U.S. patent application number 13/780017 was filed with the patent office on 2013-07-11 for damascene metal gate and shield structure, methods of manufacture and design structures.
This patent application is currently assigned to INTERNATIONAL BUSINESS MACHINES CORPORATION. The applicant listed for this patent is INTERNATIONAL BUSINESS MACHINES CORPORATION. Invention is credited to Brent A. ANDERSON, Andres BRYANT, William F. CLARK, JR., John J. ELLIS-MONAGHAN, Edward J. NOWAK.
Application Number | 20130175651 13/780017 |
Document ID | / |
Family ID | 46827790 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130175651 |
Kind Code |
A1 |
ANDERSON; Brent A. ; et
al. |
July 11, 2013 |
DAMASCENE METAL GATE AND SHIELD STRUCTURE, METHODS OF MANUFACTURE
AND DESIGN STRUCTURES
Abstract
Semiconductor structures with damascene metal gates and pixel
sensor cell shields, methods of manufacture and design structures
are provided. The method includes forming a dielectric layer over a
dummy gate structure. The method further includes forming one or
more recesses in the dielectric layer. The method further includes
removing the dummy gate structure in the dielectric layer to form a
trench. The method further includes forming metal in the trench and
the one more recesses in the dielectric layer to form a damascene
metal gate structure in the trench and one or more metal components
in the one or more recesses.
Inventors: |
ANDERSON; Brent A.;
(Jericho, VT) ; BRYANT; Andres; (Burlington,
VT) ; CLARK, JR.; William F.; (Essex Junction,
VT) ; ELLIS-MONAGHAN; John J.; (Grand Isle, VT)
; NOWAK; Edward J.; (Essex Junction, VT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
INTERNATIONAL BUSINESS MACHINES CORPORATION; |
Armonk |
NY |
US |
|
|
Assignee: |
INTERNATIONAL BUSINESS MACHINES
CORPORATION
Armonk
NY
|
Family ID: |
46827790 |
Appl. No.: |
13/780017 |
Filed: |
February 28, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13051510 |
Mar 18, 2011 |
|
|
|
13780017 |
|
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Current U.S.
Class: |
257/435 ;
716/103 |
Current CPC
Class: |
H01L 27/14632 20130101;
H01L 29/66545 20130101; G06F 30/34 20200101; H01L 31/0232 20130101;
G06F 30/30 20200101; H01L 27/14683 20130101 |
Class at
Publication: |
257/435 ;
716/103 |
International
Class: |
H01L 31/0232 20060101
H01L031/0232; G06F 17/50 20060101 G06F017/50 |
Claims
1. A structure comprising a damascene metal gate and metal shield
for pixel sensor cells in a same dielectric layer, above a
sensitive component of a pixel sensor cell, wherein the metal
shield for pixel sensor cells are formed in shallow recesses in the
dielectric layer and the damascene metal gate is formed in a trench
extending to an underlying substrate formed under the dielectric
layer.
2. The structure of claim 1, wherein the dielectric layer is in
direct contact with the substrate.
3. The structure of claim 1, wherein the pixel sensor cell and the
metal shield are formed at a same level.
4. The structure of claim 1, wherein metal shield is structured and
positioned to reduce noise in the pixel sensor cell.
5. The structure of claim 1, wherein metal shield is structured and
positioned to block light from striking the sensitive component of
the pixel sensor cell.
6. The structure of claim 5, wherein the sensitive component
includes floating diffusions.
7. The structure of claim 1, wherein the metal shield is placed in
a lower level of a stack.
8. The structure of claim 1, wherein the substrate comprises
silicon on insulator (SOI) technology.
9. The structure of claim 1, wherein the recesses are about 25% to
75% of a height of the trench.
10. The structure of claim 1, wherein the metal shield comprises a
same metal as the metal gate.
11. The structure of claim 10, wherein the same metal is at least
one of titanium, titanium nitride and aluminum.
12. The structure of claim 1, wherein the metal shield is formed
about peripheries of the sensitive regions.
13. The structure of claim 1, wherein the metal shield is located
around portions or an entirety of a perimeter of a photodiode.
