US20140175597A1 - Trench with reduced silicon loss - Google Patents
Trench with reduced silicon loss Download PDFInfo
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- US20140175597A1 US20140175597A1 US14/190,229 US201414190229A US2014175597A1 US 20140175597 A1 US20140175597 A1 US 20140175597A1 US 201414190229 A US201414190229 A US 201414190229A US 2014175597 A1 US2014175597 A1 US 2014175597A1
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- Prior art keywords
- trench
- semiconductor device
- sidewall
- isolation trench
- slope
- Prior art date
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- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 title description 6
- 229910052710 silicon Inorganic materials 0.000 title description 6
- 239000010703 silicon Substances 0.000 title description 6
- 238000002955 isolation Methods 0.000 claims abstract description 32
- 239000004065 semiconductor Substances 0.000 claims abstract description 20
- 239000000758 substrate Substances 0.000 claims abstract description 16
- 230000007704 transition Effects 0.000 claims abstract description 9
- 239000000463 material Substances 0.000 claims description 4
- 229910021420 polycrystalline silicon Inorganic materials 0.000 abstract description 22
- 229920005591 polysilicon Polymers 0.000 abstract description 22
- 238000005530 etching Methods 0.000 abstract description 3
- 239000000945 filler Substances 0.000 abstract 1
- 229910052581 Si3N4 Inorganic materials 0.000 description 7
- 238000000034 method Methods 0.000 description 7
- 229920002120 photoresistant polymer Polymers 0.000 description 7
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 7
- 230000003628 erosive effect Effects 0.000 description 3
- 230000015572 biosynthetic process Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 238000000151 deposition Methods 0.000 description 1
- 230000008021 deposition Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
- H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
- H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
- H01L29/0603—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions
- H01L29/0642—Isolation within the component, i.e. internal isolation
- H01L29/0649—Dielectric regions, e.g. SiO2 regions, air gaps
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
- H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
- H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
- H01L21/30—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26
- H01L21/302—Treatment of semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/26 to change their surface-physical characteristics or shape, e.g. etching, polishing, cutting
- H01L21/306—Chemical or electrical treatment, e.g. electrolytic etching
- H01L21/308—Chemical or electrical treatment, e.g. electrolytic etching using masks
- H01L21/3083—Chemical or electrical treatment, e.g. electrolytic etching using masks characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane
- H01L21/3086—Chemical or electrical treatment, e.g. electrolytic etching using masks characterised by their size, orientation, disposition, behaviour, shape, in horizontal or vertical plane characterised by the process involved to create the mask, e.g. lift-off masks, sidewalls, or to modify the mask, e.g. pre-treatment, post-treatment
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
- H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
- H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
- H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
- H01L21/76—Making of isolation regions between components
- H01L21/762—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers
- H01L21/76224—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers using trench refilling with dielectric materials
- H01L21/76232—Dielectric regions, e.g. EPIC dielectric isolation, LOCOS; Trench refilling techniques, SOI technology, use of channel stoppers using trench refilling with dielectric materials of trenches having a shape other than rectangular or V-shape, e.g. rounded corners, oblique or rounded trench walls
Definitions
- This invention relates to the field of semiconductor devices. More particularly, this invention relates to trench isolation in semiconductor devices.
- STI shallow trench isolation
- the trenches In instances where the voltage is higher, the trenches must either be made wider or deeper to support the higher voltage.
- Increasing the active pitch (trench opening width plus active geometry width) by making the trenches wider is the more manufacturable solution, but it also causes the area of the integrated circuit to increase thus reducing the number of chips that may be formed on a wafer with a resultant increase in cost per chip.
- Making the trenches deeper while keeping the active pitch constant is difficult because trench etch tends to increase the width of the trench opening for deeper trenches. This results in a decrease in the width of the active width resulting in reduced transistor drive current.
- an isolation trench in a substrate of a semiconductor device has a shallower portion and a deeper portion and a transition region between the deeper portion and the shallower portion.
