US4931409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of manufacturing semiconductor device having trench isolation
Assignee: Toshiba Corp
•
Filing: 1989-01-30
•
Granted: 1990-06-05
•
Expires: 2009-01-30
Abstract
Abstract A method of manufacturing a semiconductor device comprising steps of forming a trench on a semiconductor substrate, forming a first film on the surface of the semiconductor substrate so as to have a large thickness on an upper portion of a side surface of the trench, and to have a small thickness on a bottom portion of the trench, selectively doping an impurity in the bottom portion of the trench through a thin portion of the first film formed on the bottom portion of the trench to form an impurity region on the bottom portion of the trench, removing the first film, and forming a second film having an insulating property on the surface of the semiconductor substrate. A dielectric material or conductive material layer is formed in the trench in which the second film is formed on the inner surface. When the dielectric material or the conductive material layer is formed in the trench, a method of this invention can be applied to formation of trench isolation. When the conductive material layer is formed in the trench, this method can be applied formation of a trench capacitor.
Inventors
- 👤 Hiroomi Nakajima
- 👤 Nobuyuki Itoh
- 👤 Hiroyuki Nihira
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 05:12
CPC Classifications
H; H10; H10D; H10D1/00; H10D1/01; H10D1/045; H10D1/047; H10W; H10W10/00; H10W10/01; H10W10/041; H10W10/40
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
141 words
A method of manufacturing a semiconductor device, comprising the steps of forming a trench in a semiconductor substrate, forming a first film on the surface of said semiconductor substrate including an inner surface of siad trench so as to have a large thickness on the surface of said semiconductor substrate and on an upper portion of a side surface of said trench and to have a small thickness on a bottom portion of said trench, selectively doping an impurity in the bottom portion of said trench through a thin portion of the first film formed on the bottom portion of said trench to form an impurity region on the bottom portion of said trench, removing said first film, and forming a second film having an insulating property on the surface of said semiconductor substrate including the inner surface of said trench.
Claim 2
Independent Claim
141 words
A method of manufacturing a semiconductor device, comprising the steps of forming a trench in a semiconductor substrate, forming a first film on the surface of said semiconductor substrate including an inner surface of siad trench so as to have a large thickness on the surface of said semiconductor substrate and on an upper portion of a side surface of said trench and to have a small thickness on a bottom portion of said trench, selectively doping an impurity in the bottom portion of said trench through a thin portion of the first film formed on the bottom portion of said trench to form an impurity region on the bottom portion of said trench, removing said first film, and forming a second film having an insulating property on the surface of said semiconductor substrate including the inner surface of said trench.
Claim 3
Dependent Claim
29 words
A method according to claim 1, wherein the step of forming said first film is performed by deposition of SiO 2 by normal pressure CVD or low pressure CVD.
Claim 4
Dependent Claim
35 words
A method according to claim 1, wherein the step of forming said first film is performed by deposition of one member selected from the group consisting of W, Mo, Al and SiO 2 by sputtering.
Claim 5
Dependent Claim
57 words
A method according to claim 1, wherein said second film is selected from the group consisting of a thermal oxide film, a CVD SiO 2 film, a CVD Si 3 N 4 film, a CVD PSG film, a CVD Al 2 O 3 film, a sputtered SiO 2 film and a sputtered Al 2 O 3 film.
Claim 6
Dependent Claim
33 words
A method according to claim 1, further comprising the step of burying a dielectric material or a conductive material in a trench in which said second film is formed on the inner surface.
Claim 7
Dependent Claim
36 words
A method according to claim 5, wherein said dielectric material is one selected from the group consisting of polycrystalline silicon, amorphous silicon Al 2 O 3 , SiO 2 , Si 3 N 4 and PSG.
Claim 8
Dependent Claim
28 words
A method according to claim 5, wherein said conductive material is one selected from the group consisting of polycrystalline silicon containing an impurity, tungsten silicide and molybdenum silicide.
Claim 9
Independent Claim
192 words
A method of manufacturing a semiconductor device, comprising the steps of forming a trench in a semiconductor substrate, forming a first film on the surface of said semiconductor substrate including an inner surface of said trench so as to have a small thickness on an upper corner portion of a side surface of said trench, and to have a large thickness on a bottom corner portion of said trench, etching a surface of said first film to entirely or partially remove said first film, forming a second film on the surface of said semiconductor substrate so as to have a large thickness on an upper portion of the side surface of said trench, and to have a small thickness on a bottom portion of said trench selectively doping an impurity in the bottom portion of said trench through a thin portion of the second film formed on the bottom portion of said trench to form an impurity region in the bottom portion of said trench, removing said second film, and forming a third film having an insulating property on the surface of said semiconductor substrate including the inner surface of said trench.