14. The structure of claim 1, wherein the metal shield overlaps
edges of a photodiode.
15. A hardware description language (HDL) design structure encoded
on a machine-readable data storage medium, the HDL design structure
comprising elements that when processed in a computer-aided design
system generates a machine-executable representation of a damascene
metal gate and metal shield structure on a same device level,
wherein the HDL design structure comprises a damascene metal gate
and metal shield for pixel sensor cells in a same dielectric layer,
above a sensitive component of a pixel sensor cell, wherein the
metal shield for pixel sensor cells are fondled in shallow recesses
in the dielectric layer and the damascene metal gate is formed in a
deeper trench extending to an underlying substrate formed under the
dielectric layer.
16. The design structure of claim 15, wherein the design structure
comprises a netlist.
17. The design structure of claim 15, wherein the design structure
resides on storage medium as a data format used for the exchange of
layout data of integrated circuits.
18. The design structure of claim 15, wherein the design structure
resides in a programmable gate array.
Description
FIELD OF THE INVENTION
[0001] The invention relates to semiconductor structures and
methods of manufacture and, more particularly, to semiconductor
structures with damascene metal gates and pixel sensor cell
shields, methods of manufacture and design structures.
BACKGROUND
[0002] Pixel sensor cells as well as other CMOS devices have
sensitive components that require some degree of shielding in order
to reduce, e.g., noise. For example, in pixel sensor cells, active
pixel sensor cells include photodiodes combined with a number of
active transistors which, in addition to forming an electrical
signal, provide amplification, readout control, and reset control.
However, stray light can strike sensitive areas of the active
transistors, storage areas, etc. resulting in unwanted noise.
[0003] To control this noise, CMOS processes require metal lines to
be formed in upper back end of the line metal layers, located above
the active transistors, storage areas, etc. These metal lines
shield sensitive regions from light, which would otherwise be
absorbed causing degraded performance through mechanisms such as
color crosstalk, smear, or reduced blooming control. Obviously,
this is undesirable.
[0004] However, many issues exist. By way of example, the formation
of the metal wires require additional, expensive metal fabrication
processes. Also, these metal lines are formed on upper metal wiring
layers, which require considerable space, thereby reducing the
space for other critical components, wires, interconnects, etc. For
example, in currently available CMOS fabrication processes, the
transistors are formed at a first level and the metal lines are
formed at upper metal wiring levels. However, these upper levels
are typically used for back end of the line components. Also, as
the metal lines are formed in these upper layers, incident or stray
light can still strike sensitive areas, resulting in noise and
hence performance degradation.
[0005] Accordingly, there exists a need in the art to overcome the
deficiencies and limitations described hereinabove.
SUMMARY
[0006] In a first aspect of the invention, a method comprises
forming a dielectric layer over a dummy gate structure. The method
further comprises forming one or more recesses in the dielectric
layer. The method further comprises removing the dummy gate
structure in the dielectric layer to form a trench. The method
further comprises forming metal in the trench and the one more
recesses in the dielectric layer to form a damascene metal gate
structure in the trench and one or more metal components in the one
or more recesses.
[0007] In another aspect of the invention, a structure comprises a
damascene metal gate and metal shield for pixel sensor cells in a
same dielectric layer, above a sensitive component of a pixel
sensor cell. The metal shield for pixel sensor cells are formed in
shallow recesses in the dielectric layer and the damascene metal
gate is formed in a trench extending to an underlying substrate
formed under the dielectric layer.
[0008] In another aspect of the invention, a design structure
tangibly embodied in a machine readable storage medium for
designing, manufacturing, or testing an integrated circuit is
provided. The design structure comprises the structures of the
present invention. In further embodiments, a hardware description
language (HDL) design structure encoded on a machine-readable data
storage medium comprises elements that when processed in a
computer-aided design system generates a machine-executable
representation of the structure with pixel sensor cell shields,
which comprises the structures of the present invention. In still
further embodiments, a method in a computer-aided design system is
provided for generating a functional design model of the structure
with pixel sensor cell shields. The method comprises generating a
functional representation of the structural elements of the
structure with pixel sensor cell shields.
