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US5212111A Expired / Lapsed US ⏱️ 0.0 years remaining

Local-oxidation of silicon (LOCOS) process using ceramic barrier layer

Assignee: Micron Technology Inc
•
Filing: 1992-04-22
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Granted: 1993-05-18
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Expires: 2012-04-22
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Abstract

Abstract A local oxidation of silicon (LOCOS) process for semiconductor manufacture in which a barrier layer for the oxidation process and for a subsequent field implant is formed of a ceramic material. The ceramic material is one that can be easily deposited on silicon with low stress and is characterized by an ion stopping power greater than that of silicon nitride. Suitable ceramic materials include metal oxides, titanates, carbides, glasses and ferroelectrics.

Inventors

  • 👤 Trung T. Doan
  • 👤 Gurtej S. Sandhu

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 08:04
CPC Classifications
H; H10; H10P; H10P14/00; H10P14/60; H10P14/61; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0125; H10W10/10; H10W10/13; Y; Y10; Y10S; Y10S148/00; Y10S148/106

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 95 words
A local oxidation of silicon (LOCOS) process for semiconductor manufacture comprising: depositing a low stress barrier layer of a ceramic material having a high ion stopping power on a silicon substrate; patterning and etching the barrier layer to define active areas on the substrate covered with the ceramic material with exposed areas of the substrate therebetween; growing a field oxide in the exposed areas by wet oxidation; implanting the active areas through the field oxide using ions of sufficient energy to penetrate the field oxide but not the barrier layer; and removing the ceramic layer.
Claim 2
Dependent Claim 95 words
A local oxidation of silicon (LOCOS) process for semiconductor manufacture comprising: depositing a low stress barrier layer of a ceramic material having a high ion stopping power on a silicon substrate; patterning and etching the barrier layer to define active areas on the substrate covered with the ceramic material with exposed areas of the substrate therebetween; growing a field oxide in the exposed areas by wet oxidation; implanting the active areas through the field oxide using ions of sufficient energy to penetrate the field oxide but not the barrier layer; and removing the ceramic layer.
Claim 3
Dependent Claim 15 words
The process as recited in claim 1 and wherein: the ceramic material is a titanate.
Claim 4
Dependent Claim 16 words
The process as recited in claim 1 and wherein: the ceramic material is a ferroelectric material.
Claim 5
Dependent Claim 15 words
The process as recited in claim 1 and wherein: the ceramic material is a glass.
Claim 6
Dependent Claim 15 words
The process as recited in claim 1 and wherein: the ceramic material is a carbide.
Claim 7
Dependent Claim 24 words
The process as recited in claim 1 and wherein: consisting of TiO 2 , TaO x , WO x , and ZrO x .
Claim 8
Dependent Claim 19 words
The process as recited in clair: 1 and wherein: the ceramic material is deposited by chemical vapor deposition (CVD).
Claim 9
Dependent Claim 19 words
The process as recited in clair: 1 and wherein: the ceramic material is deposited by chemical vapor deposition (CVD).
Claim 10
Dependent Claim 18 words
The process as recited in claim 1 and wherein: the ceramic material is removed by a wet etch.
Claim 11
Dependent Claim 18 words
The process as recited in claim 1 and wherein: the ceramic material is removed by a dry etch.
Claim 12
Dependent Claim 138 words
A local oxidation of silicon (LOCOS) process for semiconductor manufacture comprising: depositing a barrier layer on a silicon substrate with the barrier layer formed of a ceramic material having a higher ion stopping power than silicon nitride and having a coefficient of thermal expansion that closely matches that of silicon such that it can be deposited with low stress; photopatterning and etching the ceramic barrier layer such that exposed areas are formed on the substrate for a field oxide and active areas on the substrate for active devices are covered with the ceramic barrier layer; growing the field oxide in the exposed areas by wet oxidation; implanting the active areas through the field oxide using ions of sufficient energy to penetrate the field oxide but not the ceramic barrier layer; and removing the ceramic barrier layer by etching.
Claim 13
Dependent Claim 138 words
A local oxidation of silicon (LOCOS) process for semiconductor manufacture comprising: depositing a barrier layer on a silicon substrate with the barrier layer formed of a ceramic material having a higher ion stopping power than silicon nitride and having a coefficient of thermal expansion that closely matches that of silicon such that it can be deposited with low stress; photopatterning and etching the ceramic barrier layer such that exposed areas are formed on the substrate for a field oxide and active areas on the substrate for active devices are covered with the ceramic barrier layer; growing the field oxide in the exposed areas by wet oxidation; implanting the active areas through the field oxide using ions of sufficient energy to penetrate the field oxide but not the ceramic barrier layer; and removing the ceramic barrier layer by etching.
Claim 14
Dependent Claim 31 words
The process as recited in claim 10 and wherein: the ceramic material is selected from the group consisting of a metal oxide, a titanate, a carbide, a glass, or a ferroelectric.
Claim 15
Dependent Claim 23 words
The process as recited in claim 11 and wherein: the ceramic material has an ion stopping power approximately 3X that of silicon nitride.
Claim 16
Dependent Claim 16 words
The process as recited in claim 10 and wherein: the ceramic material is deposited by (CVD).
Claim 17
Dependent Claim 16 words
The process as recited in claim 10 and wherein: the ceramic material is deposited by sputtering.
Claim 18
Dependent Claim 22 words
The process as recited in claim 10 and wherein: the ceramic material is deposited to a thickness of between 500Å to 5000Å.
Claim 19
Dependent Claim 22 words
The process as recited in claim 10 and wherein: the field oxide is grown to a thickness of between 2000Å to 6000Å.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1996-05-17 1996-11-16 1997-05-18 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2000-05-17 2000-11-16 2001-05-18 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2004-05-17 2004-11-16 2005-05-18 $7700.00 Window Closed / Lapsed

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