in preparation
of the substrate frontside and back side. Thereafter, the
semiconductor wafer backside and/or frontside can be post-processed
in an etching chamber, a chemical vapor deposition (CVD) system,
physical vapor deposition (PVD) system, electrochemical deposition
(ECD) system, an atomic layer deposition (ALD) system, a
lithographic processing system (including coater and stepper)
module, etc.
[0070] Yet further, in one exemplary implementation, the megasonic
coupling proximity head of the present invention can be implemented
in a clustered substrate cleaning apparatus that may be controlled
in an automated way by a control station. For instance, the
clustered preparation apparatus may include a sender station, a
proximity head assisted by a megasonic coupling proximity head of
the present invention, and a receiver station. Broadly stated,
substrates initially placed in the sender station are delivered,
one-at-a-time, so as to be prepared by the proximity head and the
megasonic coupling proximity head of the present invention. After
being prepared, substrates are then delivered to the receiver
station for being stored temporarily. One of ordinary skill in the
art must appreciate that in one embodiment, the clustered cleaning
apparatus can be implemented to carry out a plurality of different
substrate preparation operations (e.g., cleaning, etching, buffing,
etc.).
[0071] In an exemplary proximity system of the present invention,
preparing the substrate surfaces using a meniscus of an exemplary
proximity head is described in the following figures. One of
ordinary skill in the art must appreciate that any suitable type of
system with any suitable type of proximity head that can generate a
fluid meniscus can be used with the embodiments of the present
invention described herein.
[0072] FIG. 4A illustrates an exemplary proximity head 110'
performing a substrate processing operation, in accordance with one
embodiment of the present invention. The proximity head 110', in
one embodiment, stays in place while the carrier and thus the
substrate pass through each pair of front and back menisci 130 in
close proximity to the front and back menisci so as to conduct the
substrate processing operation.
[0073] It should be appreciated that depending on the type of fluid
applied to the semiconductor wafer 102, the fluid meniscus 116
generated by the proximity head 110' on the substrate surface 102
may be any suitable substrate processing operation such as, for
example, pre-rinsing, cleaning, drying, etc. In one embodiment, the
proximity head 110' includes source inlets 132 and 156 and a source
outlet 154. In such an embodiment, isopropyl alcohol vapor in
nitrogen gas IPA/N.sub.2 157 may be applied to the substrate
surface through a source inlet 152, vacuum 158 may be applied to
the substrate surface through a source outlet 154, and a processing
fluid may be applied to the substrate surface through a source
inlet 156.
[0074] In another embodiment, the application of the IPA/N.sub.2
157 and the processing fluid in addition to the application of the
vacuum 158 to remove the processing fluid and the IPA/N.sub.2 157
from the substrate surface 102a can generate the fluid meniscus
116. The fluid meniscus 116 may be a fluid layer defined between
the proximity head 110' and the substrate surface that can be moved
across a substrate surface 102 in a stable and controllable manner.
In one embodiment, the fluid meniscus 116 may be defined by a
constant application and removal of the processing fluid. The fluid
layer defining the fluid meniscus 116 may be any suitable shape
and/or size depending on the size, number, shape, and/or pattern of
the source inlets 156, source outlets 154, and source inlets
152.
[0075] In addition, any suitable flow rates of the vacuum,
IPA/N.sub.2, vacuum, and the processing fluid may be used depending
on the type of fluid meniscus desired to be generated. In yet
another embodiment, depending on the distance between the proximity
head 110' and the substrate surface, the IPA/N.sub.2 may be omitted
when generating and utilizing the fluid meniscus 116. In such an
embodiment, the proximity head 110' may not include the source
inlet 158 and therefore only the application of the processing
fluid by the source inlet 156 and the removal of the processing
fluid by the source outlet 154 generates the fluid meniscus
116.
[0076] In other embodiments of the proximity head 110', the
processing surface of the proximity head 110' (the region of the
proximity head where the source inlets and source outlets are
located) may have any suitable topography depending on the
configuration of the fluid meniscus 116 to be generated. In one
embodiment, the processing surface of the proximity head may be
either indented or may protrude from the surrounding surface.
[0077] FIG. 4B shows a top view of a portion of a proximity head
110' in accordance with one embodiment of the present invention. It
should be appreciated that the configuration of the proximity head
110' is exemplary in nature. Therefore, other configurations of
proximity heads 110' may be utilized to generate the fluid meniscus
116 as long as the processing fluid can be applied to a substrate
surface and removed from the substrate surface to generate a stable
fluid meniscus 116 on the substrate surface. In addition, as
discussed above, other embodiments of the proximity head 110' do
not have to have the source inlet 156 when the proximity head 110'
is configured to generate the fluid meniscus without usage of
N.sub.2/IPA.