[0009] More specifically, in an aspect of the invention, a hardware
description language (HDL) design structure is encoded on a
machine-readable data storage medium. The HDL design structure
comprises elements that when processed in a computer-aided design
system generates a machine-executable representation of a damascene
metal gate and metal shield structure on a same device level. The
HDL design structure comprises: a damascene metal gate and metal
shield for pixel sensor cells in a same dielectric layer, above a
sensitive component of a pixel sensor cell, wherein the metal
shield for pixel sensor cells are formed in shallow recesses in the
dielectric layer and the damascene metal gate is formed in a trench
extending to an underlying substrate formed under the dielectric
layer.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0010] The present invention is described in the detailed
description which follows, in reference to the noted plurality of
drawings by way of non-limiting examples of exemplary embodiments
of the present invention.
[0011] FIG. 1 shows a beginning structure and respective processing
steps in accordance with aspects of the present invention;
[0012] FIGS. 2-7 show processing steps and respective structures in
accordance with aspects of the present invention;
[0013] FIG. 8 shows a top view of a structure formed in accordance
with the methods of the present invention; and
[0014] FIG. 9 is a flow diagram of a design process used in
semiconductor design, manufacture, and/or test.
DETAILED DESCRIPTION
[0015] The invention relates to semiconductor structures and
methods of manufacture and, more particularly, to semiconductor
structures with damascene metal gates and pixel sensor cell shields
(and/or wiring), methods of manufacture and design structures. More
specifically, in one non-limiting illustrative example, the present
invention is directed to pixel sensor cells with pixel sensor cell
shields formed at a same level and in the same processing steps as
a damascene metal gate. The pixel sensor cell shields are
structured and positioned to reduce noise in the pixel sensor cell.
For example, in embodiments, the pixel sensor cell shields will
block light from striking sensitive regions in the pixel sensor
cells such as, for example, floating diffusions or other critical
components that require shielding from light, thereby reducing
unwanted noise.
[0016] Advantageously, the pixel sensor cell shields can be formed
during metal gate formation. That is, the metal gate and the pixel
sensor cell shields can be formed during a same processing step,
which eliminates additional, expensive metal fabrication steps that
would otherwise be needed to fabricate upper metal wires used to
block light, i.e., reduce noise. Also, by implementing the present
invention, it is now possible to place a light shield at a lower
level in the structure, i.e., close to the substrate, thereby
providing improved light blockage. For example, the placement of
the pixel sensor cell shields at a lower level in the stack
prevents stray light from entering at the sides of the shield,
since the incident angle is now much shallower than with
conventional shields placed at higher wiring levels. Moreover, as
the pixel sensor cell shields are now at a same level as the metal
gate, the upper metal layers, Mx, Mx+1, etc., can be used more
efficiently for metal wiring and other back end of the line devices
and structures. More particularly, additional wiring access at the
upper metal wiring levels is achieved by placing the pixel sensor
cell shields (or other wiring) at a same level as the metal
gate.
[0017] FIG. 1 shows a beginning structure and respective processing
steps in accordance with aspects of the present invention. More
specifically, FIG. 1 shows a beginning structure 5 comprising a
wafer 10. In embodiments, the wafer 10 may comprise a bulk silicon
or silicon on insulator (SOI) wafer. In the SOI implementation, the
wafer 10 comprises semiconductor layer 10b (e.g., active silicon)
formed over an insulation layer 10a. In the bulk silicon
implementation, reference numeral 10a can be representative of any
isolation region or junction isolation.
[0018] The constituent materials of the SOI wafer 10 may be
selected based on the desired end use application of the
semiconductor device. For example, the buried insulation region 10a
may be composed of oxide, such as SiO.sub.2, and may be referred to
as BOX layer. Moreover, although the SOI wafer is referred to as
"silicon on insulator," the semiconductor layer 10b is not limited
to silicon. Instead, the semiconductor layer 10b may be comprised
of various semiconductor materials, such as, for example, Si, SiGe,
SiC, SiGeC, etc. The SOI wafer 10 may be fabricated using
techniques well known to those skilled in the art. For example, the
SOI wafer 10 may be formed by conventional processes including, but
not limited to, oxygen implantation (e.g., SIMOX), wafer bonding,
etc. Active devices such as CMOS transistors can be formed in the
semiconductor layer 10b.
