US4441941A
Expired / Lapsed
US
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Method for manufacturing a semiconductor device employing element isolation using insulating materials
Assignee: Toshiba Corp
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Filing: 1981-03-04
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Granted: 1984-04-10
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Expires: 2001-03-04
Abstract
Abstract A method for element isolation utilizing insulating materials on a semiconductor substrate in which an oxidizable material layer of polycrystalline silicon or the like is formed overlying the substrate surface, the oxidizable material layer disposed at the element-isolation-forming regions is oxidized using an oxidation mask, the oxidation mask is removed and, if necesary at least part of the unoxidized oxidizable material below the mask is removed. Predetermined processes such as oxidation and diffusion are performed thereafter to form semiconductor elements such as MOS transistors and bipolar transistors with high packaging density and reliability.
Inventors
- 👤 Hiroshi Nozawa
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 16:42
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/10; H10W10/17; H10P; H10P14/00; H10P14/60; H10P14/63; H10P14/6302; H10P14/6304; H10P14/6306; H10P14/6308; H10P76/00; H10P76/40; H10W10/01; H10W10/011; H10W10/014; H10W10/0142; Y; Y10; Y10S; Y10S438/00; Y10S438/911
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
129 words
A method for manufacturing a semiconductor device employing element isolation of an active region in a semiconductor substrate by forming insulating materials, said method comprising the steps of: a. forming an oxidizable material layer on a surface of the semiconductor substrate; b. forming an oxidation mask on a portion of said oxidizable material layer overlying said active region; c. oxidizing at least part of said oxidizable material layer not covered with said oxidation mask forming an oxide layer for element isolation; d. removing said oxidation mask; e. partially exposing the surface of said semiconductor substrate by removing at least a part of said oxidizable material layer exposed by said step of removing said oxidation mask; and f. forming a semiconductor element in said exposed surface of said semiconductor substrate.
Claim 2
Independent Claim
129 words
A method for manufacturing a semiconductor device employing element isolation of an active region in a semiconductor substrate by forming insulating materials, said method comprising the steps of: a. forming an oxidizable material layer on a surface of the semiconductor substrate; b. forming an oxidation mask on a portion of said oxidizable material layer overlying said active region; c. oxidizing at least part of said oxidizable material layer not covered with said oxidation mask forming an oxide layer for element isolation; d. removing said oxidation mask; e. partially exposing the surface of said semiconductor substrate by removing at least a part of said oxidizable material layer exposed by said step of removing said oxidation mask; and f. forming a semiconductor element in said exposed surface of said semiconductor substrate.
Claim 3
Dependent Claim
20 words
A method according to claim 1, wherein an oxide layer is interposed between said semiconductor substrate and said oxidizable material.
Claim 4
Dependent Claim
15 words
A method according to claim 1, wherein said oxidation mask is made of silicon nitride.
Claim 5
Dependent Claim
37 words
A method according to claim 1, wherein a step of doping an impurity into an oxide layer-forming region of said semiconductor substrate is performed before the step of oxidizing at least part of said oxidizable material layer.
Claim 6
Dependent Claim
27 words
A method according to claim 2, wherein a photoresist for forming said oxidation mask is used as the doping mask in the step of doping the impurity.
Claim 7
Dependent Claim
20 words
A method according to claim 5, wherein the area of said oxidation mask is smaller than that of said photoresist.
Claim 8
Dependent Claim
39 words
A method according to claim 1, wherein the step of oxidizing at least part of said oxidizable material layer results in forming an oxide layer as an upper layer and forming an unoxidized shield layer as a lower layer.
Claim 9
Independent Claim
18 words
A method according to any one of claims 1-3 and 5-7, wherein said oxidizable material is non-monocrystalline silicon.
Claim 10
Independent Claim
25 words
A method according to any one of claims 1-4 and 5-7, wherein said oxidizable material is a material which oxidizes faster than said semiconductor substrate.
Claim 11
Dependent Claim
38 words
A method according to claim 9, wherein said material which oxidizes faster than said semiconductor substrate is at least one member selected from the group consisting of polycrystalline silicon of high impurity concentration, molybdenum silicide, and tungsten silicide.
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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) | 1987-04-10 | 1987-10-10 | 1988-04-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-04-10 | 1991-10-10 | 1992-04-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-04-10 | 1995-10-10 | 1996-04-10 | $7700.00 | Window Closed / Lapsed |