[0078] In the top view of one embodiment, from left to right are a
set of the source inlet 152, a set of the source outlet 154, a set
of the source inlet 156, a set of the source outlet 154, and a set
of the source inlet 152. Therefore, as N.sub.2/IPA and processing
chemistry are inputted into the region between the proximity head
110' and the substrate surface, the vacuum removes the N.sub.2/IPA
and the processing chemistry along with any fluid film and/or
contaminants that may reside on the semiconductor wafer 102. The
source inlets 152, the source inlets 156, and the source outlets
154 described herein may also be any suitable type of geometry such
as for example, circular opening, triangle opening, square opening,
etc. In one embodiment, the source inlets 152 and 156 and the
source outlets 154 have circular openings. It should be appreciated
that the proximity head 110' may be any suitable size, shape,
and/or configuration depending on the size and shape of the fluid
meniscus 116 desired to generated. In one embodiment, the proximity
head may extend less than a radius of the substrate. In another
embodiment, the proximity head may extend more than the radius of
the substrate. In another embodiment, the proximity head may extend
greater than a diameter of the substrate. Therefore, the size of
the fluid meniscus may be any suitable size depending on the size
of a substrate surface area desired to be processed at any given
time. In addition, it should be appreciated that the proximity head
110' may be positioned in any suitable orientation depending on the
substrate processing operation such as, for example, horizontally,
vertically, or any other suitable position in between. The
proximity head 110' may also be incorporated into a substrate
processing system where one or more types of substrate processing
operations may be conducted.
[0079] FIG. 4C illustrates an inlets/outlets pattern of a proximity
head 110' in accordance with one embodiment of the present
invention. In this embodiment, the proximity head 110' includes the
source inlets 152 and 156 as well as source outlets 154. In one
embodiment, the source outlets 154 may surround the source inlets
156 and the source inlets 152 may surround the source outlets
154.
[0080] FIG. 4D illustrates another inlets/outlets pattern of a
proximity head 110' in accordance with one embodiment of the
present invention. In this embodiment, the proximity head 110'
includes the source inlets 152 and 156 as well as source outlets
154. In one embodiment, the source outlets 154 may surround the
source inlets 156 and the source inlets 152 may at least partially
surround the source outlets 154.
[0081] FIG. 4E illustrates a further inlets/outlets pattern of a
proximity head 110' in accordance with one embodiment of the
present invention. In this embodiment, the proximity head 110'
includes the source inlets 152 and 156 as well as source outlets
154. In one embodiment, the source outlets 154 may surround the
source inlets 156. In one embodiment, the proximity head 110' does
not include source inlets 152 because, in one embodiment, the
proximity head 110' is capable of generating a fluid meniscus
without application of IPA/N.sub.2. It should be appreciated that
the above described inlets/outlets patterns are exemplary in nature
and that any suitable type of inlets/outlets patterns may be used
as long as a stable and controllable fluid meniscus can be
generated. In one embodiment, depending on how close the proximity
head is to the surface being processed, IPA may not be utilized and
only processing fluid inlets and vacuum outlets can be used to
generate the fluid meniscus. Such an embodiment is described in
further detail in reference to U.S. application Ser. No. 10/882,835
entitled "Method And Apparatus For Processing Wafer Surfaces Using
Thin, High Velocity Fluid Layer" which is hereby incorporated by
reference in its entirety.
[0082] For additional information about the proximity vapor clean
and dry system, reference can be made to an exemplary system
described in the U.S. Pat. No. 6,488,040, issued on Dec. 3, 2002,
having inventors John M. de Larios, Mike Ravkin, Glen Travis, Jim
Keller, and Wilbur Krusell, and entitled "CAPILLARY PROXIMITY HEADS
FOR SINGLE WAFER CLEANING AND DRYING." This U.S. Patent
Application, which is assigned to Lam Research Corporation, the
assignee of the subject application, is incorporated herein by
reference.
[0083] For additional information with respect to the proximity
head, reference can be made to an exemplary proximity head, as
described in the U.S. Pat. No. 6,616,772, issued on Sep. 9, 2003,
having inventors John M. de Larios, Mike Ravkin, Glen Travis, Jim
Keller, and Wilbur Krusell, and entitled "METHODS FOR WAFER
PROXIMITY CLEANING AND DRYING." This U.S. Patent Application, which
is assigned to Lam Research Corporation, the assignee of the
subject application, is incorporated herein by reference.
