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Patent US4946735A successfully refreshed from Google Patents.
US4946735A
Expired / Lapsed
US
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Ultra-thin semiconductor membranes
Assignee: Cornell Research Foundation Inc
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Filing: 1988-12-14
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Granted: 1990-08-07
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Expires: 2008-12-14
Abstract
Abstract This invention relates to ultra-thin semiconductor films which can be in the submicron range formed from semiconductor materials such as silicon, germanium and gallium aresenide. The films are formed by creating a thin slightly damaged surface on the polished reverse side of a film (e.g., a wafer) of the semiconductor by low dose ion implantation and then etching the semiconductor material on the front side of the film to remove the semiconductor material down to the ion implanted damaged layer. While the implanted ions can be chosen from functionally desirable ions which upon annealing remain in the film to alter the original electrical characteristics, the implanted ions can also be chosen so that upon annealing, the resultant ultra-thin semiconductor film has the same electrical characteristics as the original semiconductor material. The ion implantation changes the etching characteristics of the ion implanted layer. Thus, when the partially damaged semiconductor material is exposed to an etchant the etching rate in the damaged region is decreased by a factor of several thousand as compared to the undamag GOVERNMENT FUNDING The invention described and claimed herein was at least in part supported by the National Submicron Facility under NSF Grant #ECS-8200312 to the NRRFSS.
Inventors
- 👤 Kevin C. Lee
- 👤 Charles A. Lee
- 👤 John Silcox
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:53
CPC Classifications
H; H10; H10P; H10P95/00; H10P95/90; H10P50/00; H10P50/20; H10P50/60; H10P50/61; H10P50/613; H10P50/617; H10P52/00; H10P95/70; H10P95/904; Y; Y10; Y10S; Y10S148/00; Y10S148/003; Y10S148/005; Y10S148/042; Y10S148/056; Y10S148/058; Y10S148/064; Y10S148/065; Y10S148/083; Y10S148/119; Y10S148/135; Y10S148/90; Y10S438/00; Y10S438/914; Y10S438/924; Y10S438/977; Y10T; Y10T428/00; Y10T428/26; Y10T428/261; Y10T428/266; Y10T428/31; Y10T428/315
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
147 words
A method for forming ultra thin semiconductor material films which comprises: (a) implanting ions on the reverse side of a semiconductor material film to a predetermined depth of two microns or less, which is a depth less than the thickness of the film, in an amount sufficient to cause a damaged layer in the crystalline structure with damage sufficient to create a significant differential etching dissolution rate between the damaged layer and the remainder of the semiconductor material, (b) etching the front side of the semiconductor material by an anodic etching process to remove at least a portion of the undamaged portion of the semiconductor material to expose the damaged layer, (c) annealing the resultant exposed damaged layer at a temperature and for a time sufficient to heal the ion implantation damage to thereby provide a thin film of semiconductor material less than two microns in thickness.
Claim 2
Independent Claim
147 words
A method for forming ultra thin semiconductor material films which comprises: (a) implanting ions on the reverse side of a semiconductor material film to a predetermined depth of two microns or less, which is a depth less than the thickness of the film, in an amount sufficient to cause a damaged layer in the crystalline structure with damage sufficient to create a significant differential etching dissolution rate between the damaged layer and the remainder of the semiconductor material, (b) etching the front side of the semiconductor material by an anodic etching process to remove at least a portion of the undamaged portion of the semiconductor material to expose the damaged layer, (c) annealing the resultant exposed damaged layer at a temperature and for a time sufficient to heal the ion implantation damage to thereby provide a thin film of semiconductor material less than two microns in thickness.
Claim 3
Dependent Claim
12 words
A method as in claim 1 where the semiconductor material is silicon.
Claim 4
Dependent Claim
34 words
A method as in claim 1 wherein the semiconductor material is silicon or germanium and where the ions are selected from Groups III and V of the Periodic Table, an inert gas or hydrogen.
Claim 5
Dependent Claim
34 words
A method as in claim 1 wherein the semiconductor material is gallium arsenide and where the ions are selected from Groups II, IV or VI of the Periodic Table, an inert gas or hydrogen.