- a slope of a sidewall of the transition region sidewall is less vertical than a slope of a sidewall of the shallower portion and is less vertical than a slope of a sidewall of the deeper portion.
- the isolation trench contains a dielectric fill material.
- the isolation trench is formed by forming a first portion of the isolation trench in a substrate of the semiconductor device; forming polysilicon sidewalls on walls of the first portion; etching the substrate below the first portion to form a second portion of the isolation trench; and filling the isolation trench with a dielectric fill material.
- FIG. 1A through 1H are illustrations of steps in the fabrication of a semiconductor device formed according to a first embodiment.
- FIG. 2A through 2H are illustrations of steps in the fabrication of a semiconductor device formed according to a second embodiment.
- FIGS. 1A through 1H A method of forming an isolation trench with increased depth without increasing active pitch according to an embodiment is described in FIGS. 1A through 1H .
- FIG. 1A shows a semiconductor device 1000 having a semiconductor substrate 1002 upon which a pad oxide 1004 is grown and a silicon nitride film 1006 is deposited.
- An active photo resist pattern 1008 is formed on substrate 1002 .
- Photo resist pattern 1008 has openings 1010 in which isolation trenches are to be formed.
- FIG. 1B shows semiconductor device 1000 after the silicon nitride film 1006 and the pad oxide layer 1004 are etched and isolation trench 1112 is partially etched into substrate 1002 .
- a first portion of isolation trench 1112 may be etched to a depth of 100 to 500 nm. Etching a minimum width trench deeper may result in erosion of the top of the trench opening causing the top of the trench 1114 to widen and the active width 1116 to become narrower. If the active width 1116 is a transistor channel this will decrease the transistor width with a resulting decrease in transistor drive current which is undesirable.
- a layer of polysilicon 1220 is deposited over the partially etched trench as shown in FIG. 1C and then etched to form sidewalls 1324 as shown in FIG. 1D .
- a thin pad dielectric 1218 may optionally be deposited or grown on the surface of trench 1112 .
- the thin pad dielectric 1218 may be an oxide that is 3 to 9 nm thick and the layer of polysilicon 1220 may be 5 to 15 nm thick.
- the trench 1112 is then etched to full depth which may be 200 to 1000 nm deep as shown in FIG. 1E .
- the polysilicon sidewalls 1324 protect the sidewalls of the upper portion 1426 of the trench 1112 from erosion while the lower portion 1428 of the trench 1112 is being etched. Since trench etch is a silicon etch, the polysilicon sidewalls may be partially consumed during the etch of the lower portion 1428 of the trench 1112 . During the lower portion etch approximately 5 nm of the polysilicon sidewall may be etched. Optionally, the thickness of the polysilicon sidewall 1324 may be optimized so that it is completely consumed during etch of the lower portion of the trench.
- the trench 1112 is shown in FIG. 1F after the polysilicon sidewall 1324 and pad oxide 1218 (if present) are removed. If the polysilicon sidewall thickness is completely consumed during the etch of the lower portion 1428 of the trench 1112 the step of removing the polysilicon sidewall is omitted.
- the lower portion 1428 of the trench 1112 which was etched with the polysilicon sidewalls in place may have a more vertical sidewall slope 1534 than the sidewall slope 1530 of the upper portion 1426 of the trench 1112 .
- the trench 1112 is filled with dielectric 1638 and the dielectric is planarized as shown in FIGS. 1G and 1H using commonly used procedures.
- the trench may be first lined with a dielectric 1636 such as oxide or oxide plus nitride or a nitrided oxide.
- the liner dielectric may be thermally grown or deposited using a CVD process for example.
- the trench may then be filled with a dielectric 1638 such as sub atmospheric chemical vapor deposition (SACVD) oxide, high density plasma (HDP) oxide or high aspect ratio (HARP) oxide as shown in FIG. 1G .
