Patent FR2179044A1 successfully refreshed from Google Patents.
US5423944A
Expired / Lapsed
US
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Method for vapor phase etching of silicon
Assignee: Texas Instruments Inc
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Filing: 1994-03-11
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Granted: 1995-06-13
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Expires: 2014-03-11
Abstract
Abstract A method for etching a silicon wafer (20) by using hydrogen fluoride and water vapor combined with ozone is disclosed. The process does not require additional energy excitation or high pressure.
Inventors
- 👤 Man Wong
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:24
CPC Classifications
H; H10; H10P; H10P90/00; H10P90/12; H10P90/126; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/60; H10P50/64; H10P50/642; Y; Y10; Y10S; Y10S438/00; Y10S438/977
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
55 words
A method for etching a silicon water, comprising the steps of: masking portions of said wafer to provide masked portions and unmasked portions of a wafer surface; combining an hydrogen fluoride and water vapor with ozone: and etching silicon from said unmasked portions of said wafer surface with said combined hydrogen fluoride and ozone vapor.
Claim 2
Independent Claim
55 words
A method for etching a silicon water, comprising the steps of: masking portions of said wafer to provide masked portions and unmasked portions of a wafer surface; combining an hydrogen fluoride and water vapor with ozone: and etching silicon from said unmasked portions of said wafer surface with said combined hydrogen fluoride and ozone vapor.
Claim 3
Dependent Claim
31 words
The method, as set forth in claim 1, further comprising passing an inert gas over an azeotropic solution of hydrogen fluoride and water and producing an hydrogen fluoride and water vapor;
Claim 4
Dependent Claim
21 words
The method, as set forth in claim 1, further comprising the step of drying the wafer surface after the etching step.
Claim 5
Dependent Claim
23 words
The method, as set forth in claim 1, wherein the wafer is subjected to room temperature and low pressure during the etching step.
Claim 6
Dependent Claim
19 words
The method, as set forth in claim 3, wherein the low pressure ranges from 70 torr and 550 torr.
Claim 7
Independent Claim
78 words
A method for etching silicon on a water in a semiconductor manufacturing process, comprising the steps of: masking portions of said wafer to provide masked portions and unmasked portions of a wafer surface; passing an inert gas over a heated azeotropic solution of hydrogen fluoride and water and producing an hydrogen fluoride vapor; combining said hydrogen fluoride vapor with ozone; and etching silicon from said unmasked portions of said wafer surface with said combined vapor at room temperature.
Claim 8
Independent Claim
78 words
A method for etching silicon on a water in a semiconductor manufacturing process, comprising the steps of: masking portions of said wafer to provide masked portions and unmasked portions of a wafer surface; passing an inert gas over a heated azeotropic solution of hydrogen fluoride and water and producing an hydrogen fluoride vapor; combining said hydrogen fluoride vapor with ozone; and etching silicon from said unmasked portions of said wafer surface with said combined vapor at room temperature.
Claim 9
Dependent Claim
29 words
The method, as set forth in claim 6, wherein the inert gas is gaseous nitrogen and it is introduced at a rate of approximately one standard liter per minute.
Claim 10
Dependent Claim
26 words
The method, as set forth in claim 6, wherein the azeotropic solution of hydrogen fluoride and water is composed of approximately 40:60 hydrogen fluoride to water.
Claim 11
Dependent Claim
21 words
The method, as set forth in claim 6, further comprising the step of drying the wafer surface after the etching step.
Claim 12
Dependent Claim
20 words
The method, as set forth in claim 6, wherein said wafer is subjected to low pressure during said etching step.
Claim 13
Dependent Claim
19 words
The method, as set forth in claim 10, wherein the low pressure ranges from 70 torr and 550 torr.
Claim 14
Independent Claim
113 words
A method for etching silicon on a wafer in a reactor, comprising the steps of: masking portions of said wafer to provide masked portions and unmasked portions of a wafer surface; introducing an inert gas into a vaporizer containing a heated azeotropic solution of hydrogen fluoride and water; passing said inert gas over said azeotropic solution and producing an hydrogen fluoride vapor; combining said hydrogen fluoride vapor with ozone; injecting said combined vapor into an etch chamber containing the wafer; etching silicon from said unmasked portions of said wafer surface with said combined vapor to remove crystal defects from said silicon; and rapidly pumping down the etch chamber to dry said wafer surface.
Claim 15
Independent Claim
113 words
A method for etching silicon on a wafer in a reactor, comprising the steps of: masking portions of said wafer to provide masked portions and unmasked portions of a wafer surface; introducing an inert gas into a vaporizer containing a heated azeotropic solution of hydrogen fluoride and water; passing said inert gas over said azeotropic solution and producing an hydrogen fluoride vapor; combining said hydrogen fluoride vapor with ozone; injecting said combined vapor into an etch chamber containing the wafer; etching silicon from said unmasked portions of said wafer surface with said combined vapor to remove crystal defects from said silicon; and rapidly pumping down the etch chamber to dry said wafer surface.
Claim 16
Dependent Claim
29 words
The method, as set forth in claim 12, wherein the inert gas is gaseous nitrogen and it is introduced at a rate of approximately one standard liter per minute.
Claim 17
Dependent Claim
26 words
The method, as set forth in claim 12, wherein the azeotropic solution of hydrogen fluoride and water is composed of approximately 40:60 hydrogen fluoride to water.
Claim 18
Dependent Claim
23 words
The method, as set forth in claim 12, wherein the wafer is subjected to room temperature and low pressure during the etching step.
Claim 19
Dependent Claim
19 words
The method, as set forth in claim 15, wherein the low pressure ranges from 70 torr and 550 torr.
Claim 20
Dependent Claim
39 words
The method, as set forth in claim 12, further comprising the step of introducing oxygen into a remote plasma generator at the rate of four standard liter per minute and producing a resultant gaseous mixture containing approximately 5% ozone.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-06-12 | 1998-12-12 | 1999-06-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-06-12 | 2002-12-12 | 2003-06-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-06-12 | 2006-12-12 | 2007-06-13 | $7700.00 | Window Closed / Lapsed |