Claim 6
Dependent Claim
22 words
A method as in claim 1 wherein the semiconductor material is selected from the group consisting of silicon, germanium and gallium arsenide.
Claim 7
Independent Claim
21 words
The method as in claims 1 or 5 wherein the resultant thin film has a thickness of less than 1500 Å.
Claim 8
Dependent Claim
30 words
A thin annealed unsupported gallium arsenide monocrystalline semiconductor material having a thickness of less than one micron, doped with ions selected from group II and IV of the Periodic Table.
Claim 9
Dependent Claim
30 words
A thin annealed unsupported gallium arsenide monocrystalline semiconductor material having a thickness of less than one micron, doped with ions selected from group II and IV of the Periodic Table.
Claim 10
Dependent Claim
17 words
A thin annealed germanium monocrystalline etching process-produced semiconductor material having a thickness of less than one micron.
Claim 11
Dependent Claim
17 words
A thin annealed germanium monocrystalline etching process-produced semiconductor material having a thickness of less than one micron.
Claim 12
Dependent Claim
16 words
The thin semiconductor material of claims 7 or 8, having a thickness of less than 1500Å.
Claim 13
Dependent Claim
58 words
A thin annealed undoped monocrystalline etching process-produced semiconductor material selected from the group consisting of silicon, gallium arsenide, germanium, indium arsenide, AlN, GaN, InN, ZnS, CdS, AlP, GaP, InP, ZnSe, CdSe, AlAs, ZnTe, CeTe, AlSb, GaSb, InSb, InAs x P 1-x , Ga x In 1-x As y P 1-y having a thickness of less than one micron.
Claim 14
Dependent Claim
58 words
A thin annealed undoped monocrystalline etching process-produced semiconductor material selected from the group consisting of silicon, gallium arsenide, germanium, indium arsenide, AlN, GaN, InN, ZnS, CdS, AlP, GaP, InP, ZnSe, CdSe, AlAs, ZnTe, CeTe, AlSb, GaSb, InSb, InAs x P 1-x , Ga x In 1-x As y P 1-y having a thickness of less than one micron.
Claim 15
Dependent Claim
47 words
A thin annealed unsupported monocrystalline semiconductor material doped with ions selected from Group II, IV or V of the Periodic Table having a thickness less than one micron and having the same electrical characteristic as the original doped semiconductor material used to create the thin semiconductor material.
Claim 16
Dependent Claim
47 words
A thin annealed unsupported monocrystalline semiconductor material doped with ions selected from Group II, IV or V of the Periodic Table having a thickness less than one micron and having the same electrical characteristic as the original doped semiconductor material used to create the thin semiconductor material.
Claim 17
Dependent Claim
54 words
A thin annealed unsupported monocrystalline undoped semiconductor material or a semiconductor material doped with ions selected from Groups II, IV or V of the Periodic Table having a thickness of less than 1500Å and having the same electrical characteristics as the original undoped or doped semiconductor material used to create the thin semiconductor material.
Claim 18
Dependent Claim
54 words
A thin annealed unsupported monocrystalline undoped semiconductor material or a semiconductor material doped with ions selected from Groups II, IV or V of the Periodic Table having a thickness of less than 1500Å and having the same electrical characteristics as the original undoped or doped semiconductor material used to create the thin semiconductor material.
Claim 19
Dependent Claim
27 words
A thin annealed unsupported monocrystalline semiconductor material having a thickness of less than one micron and doped with ions selected from Group V of the Periodic Table.
Claim 20
Dependent Claim
27 words
A thin annealed unsupported monocrystalline semiconductor material having a thickness of less than one micron and doped with ions selected from Group V of the Periodic Table.
Claim 21
Dependent Claim
21 words
A thin annealed monocrystalline semiconductor film comprising gallium arsenide having a thickness of less than one micron, doped with donor ions.
Claim 22
Dependent Claim
21 words
A thin annealed monocrystalline semiconductor film comprising gallium arsenide having a thickness of less than one micron, doped with donor ions.