[0019] Still referring to FIG. 1, a dielectric layer 14 may be
formed on the semiconductor layer 10b, e.g., in direct contact with
the semiconductor layer 10b. In embodiments, the dielectric layer
14 can be a sacrificial dielectric layer, composed of any insulator
material such as, for example, oxide. In additional embodiments,
the dielectric layer 14 can be a permanent dielectric layer,
comprising any stack of insulator materials, appropriate for a
particular application. For example, the dielectric layer 14 can be
a stack of high-k dielectric material including hafnium based
materials such as, for example, hafnium oxide, and/or silicon oxy
nitride. The dielectric layer 14 can also be formed by any
conventional chemical vapor deposition (CVD) process. A polysilicon
layer 16 is formed on the dielectric layer 14 using, for example, a
CVD process.
[0020] FIG. 2 shows additional processing steps and respective
structure in accordance with aspects of the present invention. More
specifically, FIG. 2 shows the formation of a dummy gate 18. In
embodiments, the dummy gate 18 can be formed using conventional
lithographic and etching processes. For example, the lithography
step may entail applying a photoresist, exposing the photoresist to
a pattern of radiation, and developing the pattern utilizing a
conventional resist developer. Following the lithography step, a
conventional etching process such as reactive-ion etching (RIE) may
be employed in transferring the pattern to the dummy gate 18.
[0021] In FIG. 3, a dielectric material (e.g., dielectric stack) 20
is formed over the dummy gate 18. In embodiments, the dielectric
material 20 comprises any conventional inter-level dielectric
material such as, for example, oxide. In embodiments, the
dielectric material 20 is deposited using conventional deposition
methods such as, for example, CVD. The dielectric material 20 can
completely surround the dummy gate 18.
[0022] In FIG. 4, the dielectric material 20 is polished to expose
a top surface 18a of the dummy gate 18. In embodiments, the top
surface 18a of the dummy gate 18 can also be polished. The
polishing can be any conventional polishing process such as, for
example, chemical mechanical polishing.
[0023] As shown in FIG. 5, recesses 22 are formed in the dielectric
material 20. The recesses 22 can be formed using any conventional
lithographic and etching processes, as discussed above. In
embodiments, the recesses 22 can be formed independent of the dummy
gate (e.g., trenches 24) or directly in contact with the dummy
gate. In further embodiments, the recesses 22 are formed over
sensitive components/devices such as, for example, floating
diffusions or other sensitive components of a pixel sensor cell in
which light would affect the signal. In further embodiments, the
recesses 22 can be formed about peripheries of such sensitive
components/devices, even including, in embodiments, around portions
or an entirety of a perimeter of the photodiode. In embodiments,
the recesses 22 should not be formed directly over the light
sensitive portions of the photodiode, as this will ensure that
light can be captured by the photodiode in order to generate a
signal.
[0024] The recesses 22 are designed as a percentage of the height
of the dummy gate. For example, in embodiments, the recesses 22 can
be about 25% to 75% of the height of the dummy gate; although other
dimensions are also contemplated by the present invention. As an
illustrative example, the recesses 22 can be about 40 nm in depth,
which would require a 100 nm high dummy gate. In embodiments,
advantageously, the remaining thickness of the dielectric material
20 between the layer 10b and the recesses 22 can reduce capacitance
of the structure.
[0025] Still referring to FIG. 5, the dummy gate 18 can also be
removed to form one or more trenches 24. The dummy gates can be
removed using a selective chemistry to the polysilicon. That is,
the removal process will remove dummy gate material at a higher
removal rate than the dielectric material 20 and the dielectric
layer 14. In embodiments, the dielectric layer 14 can also be
removed; although, it is contemplated that the dielectric layer 14
will remain at the bottom of the trench 24. In one preferred
embodiment, the recesses 22 are formed prior to the formation of
the trench 24 so as to prevent any contamination in the transistor
region.
[0026] As shown in FIG. 6, the recesses and the trench are filled
with a metal during a same processing step to form pixel sensor
cell shields 26 and a metal gate 28 (at a same level). The use of
the same processing step eliminates expensive metal fabrication
steps that would otherwise be needed to fabricate metal wires
typically used to block light, i.e., reduce noise. The metal can be
planarized in order to form discrete, separate metal patterns.
[0027] In embodiments, the metal can be any gate metal or
combination of gate metals such as, for example, titanium, titanium
nitride and/or aluminum. As should be understood by those of skill
in the art, the metals can be adjusted for specific work functions.
In any scenario, the metals can be formed using any conventional
deposition methods such as, for example, metal sputtering. In
embodiments, the metal within the trench can be deposited directly
on the dielectric layer 14; however, if the dielectric layer was
previously removed during the formation of the trench, the present
invention contemplates the deposition of a new dielectric layer(s)
prior to the deposition of the metal gate layer. In embodiments,
the metal layer can be polished.
[0028] As shown in FIG. 6, in embodiments, the pixel sensor cell
shields 26 can be formed near (above) sensitive components/devices
such as, for example, floating diffusions, sensitive components of
a pixel sensor cell in which light would affect the signal or other
critical logic (represented at reference numeral 29). In further
embodiments, the pixel sensor cell shields 26 can be formed about
peripheries (edges or portions thereof) of such sensitive
components/devices, even including, in embodiments, around portions
or an entirety of a perimeter of the photodiode 31. In embodiments,
the pixel sensor cell shields 26 can even slightly overlap the
edges of the photodiode 31 or critical logic circuits. As should
now be understood by those of skill in the art, the pixel sensor
cell shields 26 will prevent stray light from striking the
sensitive components, e.g., sensitive portions of the pixel sensor
cell, thereby reducing overall noise. Also, due to the sufficient
separation of the pixel sensor cell shields 26 from the underlying
structures, parasitic capacitance between the shields 26 and the
substrate 10b can be reduced.
[0029] In FIG. 7, a capping layer 30 is formed over the pixel
sensor cell shields 26 and the metal gate 28. In embodiments, the
capping layer 30 can be, for example, a SiN capping layer. The
capping layer 30 can be formed using any conventional deposition
method such as, for example, CVD. Back end of the line (BEOL)
layer(s) 32 are formed on the capping layer 30. The BEOL layer(s)
32 can be any upper wiring layer, used for the formation of
interconnects, wirings, dual damascene copper layers, etc.
[0030] FIG. 8 shows a top view of a structure formed in accordance
with the methods of the present invention. As shown in this view,
the pixel sensor cell shields 26 are provided at strategic
locations around a edges (represented by the dashed lines) or
portions thereof of a structure, e.g., photodiode 31, or as shown
at reference numeral 26a above an entirety or substantially an
entirety of other critical logic circuits such as, for example,
floating diffusions 29. In the implementation of the floating
diffusions, the pixel sensor cell shields 26a can cover the
entirety of the collection region in order to prevent stray light
from entering such sensitive areas. The pixel sensor cell shields
26 are also located near the metal gate 28, at the same level.
[0031] FIG. 9 is a flow diagram of a design process used in
semiconductor design, manufacture, and/or test. FIG. 9 shows a
block diagram of an exemplary design flow 900 used for example, in
semiconductor IC logic design, simulation, test, layout, and
manufacture. Design flow 900 includes processes, machines and/or
mechanisms for processing design structures or devices to generate
logically or otherwise functionally equivalent representations of
the design structures and/or devices described above and shown in
FIGS. 1-8. The design structures processed and/or generated by
design flow 900 may be encoded on machine-readable transmission or
storage media to include data and/or instructions that when
executed or otherwise processed on a data processing system
generate a logically, structurally, mechanically, or otherwise
functionally equivalent representation of hardware components,
circuits, devices, or systems. Machines include, but are not
limited to, any machine used in an IC design process, such as
designing, manufacturing, or simulating a circuit, component,
device, or system. For example, machines may include: lithography
machines, machines and/or equipment for generating masks (e.g.
e-beam writers), computers or equipment for simulating design
structures, any apparatus used in the manufacturing or test
process, or any machines for programming functionally equivalent
representations of the design structures into any medium (e.g. a
machine for programming a programmable gate array).