[0084] For additional information about top and bottom menisci,
reference can be made to the exemplary meniscus, as disclosed in
U.S. patent application Ser. No. 10/330,843, filed on Dec. 24,
2002, having inventor Carl Woods, and entitled "MENISCUS, VACUUM,
IPA VAPOR, DRYING MANIFOLD." This U.S. Patent Application, which is
assigned to Lam Research Corporation, the assignee of the subject
application, is incorporated herein by reference.
[0085] For additional information about top and bottom menisci,
vacuum, and IPA vapor, reference can be made to the exemplary
system, as disclosed in U.S. patent application Ser. No.
10/330,897, filed on Dec. 24, 2002, having inventor Carl Woods, and
entitled "SYSTEM FOR SUBSTRATE PROCESSING WITH MENISCUS, VACUUM,
IPA VAPOR, DRYING MANIFOLD." This U.S. Patent Application, which is
assigned to Lam Research Corporation, the assignee of the subject
application, is incorporated herein by reference.
[0086] For additional information about proximity processors,
reference can be made to the exemplary processor, as disclosed in
U.S. patent application Ser. No. 10/404,270, filed on Mar. 31,
2003, having inventors James P. Garcia, Mike Ravkin, Carl Woods,
Fred C. Redeker, and John M. de Larios, and entitled "VERTICAL
PROXIMITY PROCESSOR." This U.S. Patent Application, which is
assigned to Lam Research Corporation, the assignee of the subject
application, is incorporated herein by reference.
[0087] For additional information about front and back menisci,
reference can be made to the exemplary dynamic meniscus, as
disclosed in U.S. patent application Ser. No. 10/404,692, filed on
Mar. 31, 2003, having inventors James P. Garcia, John M. de Larios,
Michael Ravkin, and Fred C. Redeker, and entitled "METHODS AND
SYSTEMS FOR PROCESSING A SUBSTRATE USING A DYNAMIC LIQUID
MENISCUS." This U.S. Patent Application, which is assigned to Lam
Research Corporation, the assignee of the subject application, is
incorporated herein by reference.
[0088] For additional information about meniscus, reference can be
made to the exemplary dynamic liquid meniscus, as disclosed in U.S.
patent application Ser. No. 10/603,427, filed on Jun. 24, 2003,
having inventors Carl A. Woods, James P. Garcia, and John M. de
Larios, and entitled "METHODS AND SYSTEMS FOR PROCESSING A BEVEL
EDGE SUBSTRATE USING A DYNAMIC LIQUID MENISCUS." This U.S. Patent
Application, which is assigned to Lam Research Corporation, the
assignee of the subject application, is incorporated herein by
reference.
[0089] For additional information about proximate cleaning and/or
drying, reference can be made to the exemplary wafer process, as
disclosed in U.S. patent application Ser. No. 10/606,022, filed on
Jun. 24, 2003, having inventors John M. Boyd, John M. de Larios,
Michael Ravkin, and Fred C. Redeker, and entitled "SYSTEM AND
METHOD FOR INTEGRATING IN-SITU METROLOGY WITHIN A WAFER PROCESS."
This U.S. Patent Application, which is assigned to Lam Research
Corporation, the assignee of the subject application, is
incorporated herein by reference.
[0090] For additional information about depositing and planarizing
thin films of semiconductor substrates, reference can be made to
the exemplary apparatus and method, as disclosed in U.S. patent
application Ser. No. 10/607,611, filed on Jun. 27, 2003, having
inventors John Boyd, Yezdi N. Dordi, and John M. de Larios, and
entitled "APPARATUS AND METHOD FOR DEPOSITING AND PLANARIZING THIN
FILMS OF SEMICONDUCTOR WAFERS." This U.S. Patent Application, which
is assigned to Lam Research Corporation, the assignee of the
subject application, is incorporated herein by reference.
[0091] For additional information about cleaning a substrate using
megasonic cleaning, reference can be made to the exemplary method
and apparatus, as disclosed in U.S. patent application Ser. No.
10/611,140, filed on Jun. 30, 2003, having inventors John M. Boyd,
Mike Ravkin, Fred C. Redeker, and John M. de Larios, and entitled
"METHOD AND APPARATUS FOR CLEANING A SUBSTRATE USING MEGASONIC
POWER." This U.S. Patent Application, which is assigned to Lam
Research Corporation, the assignee of the subject application, is
incorporated herein by reference.