- SACVD sub atmospheric chemical vapor deposition
- HDP high density plasma
- HTP high aspect ratio
- FIG. 1H shows the integrated circuit 1000 after planarization by chemical mechanical polishing (CMP) and removal of the silicon nitride film 1006 and the pad oxide layer 1004 .
- CMP chemical mechanical polishing
- Additional processing then may be performed to build transistors and other electrical devices and also to build the interconnection layers to complete the integrated circuit.
- FIGS. 2A through 2G One embodiment in which both deep and shallow isolation trenches are simultaneously formed is illustrated in FIGS. 2A through 2G .
- pad oxide 2004 is grown and silicon nitride film 2006 is deposited on silicon substrate 2002 of semiconductor device 2000 .
- a first active photoresist pattern 2008 is then formed over silicon substrate 2002 with openings 2010 where the deep isolation trenches which may be used to isolate high voltage devices are to be formed.
- a first portion 2114 of deep isolation trench 2112 is etched and active photoresist pattern 2008 is removed as shown in FIG. 2B .
- the photo resist pattern 2008 may be removed prior to or post trench etch. It is preferred to remove the pattern 2008 after the silicon nitride layer 2006 and pad oxide layer 2004 have been etched and before the silicon substrate 2002 is etched to reduce etch microloading effects which may cause the trench depth and sidewall profile to vary across the chip and across the wafer.
- the first portion 2114 of the deep isolation trench 2112 may be etched to a depth of 100 to 500 nm.
- a conformal layer of polysilicon 2220 is deposited over the silicon substrate 2002 and in FIG. 2D the layer of polysilicon 2220 is anisotropically etched to form sidewalls 2324 on the first portion 2114 of deep isolation trench 2112 .
- the layer of polysilicon 2220 may be deposited with a thickness in the range of 5 nm to 15 nm. In a preferred embodiment the thickness is 7 nm.
- a thin dielectric layer 2218 for example an oxide with a thickness in the range of 3 nm to 9 nm, may be formed in deep isolation trench 2112 under the polysilicon layer 2220 if desired.
- a second active photoresist pattern 2425 is formed over the substrate 2002 with openings 2427 over the areas where shallow isolation trenches are to be formed. Silicon nitride layer 2006 and pad oxide layer 2004 , which form a hardmask, are etched in the patterned shallow trench openings 2427 . The second active photoresist pattern 2428 is then removed prior to the second trench etch.
- Shallow isolation trench 2529 and the second portion 2528 of deep high voltage trench 2112 are etched together as shown in FIG. 2F .
- the shallow trench 2529 may be etched to a depth of 100 to 500 nm and the depth of the deep trench 2112 may be increased to a depth of 200 nm to 1000 nm.
- the polysilicon sidewall 2324 and liner dielectric 2218 (if present) may be removed.
- FIG. 2G shows a view of the semiconductor device 2000 after a dielectric liner 2636 has been thermally grown or deposited in trenches 2529 and 2112 and the trenches 2529 and 2112 then filled with a dielectric 2638 .
- the dielectric 2638 is then planarized and the silicon nitride layer 2006 and pad oxide layer 2004 removed as shown in FIG. 2H .
- Additional processing to form devices and interconnection may then be performed to complete the integrated circuit.
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- Engineering & Computer Science (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Power Engineering (AREA)
- Physics & Mathematics (AREA)
- Condensed Matter Physics & Semiconductors (AREA)
- General Physics & Mathematics (AREA)
- Computer Hardware Design (AREA)
- Manufacturing & Machinery (AREA)
- Ceramic Engineering (AREA)
- Element Separation (AREA)
Abstract
An isolation trench in a substrate of a semiconductor device includes a first shallow portion, a transition region, and a second deeper portion. The isolation trench contains a dielectric filler. The isolation trench is formed by first forming a first shallow portion of the isolation trench, forming polysilicon sidewalls on the first shallow portion, and then etching the second deeper portion.
Description
- This application is a divisional of U.S. Nonprovisional application Ser. No. 13/284,241, filed Oct. 28, 2011, which claims the benefit of priority of U.S. Provisional Application No. 61/407,756, filed Oct. 28, 2010, both of which are herein incorporated by reference in their entireties.