[0032] Design flow 900 may vary depending on the type of
representation being designed. For example, a design flow 900 for
building an application specific IC (ASIC) may differ from a design
flow 900 for designing a standard component or from a design flow
900 for instantiating the design into a programmable array, for
example a programmable gate array (PGA) or a field programmable
gate array (FPGA) offered by Altera.RTM. Inc. or Xilinx.RTM.
Inc.
[0033] FIG. 9 illustrates multiple such design structures including
an input design structure 920 that is preferably processed by a
design process 910. Design structure 920 may be a logical
simulation design structure generated and processed by design
process 910 to produce a logically equivalent functional
representation of a hardware device. Design structure 920 may also
or alternatively comprise data and/or program instructions that
when processed by design process 910, generate a functional
representation of the physical structure of a hardware device.
Whether representing functional and/or structural design features,
design structure 920 may be generated using electronic
computer-aided design (ECAD) such as implemented by a core
developer/designer. When encoded on a machine-readable data
transmission, gate array, or storage medium, design structure 920
may be accessed and processed by one or more hardware and/or
software modules within design process 910 to simulate or otherwise
functionally represent an electronic component, circuit, electronic
or logic module, apparatus, device, or system such as those shown
in FIGS. 1-8. As such, design structure 920 may comprise files or
other data structures including human and/or machine-readable
source code, compiled structures, and computer-executable code
structures that when processed by a design or simulation data
processing system, functionally simulate or otherwise represent
circuits or other levels of hardware logic design. Such data
structures may include hardware-description language (HDL) design
entities or other data structures conforming to and/or compatible
with lower-level HDL design languages such as Verilog and VHDL,
and/or higher level design languages such as C or C++.
[0034] Design process 910 preferably employs and incorporates
hardware and/or software modules for synthesizing, translating, or
otherwise processing a design/simulation functional equivalent of
the components, circuits, devices, or logic structures shown in
FIGS. 1-8 to generate a netlist 980 which may contain design
structures such as design structure 920. Netlist 980 may comprise,
for example, compiled or otherwise processed data structures
representing a list of wires, discrete components, logic gates,
control circuits, I/O devices, models, etc. that describes the
connections to other elements and circuits in an integrated circuit
design. Netlist 980 may be synthesized using an iterative process
in which netlist 980 is resynthesized one or more times depending
on design specifications and parameters for the device. As with
other design structure types described herein, netlist 980 may be
recorded on a machine-readable data storage medium or programmed
into a programmable gate array. The medium may be a non-volatile
storage medium such as a magnetic or optical disk drive, a
programmable gate array, a compact flash, or other flash memory.
Additionally, or in the alternative, the medium may be a system or
cache memory, buffer space, or electrically or optically conductive
devices and materials on which data packets may be transmitted and
intermediately stored via the Internet, or other networking
suitable means.
[0035] Design process 910 may include hardware and software modules
for processing a variety of input data structure types including
netlist 980. Such data structure types may reside, for example,
within library elements 930 and include a set of commonly used
elements, circuits, and devices, including models, layouts, and
symbolic representations, for a given manufacturing technology
(e.g., different technology nodes, 32 nm, 45 nm, 90 nm, etc.). The
data structure types may further include design specifications 940,
characterization data 950, verification data 960, design rules 970,
and test data files 985 which may include input test patterns,
output test results, and other testing information. Design process
910 may further include, for example, standard mechanical design
processes such as stress analysis, thermal analysis, mechanical
event simulation, process simulation for operations such as
casting, molding, and die press forming, etc. One of ordinary skill
in the art of mechanical design can appreciate the extent of
possible mechanical design tools and applications used in design
process 910 without deviating from the scope and spirit of the
invention. Design process 910 may also include modules for
performing standard circuit design processes such as timing
analysis, verification, design rule checking, place and route
operations, etc.