Claim 23
Dependent Claim
31 words
A thin annealed unsupported monocrystalline semiconductor film comprising a material selected from the group consisting of silicon and germanium having a thickness of less than one micron doped with donor ions.
Claim 24
Dependent Claim
31 words
A thin annealed unsupported monocrystalline semiconductor film comprising a material selected from the group consisting of silicon and germanium having a thickness of less than one micron doped with donor ions.
Claim 25
Dependent Claim
58 words
A thin annealed monocrystalline etching process-produced semiconductor material comprising a material selected from the group consisting of indium arsenide, AlN, GaN, InN, ZnS, CdS, AlP, GaP, InP, ZnSe, CdSe, AlAs, ZnTe, CdTe, AlSb, GaSb, InSb, InAs x P 1-x' Ga x In 1-X As y P 1-y' and doped diamond, having a thickness of less than two microns.
Claim 26
Dependent Claim
58 words
A thin annealed monocrystalline etching process-produced semiconductor material comprising a material selected from the group consisting of indium arsenide, AlN, GaN, InN, ZnS, CdS, AlP, GaP, InP, ZnSe, CdSe, AlAs, ZnTe, CdTe, AlSb, GaSb, InSb, InAs x P 1-x' Ga x In 1-X As y P 1-y' and doped diamond, having a thickness of less than two microns.
Claim 27
Dependent Claim
31 words
A thin annealed monocrystalline semiconductor material as in claim 16 wherein the thin semiconductor material has the same electrical characteristics as the semiconductor material used to create the thin semiconductor material.
Claim 28
Dependent Claim
19 words
The thin annealed monocrystalline semiconductor material of claims 16 or 17 having a thickness of less than one micron.
Claim 29
Dependent Claim
60 words
A thin unsupported annealed undoped monocrystalline semiconductor material selected from the group consisting of silicon, allium arsenide, germanium, indium arsenide, AlA, GaN, InW, ZnS, CdS, AlP, GaP, InP, ZnSe, CdSe, AlAs, ZnTe, CdTe, AlSb, GaSb, InSb, InAs x P 1-x , Ga x In 1-x As y P 1-y , and doped diamond, having a thickness of less than 1500Å.
Claim 30
Dependent Claim
60 words
A thin unsupported annealed undoped monocrystalline semiconductor material selected from the group consisting of silicon, allium arsenide, germanium, indium arsenide, AlA, GaN, InW, ZnS, CdS, AlP, GaP, InP, ZnSe, CdSe, AlAs, ZnTe, CdTe, AlSb, GaSb, InSb, InAs x P 1-x , Ga x In 1-x As y P 1-y , and doped diamond, having a thickness of less than 1500Å.
Claim 31
Dependent Claim
25 words
The thin annealed monocrystalline semiconductor material of claims 7, 8, 10, 11, 14, 15, 16, 17 or 19 having a thickness of less than 1500Å.
Claim 32
Dependent Claim
17 words
A thin annealed unsupported monocrystaline semiconductor material comprising gallium arsenide having a thickness of less than 1500Å.
Claim 33
Dependent Claim
17 words
A thin annealed unsupported monocrystaline semiconductor material comprising gallium arsenide having a thickness of less than 1500Å.
Claim 34
Dependent Claim
63 words
A thin annealed monocrystalline unsupported undoped semiconductor material or an unsupported semiconductor material doped with ions selected from groups II, IV or V of the Periodic Table having a thickness of less than one micron and having the same electrical characteristics as the original undoped or doped semiconductor material used to create the thin semiconductor material used to create the thin semiconductor material.
Claim 35
Dependent Claim
63 words
A thin annealed monocrystalline unsupported undoped semiconductor material or an unsupported semiconductor material doped with ions selected from groups II, IV or V of the Periodic Table having a thickness of less than one micron and having the same electrical characteristics as the original undoped or doped semiconductor material used to create the thin semiconductor material used to create the thin semiconductor material.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-08-06 | 1994-02-05 | 1994-08-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-08-06 | 1998-02-05 | 1998-08-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-08-06 | 2002-02-05 | 2002-08-07 | $7700.00 | Window Closed / Lapsed |