- The following co-pending patent application is related and hereby incorporated by reference: U.S. patent application Ser. No. 13/284,181 (Texas Instruments docket number TI-66906), filed on Oct. 28, 2011. With its mention in this section, this patent application is not admitted to be prior art with respect to the present invention
- This invention relates to the field of semiconductor devices. More particularly, this invention relates to trench isolation in semiconductor devices.
- As the dimensions of integrated circuits continue to scale to smaller an smaller dimensions, the electrical isolation of one transistor from the next becomes increasingly difficult. The most commonly used method for electrical isolation is shallow trench isolation (STI) in which shallow trenches are formed between transistors and filled with a dielectric. In instances where the voltage is higher, the trenches must either be made wider or deeper to support the higher voltage. Increasing the active pitch (trench opening width plus active geometry width) by making the trenches wider is the more manufacturable solution, but it also causes the area of the integrated circuit to increase thus reducing the number of chips that may be formed on a wafer with a resultant increase in cost per chip. Making the trenches deeper while keeping the active pitch constant is difficult because trench etch tends to increase the width of the trench opening for deeper trenches. This results in a decrease in the width of the active width resulting in reduced transistor drive current.
- The following presents a simplified summary in order to provide a basic understanding of one or more aspects of the invention. This summary is not an extensive overview of the invention, and is neither intended to identify key or critical elements of the invention, nor to delineate the scope thereof. Rather, the primary purpose of the summary is to present some concepts of the invention in a simplified form as a prelude to a more detailed description that is presented later.
- In one embodiment, an isolation trench in a substrate of a semiconductor device has a shallower portion and a deeper portion and a transition region between the deeper portion and the shallower portion. A slope of a sidewall of the transition region sidewall is less vertical than a slope of a sidewall of the shallower portion and is less vertical than a slope of a sidewall of the deeper portion. The isolation trench contains a dielectric fill material.
- In another embodiment, the isolation trench is formed by forming a first portion of the isolation trench in a substrate of the semiconductor device; forming polysilicon sidewalls on walls of the first portion; etching the substrate below the first portion to form a second portion of the isolation trench; and filling the isolation trench with a dielectric fill material.
-
FIG. 1A through 1H are illustrations of steps in the fabrication of a semiconductor device formed according to a first embodiment. -
FIG. 2A through 2H are illustrations of steps in the fabrication of a semiconductor device formed according to a second embodiment. - The present invention is described with reference to the attached figures, wherein like reference numerals are used throughout the figures to designate similar or equivalent elements. The figures are not drawn to scale and they are provided merely to illustrate the invention. Several aspects of the invention are described below with reference to example applications for illustration. It should be understood that numerous specific details, relationships, and methods are set forth to provide an understanding of the invention. One skilled in the relevant art, however, will readily recognize that the invention can be practiced without one or more of the specific details or with other methods. In other instances, well-known structures or operations are not shown in detail to avoid obscuring the invention. The present invention is not limited by the illustrated ordering of acts or events, as some acts may occur in different orders and/or concurrently with other acts or events. Furthermore, not all illustrated acts or events are required to implement a methodology in accordance with the present invention.
- A method of forming an isolation trench with increased depth without increasing active pitch according to an embodiment is described in
FIGS. 1A through 1H . -
FIG. 1A shows asemiconductor device 1000 having asemiconductor substrate 1002 upon which apad oxide 1004 is grown and asilicon nitride film 1006 is deposited. An activephoto resist pattern 1008 is formed onsubstrate 1002.Photo resist pattern 1008 hasopenings 1010 in which isolation trenches are to be formed. -
FIG. 1B showssemiconductor device 1000 after thesilicon nitride film 1006 and thepad oxide layer 1004 are etched andisolation trench 1112 is partially etched intosubstrate 1002. A first portion ofisolation trench 1112 may be etched to a depth of 100 to 500 nm. Etching a minimum width trench deeper may result in erosion of the top of the trench opening causing the top of thetrench 1114 to widen and theactive width 1116 to become narrower. If theactive width 1116 is a transistor channel this will decrease the transistor width with a resulting decrease in transistor drive current which is undesirable. - To prevent erosion of the top of the
trench 1112 which would increase the size of the trench opening, a layer ofpolysilicon 1220 is deposited over the partially etched trench as shown inFIG. 1C and then etched to formsidewalls 1324 as shown inFIG. 1D . Prior to the polysilicon deposition, athin pad dielectric 1218 may optionally be deposited or grown on the surface oftrench 1112. The thin pad dielectric 1218 may be an oxide that is 3 to 9 nm thick and the layer ofpolysilicon 1220 may be 5 to 15 nm thick. - The
trench 1112 is then etched to full depth which may be 200 to 1000 nm deep as shown inFIG. 1E . Thepolysilicon sidewalls 1324 protect the sidewalls of theupper portion 1426 of thetrench 1112 from erosion while thelower portion 1428 of thetrench 1112 is being etched. Since trench etch is a silicon etch, the polysilicon sidewalls may be partially consumed during the etch of thelower portion 1428 of thetrench 1112. During the lower portion etch approximately 5 nm of the polysilicon sidewall may be etched. Optionally, the thickness of thepolysilicon sidewall 1324 may be optimized so that it is completely consumed during etch of the lower portion of the trench. - The
trench 1112 is shown inFIG. 1F after thepolysilicon sidewall 1324 and pad oxide 1218 (if present) are removed. If the polysilicon sidewall thickness is completely consumed during the etch of thelower portion 1428 of thetrench 1112 the step of removing the polysilicon sidewall is omitted. Thelower portion 1428 of thetrench 1112 which was etched with the polysilicon sidewalls in place may have a morevertical sidewall slope 1534 than thesidewall slope 1530 of theupper portion 1426 of thetrench 1112. There also may be ashort transition region 1532 between theupper portion 1426 of thetrench 1112 which was etched prior to formation of the polysilicon sidewalls and thelower portion 1428 of thetrench 1112 that was etched after formation of the polysilicon sidewalls. How pronounced thetransition region 1532 appears may be determined by the width of thepolysilicon sidewalls 1324. The slope of the sidewall of thetransition region 1532 is less vertical theslope 1534 or theslope 1530. - After the
polysilicon sidewalls 1324 are removed, thetrench 1112 is filled with dielectric 1638 and the dielectric is planarized as shown inFIGS. 1G and 1H using commonly used procedures. The trench may be first lined with a dielectric 1636 such as oxide or oxide plus nitride or a nitrided oxide. The liner dielectric may be thermally grown or deposited using a CVD process for example. The trench may then be filled with a dielectric 1638 such as sub atmospheric chemical vapor deposition (SACVD) oxide, high density plasma (HDP) oxide or high aspect ratio (HARP) oxide as shown inFIG. 1G . -
FIG. 1H shows theintegrated circuit 1000 after planarization by chemical mechanical polishing (CMP) and removal of thesilicon nitride film 1006 and thepad oxide layer 1004. - Additional processing then may be performed to build transistors and other electrical devices and also to build the interconnection layers to complete the integrated circuit.