[0036] Design process 910 employs and incorporates logic and
physical design tools such as HDL compilers and simulation model
build tools to process design structure 920 together with some or
all of the depicted supporting data structures along with any
additional mechanical design or data (if applicable), to generate a
second design structure 990.
[0037] Design structure 990 resides on a storage medium or
programmable gate array in a data format used for the exchange of
data of mechanical devices and structures (e.g. information stored
in a IGES, DXF, Parasolid XT, JT, DRG, or any other suitable format
for storing or rendering such mechanical design structures).
Similar to design structure 920, design structure 990 preferably
comprises one or more files, data structures, or other
computer-encoded data or instructions that reside on transmission
or data storage media and that when processed by an ECAD system
generate a logically or otherwise functionally equivalent form of
one or more of the embodiments of the invention shown in FIGS. 1-8.
In one embodiment, design structure 990 may comprise a compiled,
executable HDL simulation model that functionally simulates the
devices shown in FIGS. 1-8.
[0038] Design structure 990 may also employ a data format used for
the exchange of layout data of integrated circuits and/or symbolic
data format (e.g. information stored in a GDSII (GDS2), GL1, OASIS,
map files, or any other suitable format for storing such design
data structures). Design structure 990 may comprise information
such as, for example, symbolic data, map files, test data files,
design content files, manufacturing data, layout parameters, wires,
levels of metal, vias, shapes, data for routing through the
manufacturing line, and any other data required by a manufacturer
or other designer/developer to produce a device or structure as
described above and shown in FIGS. 1-8. Design structure 990 may
then proceed to a stage 995 where, for example, design structure
990: proceeds to tape-out, is released to manufacturing, is
released to a mask house, is sent to another design house, is sent
back to the customer, etc.
[0039] The method as described above is used in the fabrication of
integrated circuit chips. The resulting integrated circuit chips
can be distributed by the fabricator in raw wafer form (that is, as
a single wafer that has multiple unpackaged chips), as a bare die,
or in a packaged form. In the latter case the chip is mounted in a
single chip package (such as a plastic carrier, with leads that are
affixed to a motherboard or other higher level carrier) or in a
multichip package (such as a ceramic carrier that has either or
both surface interconnections or buried interconnections). In any
case the chip is then integrated with other chips, discrete circuit
elements, and/or other signal processing devices as part of either
(a) an intermediate product, such as a motherboard, or (b) an end
product. The end product can be any product that includes
integrated circuit chips, ranging from toys and other low-end
applications to advanced computer products having a display, a
keyboard or other input device, and a central processor.
[0040] The terminology used herein is for the purpose of describing
particular embodiments only and is not intended to be limiting of
the invention. As used herein, the singular forms "a", "an" and
"the" are intended to include the plural forms as well, unless the
context clearly indicates otherwise. It will be further understood
that the terms "comprises" and/or "comprising," when used in this
specification, specify the presence of stated features, integers,
steps, operations, elements, and/or components, but do not preclude
the presence or addition of one or more other features, integers,
steps, operations, elements, components, and/or groups thereof.
[0041] The corresponding structures, materials, acts, and
equivalents of all means or step plus function elements in the
claims, if applicable, are intended to include any structure,
material, or act for performing the function in combination with
other claimed elements as specifically claimed. The description of
the present invention has been presented for purposes of
illustration and description, but is not intended to be exhaustive
or limited to the invention in the form disclosed. Many
modifications and variations will be apparent to those of ordinary
skill in the art without departing from the scope and spirit of the
invention. The embodiment was chosen and described in order to best
explain the principals of the invention and the practical
application, and to enable others of ordinary skill in the art to
understand the invention for various embodiments with various
modifications as are suited to the particular use contemplated.
Accordingly, while the invention has been described in terms of
embodiments, those of skill in the art will recognize that the
invention can be practiced with modifications and in the spirit and
scope of the appended claims.
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