Claim 10
Independent Claim
192 words
A method of manufacturing a semiconductor device, comprising the steps of forming a trench in a semiconductor substrate, forming a first film on the surface of said semiconductor substrate including an inner surface of said trench so as to have a small thickness on an upper corner portion of a side surface of said trench, and to have a large thickness on a bottom corner portion of said trench, etching a surface of said first film to entirely or partially remove said first film, forming a second film on the surface of said semiconductor substrate so as to have a large thickness on an upper portion of the side surface of said trench, and to have a small thickness on a bottom portion of said trench selectively doping an impurity in the bottom portion of said trench through a thin portion of the second film formed on the bottom portion of said trench to form an impurity region in the bottom portion of said trench, removing said second film, and forming a third film having an insulating property on the surface of said semiconductor substrate including the inner surface of said trench.
Claim 11
Dependent Claim
39 words
A method according to claim 8, wherein the step of forming said first film is performed by deposition of a material selected from the group consisting of polycrystalline silicon, silicon dioxide, Al, W and Mo by CVD or sputtering.
Claim 12
Dependent Claim
29 words
A method according to claim 8, wherein the step of forming said second film is performed by deposition of SiO 2 by normal pressure CVD or low pressure CVD.
Claim 13
Dependent Claim
36 words
A method according to claim 8, wherein the step of forming said second film is performed by deposition of a material selected from the group consisting of SiO 2 , Al, W and Mo by sputtering.
Claim 14
Dependent Claim
57 words
A method according to claim 8, wherein said third film is selected from the group consisting of a thermal oxide film, a CVD SiO 2 film, a CVD Si 3 N 4 film, a CVD PSG film, a CVD Al 2 O 3 film, a sputtered SiO 2 film and a sputtered Al 2 O 3 film.
Claim 15
Dependent Claim
33 words
A method according to claim 8, further comprising the step of burying a dielectric material or a conductive material in a trench in which said third film is formed on the inner surface.
Claim 16
Dependent Claim
35 words
A method according to claim 13, wherein said dielectric material is selected from the group consisting of polycrystalline silicon, amorphous silicon, SiO 2 , Si 3 N 4 , Al 2 O 3 and PSG.
Claim 17
Dependent Claim
27 words
A method according to claim 13, wherein said conductive material is selected from the group consisting of polycrystalline silicon containing an impurity, tungsten silicide, and molybdenum silicide.
Claim 18
Independent Claim
107 words
A method of manufacturing a semiconductor device, comprising the steps of forming a trench on a semiconductor substrate, forming a first film on the surface of said semiconductor substrate including an inner surface of said trench so as to have a small thickness on an upper corner portion of a side surface of said trench, and to have a large thickness on a bottom corner portion of said trench, etching a surface of said first film entirely or partially to remove said first film, and forming a second film having an insulating property on the surface of said semiconductor substrate including the inner surface of said trench.
Claim 19
Independent Claim
107 words
A method of manufacturing a semiconductor device, comprising the steps of forming a trench on a semiconductor substrate, forming a first film on the surface of said semiconductor substrate including an inner surface of said trench so as to have a small thickness on an upper corner portion of a side surface of said trench, and to have a large thickness on a bottom corner portion of said trench, etching a surface of said first film entirely or partially to remove said first film, and forming a second film having an insulating property on the surface of said semiconductor substrate including the inner surface of said trench.
Claim 20
Dependent Claim
37 words
A method according to claim 16, wherein the step of forming said first film is performed by deposition of a material selected from the group consisting of polycrystalline silicon, Al, W and Mo by CVD or sputtering.
Claim 21
Dependent Claim
57 words
A method according to claim 16, wherein said second film is selected from the group consisting of a thermal oxide film, a CVD SiO 2 film, a CVD Si 3 N 4 film, a CVD PSG film, a CVD Al 2 O 3 film, a sputtered SiO 2 film and a sputtered Al 2 O 3 film.
Claim 22
Dependent Claim
33 words
A method according to claim 16, further comprising the step of burying a dielectric material or a conductive material in a trench in which said second film is formed on the inner surface.
References Cited (Backward Citations)
JPS5388584A
Cited
US4471525A
Cited
EP0066042A2
Cited
US4493740A
Cited
US4519128A
Cited
US4534824A
Cited
US4703554A
Cited
US4660278A
Cited
JPS6212660A
Cited
US4766090A
Cited
JPS62298110A
Cited
US4693781A
Cited
JPS6399563A
Cited
JPS63114158A
Cited
JPS63287024A
Cited
GB2207281A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-06-04 | 1993-12-04 | 1994-06-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-06-04 | 1997-12-04 | 1998-06-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-06-04 | 2001-12-04 | 2002-06-05 | $7700.00 | Window Closed / Lapsed |