- In some applications it may be desirable to form deep trenches on portions of the chip where high voltage circuits are constructed and to form shallow trenches where low voltage circuits are constructed. One embodiment in which both deep and shallow isolation trenches are simultaneously formed is illustrated in
FIGS. 2A through 2G . - In
FIG. 2A ,pad oxide 2004 is grown andsilicon nitride film 2006 is deposited onsilicon substrate 2002 ofsemiconductor device 2000. A firstactive photoresist pattern 2008 is then formed oversilicon substrate 2002 withopenings 2010 where the deep isolation trenches which may be used to isolate high voltage devices are to be formed. - A
first portion 2114 ofdeep isolation trench 2112 is etched andactive photoresist pattern 2008 is removed as shown inFIG. 2B . The photo resistpattern 2008 may be removed prior to or post trench etch. It is preferred to remove thepattern 2008 after thesilicon nitride layer 2006 andpad oxide layer 2004 have been etched and before thesilicon substrate 2002 is etched to reduce etch microloading effects which may cause the trench depth and sidewall profile to vary across the chip and across the wafer. Thefirst portion 2114 of thedeep isolation trench 2112 may be etched to a depth of 100 to 500 nm. - In
FIG. 2C , a conformal layer ofpolysilicon 2220 is deposited over thesilicon substrate 2002 and inFIG. 2D the layer ofpolysilicon 2220 is anisotropically etched to form sidewalls 2324 on thefirst portion 2114 ofdeep isolation trench 2112. The layer ofpolysilicon 2220 may be deposited with a thickness in the range of 5 nm to 15 nm. In a preferred embodiment the thickness is 7 nm. Athin dielectric layer 2218, for example an oxide with a thickness in the range of 3 nm to 9 nm, may be formed indeep isolation trench 2112 under thepolysilicon layer 2220 if desired. - In
FIG. 2E a secondactive photoresist pattern 2425 is formed over thesubstrate 2002 withopenings 2427 over the areas where shallow isolation trenches are to be formed.Silicon nitride layer 2006 andpad oxide layer 2004, which form a hardmask, are etched in the patternedshallow trench openings 2427. The second active photoresist pattern 2428 is then removed prior to the second trench etch. -
Shallow isolation trench 2529 and thesecond portion 2528 of deephigh voltage trench 2112 are etched together as shown inFIG. 2F . Theshallow trench 2529 may be etched to a depth of 100 to 500 nm and the depth of thedeep trench 2112 may be increased to a depth of 200 nm to 1000 nm. After the second trench etch thepolysilicon sidewall 2324 and liner dielectric 2218 (if present) may be removed. -
FIG. 2G shows a view of thesemiconductor device 2000 after adielectric liner 2636 has been thermally grown or deposited intrenches trenches - The dielectric 2638 is then planarized and the
silicon nitride layer 2006 andpad oxide layer 2004 removed as shown inFIG. 2H . - Additional processing to form devices and interconnection may then be performed to complete the integrated circuit.
- While various embodiments of the present invention have been described above, it should be understood that they have been presented by way of example only and not limitation. Numerous changes to the disclosed embodiments can be made in accordance with the disclosure herein without departing from the spirit or scope of the invention. Thus, the breadth and scope of the present invention should not be limited by any of the above described embodiments. Rather, the scope of the invention should be defined in accordance with the following claims and their equivalents.
Claims (8)
1. A semiconductor device, comprising:
a substrate;
an isolation trench in said substrate having a shallower portion and a deeper portion and a transition region between said deeper portion and said shallower portion, wherein a first slope of a first sidewall of said transition region sidewall is less vertical than a second slope of a second sidewall of said shallower portion and is less vertical than a third slope of a third sidewall of said deeper portion and said second slope is less vertical than said third slope, said isolation trench containing a dielectric fill material.
2. The semiconductor device of claim 1 wherein a depth of said shallow portion is in the range of 100 to 500 nm.
3. The semiconductor device of claim 1 wherein a depth of said deeper portion is in the range of 100 nm to 500 nm.
4. The semiconductor device of claim 1 wherein a depth of said isolation trench is in the range of 200 nm to 1000 nm.
5. A semiconductor device, comprising:
a substrate;
an isolation trench in said substrate having a shallower portion and a deeper portion and a transition region between said deeper portion and said shallower portion, wherein a first slope of a first sidewall of said shallower portion and is less vertical than a second slope of a second sidewall of said deeper portion, said isolation trench containing a dielectric fill material.
6. The semiconductor device of claim 5 wherein a depth of said shallow portion is in the range of 100 to 500 nm.
7. The semiconductor device of claim 5 wherein a depth of said deeper portion is in the range of 100 nm to 500 nm.
8. The semiconductor device of claim 5 wherein a depth of said isolation trench is in the range of 200 nm to 1000 nm.
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US14/190,229 US20140175597A1 (en) | 2010-10-28 | 2014-02-26 | Trench with reduced silicon loss |
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US40775610P | 2010-10-28 | 2010-10-28 | |
US13/284,241 US8691661B2 (en) | 2010-10-28 | 2011-10-28 | Trench with reduced silicon loss |
US14/190,229 US20140175597A1 (en) | 2010-10-28 | 2014-02-26 | Trench with reduced silicon loss |
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US13/284,241 Division US8691661B2 (en) | 2010-10-28 | 2011-10-28 | Trench with reduced silicon loss |
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US14/190,229 Abandoned US20140175597A1 (en) | 2010-10-28 | 2014-02-26 | Trench with reduced silicon loss |
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JP2014038952A (en) * | 2012-08-17 | 2014-02-27 | Fujitsu Semiconductor Ltd | Semiconductor device manufacturing method |
TWI550766B (en) * | 2014-07-01 | 2016-09-21 | 聯詠科技股份有限公司 | Integrated circuit of driving device and manufacture method thereof |
US9847246B1 (en) * | 2016-09-30 | 2017-12-19 | International Business Machines Corporation | Multiple finFET formation with epitaxy separation |
US10170517B2 (en) * | 2016-12-13 | 2019-01-01 | Taiwan Semiconductor Manufacturing Co., Ltd. | Method for forming image sensor device |
US10043841B1 (en) * | 2017-07-31 | 2018-08-07 | Taiwan Semiconductor Manufacturing Co., Ltd. | Image sensor device and method for forming the same |
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US20070254453A1 (en) * | 2006-04-30 | 2007-11-01 | Semiconductor Manufacturing International (Shanghai) Corporation | Method of Improving a Shallow Trench Isolation Gapfill Process |
US7736991B2 (en) * | 2006-10-31 | 2010-06-15 | Hynix Semiconductor Inc. | Method of forming isolation layer of semiconductor device |
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US5895253A (en) * | 1997-08-22 | 1999-04-20 | Micron Technology, Inc. | Trench isolation for CMOS devices |
US6207532B1 (en) * | 1999-09-30 | 2001-03-27 | Taiwan Semiconductor Manufacturing Company | STI process for improving isolation for deep sub-micron application |
US7354812B2 (en) * | 2004-09-01 | 2008-04-08 | Micron Technology, Inc. | Multiple-depth STI trenches in integrated circuit fabrication |
US7691722B2 (en) * | 2006-03-14 | 2010-04-06 | Micron Technology, Inc. | Isolation trench fill using oxide liner and nitride etch back technique with dual trench depth capability |
US20070238251A1 (en) * | 2006-04-05 | 2007-10-11 | M-Mos Semiconductor Sdn. Bhd. | Method of forming sub-100nm narrow trenches in semiconductor substrates |
-
2011
- 2011-10-28 US US13/284,241 patent/US8691661B2/en active Active
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2014
- 2014-02-26 US US14/190,229 patent/US20140175597A1/en not_active Abandoned
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US7078286B1 (en) * | 2002-09-06 | 2006-07-18 | Lattice Semiconductor Corporation | Process for fabricating a semiconductor device having electrically isolated low voltage and high voltage regions |
US20070254453A1 (en) * | 2006-04-30 | 2007-11-01 | Semiconductor Manufacturing International (Shanghai) Corporation | Method of Improving a Shallow Trench Isolation Gapfill Process |
US7736991B2 (en) * | 2006-10-31 | 2010-06-15 | Hynix Semiconductor Inc. | Method of forming isolation layer of semiconductor device |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
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US20210367044A1 (en) * | 2019-02-08 | 2021-11-25 | Texas Instruments Incorporated | Transistor with field plate over tapered trench isolation |
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US8691661B2 (en) | 2014-04-08 |
US20120104540A1 (en) | 2012-05-03 |
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