[0092] For additional information about proximity brush cleaning,
reference can be made to the exemplary proximity brush, as
disclosed in U.S. patent application Ser. No. 10/742,303, filed on
Dec. 18, 2003, having inventors John M. Boyd, Michael L. Orbock,
and Fred C. Redeker, and entitled "PROXIMITY BRUSH UNIT APPARATUS
AND METHOD." This U.S. Patent Application, which is assigned to Lam
Research Corporation, the assignee of the subject application, is
incorporated herein by reference.
[0093] Various proximity heads and methods of using the proximity
heads are described in co-owned U.S. patent application Ser. No.
10/834,548 filed on Apr. 28, 2004 and entitled "APPARATUS AND
METHOD FOR PROVIDING A CONFINED LIQUID FOR IMMERSION LITHOGRAPHY,"
which is a continuation in part of U.S. patent application Ser. No.
10/606,022, filed on Jun. 24, 2003 and entitled "SYSTEM AND METHOD
FOR INTEGRATING IN-SITU METROLOGY WITHIN A WAFER PROCESS."
Additional embodiments and uses of the proximity head are also
disclosed in U.S. patent application Ser. No. 10/404,692, filed on
Mar. 31, 2003, entitled "METHODS AND SYSTEMS FOR PROCESSING A
SUBSTRATE USING A DYNAMIC LIQUID MENISCUS." Additional information
with respect to proximity cleaning can be found in U.S. patent
application Ser. No. 10/817,355 filed on Apr. 1, 2004 entitled
"SUBSTRATE PROXIMITY PROCESSING STRUCTURES AND METHODS FOR USING
AND MAKING THE SAME," U.S. patent application Ser. No. 10/817,620
filed on Apr. 1, 2004 entitled "SUBSTRATE MENISCUS INTERFACE AND
METHODS FOR OPERATION," and U.S. patent application Ser. No.
10/817,133 filed on Apr. 1, 2004 entitled "PROXIMITY MENISCUS
MANIFOLD." The aforementioned patent applications are hereby
incorporated by reference in their entirety.
[0094] Additional embodiments and uses of the proximity head are
also disclosed in U.S. patent application Ser. No. 10/330,897,
filed on Dec. 24, 2002, entitled "System for Substrate Processing
with Meniscus, Vacuum, IPA vapor, Drying Manifold" and U.S. patent
application Ser. No. 10/404,270, filed on Mar. 31, 2003, entitled
"Vertical Proximity Processor," U.S. patent application Ser. No.
10/817,398 filed on Apr. 1, 2004 entitled "Controls of Ambient
Environment During Wafer Drying Using Proximity Head," U.S. Pat.
No. 6,488,040, issued on Dec. 3, 2002, entitled "Capillary
Proximity Heads For Single Wafer Cleaning And Drying," and U.S.
Pat. No. 6,616,772, issued on Sep. 9, 2003, entitled "Methods For
Wafer Proximity Cleaning And Drying." Still further, additional
embodiments and uses of the proximity head are described in U.S.
patent application Ser. No. 10/883,301 entitled "Concentric
Proximity Processing Head," and U.S. patent application Ser. No.
10/882,835 entitled "Method and Apparatus for Processing Wafer
Surfaces Using Thin, High Velocity Fluid Layer." Further
embodiments and uses of the proximity head are further described in
U.S. patent application Ser. No. 10/957,260 entitled "Apparatus And
Method For Processing A Substrate," U.S. patent application Ser.
No. 10/956,799 entitled "Apparatus And Method For Utilizing A
Meniscus In Substrate Processing" and U.S. patent application Ser.
No. 10/957,384 entitled "Phobic Barrier Meniscus Separation And
Containment." The aforementioned patent applications are hereby
incorporated by reference in their entirety.
[0095] Although the foregoing invention has been described in some
detail for purposes of clarity of understanding, it will be
apparent that certain changes and modifications may be practiced
within the scope of the appended claims. For example, the
embodiments of the present invention can be implemented to clean
any substrate having varying sizes and shapes such as those
employed in the manufacture of semiconductor devices, flat panel
displays, hard drive discs, flat panel displays, and the like.
Additionally, the present embodiments are to be considered as
illustrative and not restrictive, and the invention is not to be
limited to the details given herein, but may be modified within the
scope and equivalents of the appended claims.
* * * * *