US5385630A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for increasing sacrificial oxide etch rate to reduce field oxide loss
Assignee: Hewlett Packard Development Co LP
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Filing: 1993-06-29
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Granted: 1995-01-31
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Expires: 2013-06-29
Abstract
Abstract N 2 implantation is used to increase the etch rate of a sacrificial oxide (sometimes referred to as the first gate oxide) in integrated circuitry. This implantation allows etching selectivity by changing the relative etch rates of materials. In the specific implementation described, a field oxide is also provided and this implantation increases the etch rate of the sacrificial oxide relative to that of the field oxide. No heat treatment is applied to the implanted material prior to etching having the ability to repair the damage caused by the bombardment.
Inventors
- 👤 Ara Philipossian
- 👤 Hamid R. Soleimani
- 👤 Brian S. Doyle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:12
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
43 words
In the fabrication of integrated circuitry, the steps of: a) implanting a material on a substrate with nitrogen, to enhance the etchability of said material by an etchant by causing structural damage to said material; and b) exposing said material to said etchant.
Claim 2
Dependent Claim
43 words
In the fabrication of integrated circuitry, the steps of: a) implanting a material on a substrate with nitrogen, to enhance the etchability of said material by an etchant by causing structural damage to said material; and b) exposing said material to said etchant.
Claim 3
Dependent Claim
55 words
The fabrication process of claim 1 wherein said step of implanting causes damage to the atomic structure of said material, further including after said step of implanting but before said step of exposing, the step of maintaining the heat input to said material at less than that at which said damage will be meaningfully repaired.
Claim 4
Dependent Claim
16 words
The fabrication process of claim 1 wherein said implantation species particles are atomic or molecular particles.
Claim 5
Dependent Claim
34 words
The fabrication process of claim 1 wherein said material is silicon dioxide and said implantation is at a dose rate of at least 10 14 per square centimeter of surface of such silicon dioxide.
Claim 6
Dependent Claim
20 words
The fabrication process of claim 4 wherein said material is silicon dioxide formed by growth on a substrate of silicon.
Claim 7
Dependent Claim
21 words
The fabrication process of claim 1 wherein said step of exposing includes exposing said material to a diluent of hydrofluoric acid.
Claim 8
Dependent Claim
29 words
The fabrication process of claim 6 wherein said material is silicon dioxide grown on a substrate of silicon, and there is other silicon dioxide material deposited on said substrate.
Claim 9
Dependent Claim
20 words
The fabrication process of claim 6 wherein said diluent of hydrofluoric acid includes one or more constituents buffering said acid.
Claim 10
Dependent Claim
12 words
The fabrication process of claim 8 wherein said material is silicon dioxide.
Claim 11
Dependent Claim
29 words
In the fabrication of integrated circuitry, the step of tailoring nitrogen implantation of said material with a multitude of implantation conditions to customize the etch rate of said material.
Claim 12
Dependent Claim
29 words
In the fabrication of integrated circuitry, the step of tailoring nitrogen implantation of said material with a multitude of implantation conditions to customize the etch rate of said material.
Claim 13
Dependent Claim
12 words
The fabrication process of claim 10 wherein said material is silicon dioxide.
Claim 14
Dependent Claim
26 words
The fabrication process of claim 11 further including the step of exposing said material after said tailoring to a diluent of hydrofluoric acid as an etchant.
Claim 15
Dependent Claim
21 words
In the fabrication of integrated circuitry, increasing the etch rate of a silicon dioxide layer by implanting nitrogen in the same.
Claim 16
Dependent Claim
21 words
In the fabrication of integrated circuitry, increasing the etch rate of a silicon dioxide layer by implanting nitrogen in the same.
Claim 17
Dependent Claim
32 words
The fabrication process of integrated circuitry of claim 13 further including the step of exposing said silicon dioxide after said implantation to an etchant made up of a diluent of hydrofluoric acid.
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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) | 1998-01-30 | 1998-08-01 | 1999-01-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-01-30 | 2002-08-01 | 2003-01-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-01-30 | 2006-08-01 | 2007-01-31 | $7700.00 | Window Closed / Lapsed |