US4472874A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of forming planar isolation regions having field inversion regions
Assignee: Toshiba Corp
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Filing: 1982-06-03
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Granted: 1984-09-25
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Expires: 2002-06-03
Abstract
Abstract A method for manufacturing integrated circuit devices wherein semiconductor elements are isolated by insulation material comprising the following steps of: (a) providing a mask pattern on a predetermined semiconductor element region of a semiconductor substrate; (b) introducing by first ion-implantation impurities of the same conductivity type as that of the substrate into the substrate using the mask pattern as an ion-implantation mask; (c) etching the substrate and forming a groove using the mask pattern as an etching mask in a manner that part of the impurities remain at least under the mask pattern in the side walls of the groove; (d) introducing by second ion-implantation impurities of the same conductivity type as that of the substrate through the groove into the substrate; (e) burying insulation material in the groove; and (f) forming a semiconductor element on the predetermined semiconductor element region.
Inventors
- 👤 Kei Kurosawa
- 👤 Tadashi Shibata
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:48
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/21; H10D; H10D62/00; H10D62/10; H10D62/102; H10D62/112; H10P30/202; H10P30/204; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0125; H10W10/0126; H10W10/10; H10W10/13
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
92 words
A method of forming planar isolation regions having inversion regions comprising the steps of: (a) providing a mask pattern on a predetermined semiconductor element region of a semiconductor substrate; (b) introducing by ion-implantation impurities of the same conductivity type as that of the substrate into the substrate using the mask pattern as an ion-implantation mask; (c) etching in the ion-implanted substrate directly to form a groove so that part of the impurities remain at least in the side wall of the groove; and (d) burying insulation material in the groove by deposition.
Claim 2
Independent Claim
92 words
A method of forming planar isolation regions having inversion regions comprising the steps of: (a) providing a mask pattern on a predetermined semiconductor element region of a semiconductor substrate; (b) introducing by ion-implantation impurities of the same conductivity type as that of the substrate into the substrate using the mask pattern as an ion-implantation mask; (c) etching in the ion-implanted substrate directly to form a groove so that part of the impurities remain at least in the side wall of the groove; and (d) burying insulation material in the groove by deposition.
Claim 3
Dependent Claim
19 words
The method according to claim 1, wherein the mask pattern is used as the mask for the second ion-implantation.
Claim 4
Dependent Claim
15 words
The method according to claim 1, wherein the groove is formed by reactive ion etching.
Claim 5
Dependent Claim
109 words
The method according to claim 1, wherein the method for burying insulation material in the groove comprises the following steps of: forming a first silicon oxide layer on the semiconductor substrate having a groove by chemical vapor deposition in plasma; etching off the first silicon oxide layer at the periphery of the mask pattern; removing the mask pattern; providing a second silicon oxide layer on the remaining portions of the first silicon oxide layer; providing a melted film on said second silicon oxide layer and solidifying it; etching the solidified film and the new silicon oxide layer in order to leave a flat silicon oxide layer in the groove.
Claim 6
Dependent Claim
36 words
The method according to claim 1, wherein the impurity dose value and the acceleration voltage are changed during the first ion-implantation in order to decrease the impurity concentration according to the depth from the substrate surface.
Claim 7
Dependent Claim
28 words
The method according to claim 1, wherein the first ion-implantation is carried out under the condition that an oxide film exists on the overall surface of the substrate.
Claim 8
Dependent Claim
24 words
The method according to claim 1, wherein the method further includes the step of diffusing the impurities introduced into the substrate after step (b).
Claim 9
Dependent Claim
21 words
The method according to claim 1, wherein the impurity distribution is projected under the predetermined element region through the second ion-implantation.
Claim 10
Dependent Claim
42 words
The method according to claim 1 also including between the steps of etching and burying the step of introducing, by second ion-implantation, impurities of the same conductivity type as that of the substrate directly through surface of the groove into the substrate.
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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) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |