Patent US3290745A successfully refreshed from Google Patents.
US5332445A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aqueous hydrofluoric acid vapor processing of semiconductor wafers
Assignee: Semitool Inc
•
Filing: 1992-09-30
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Granted: 1994-07-26
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Expires: 2012-09-30
Abstract
Abstract Disclosed are methods and apparatuses for improved etching of semiconductor wafers and the like using hydrofluoric acid (HF) and water mixtures or solutions which generate equilibrium vapor mixtures of HF vapor and water vapor which serve as a homogenous etchant gas. The vapor etchants do not employ a carrier gas which will make the vapors nonhomogeneous and reduce etching rates. The vapors are preferably generated from a liquid source which is provided within a contained reaction chamber which holds the wafer. The wafer is preferably oriented with the surface being processed directed downward. The wafer is advantageously positioned above or in close proximity to the equilibrium liquid source of the vapor. The wafer is rotated at a rotational speed in the range of 20-1000 revolutions per minute to provide uniform dispersion of the homogeneous etchant gas across the wafer surface and to facilitate circulation and transfer from the liquid source into etchant gas and onto the processed surface. The liquid source of the vapor can advantageously be provided in a bath immediately below the processed surface of the wafer or in a toroidal basin adjacent to the wafer. The processes provide high speed etching of good uniformity and superior particle count performance.
Inventors
- 👤 Eric J. Bergman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:44
CPC Classifications
H; H10; H10P; H10P72/00; H10P72/04; H10P72/0402; H10P72/0418; H10P72/0422; H10P72/0404; G; G11; G11B; G11B7/00; G11B7/24; G11B7/26
Claims Analysis
Total Claims: 77
Claim 1
Independent Claim
143 words
A process for etching semiconductor wafers using hydrofluoric acid vapor, comprising: containing a wafer within a substantially enclosed processing chamber; producing a vapor mixture of hydrofluoric acid vapor and water vapor to provide a substantially homogeneous etchant gas; said producing a vapor mixture being accomplished by providing a pool of liquid etchant source comprising a substantially homogeneous mixture of hydrofluoric acid and water within the enclosed processing chamber; contacting the substantially homogeneous etchant gas against a processed surface of the wafer which is to be etched; spinning the wafer to provide uniform dispersion of the etchant gas across the wafer surface and to facilitate circulation and transfer of the etchant gas to the processed surface; enhancing production of said vapor mixture from said pool of liquid etchant source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin.
Claim 2
Dependent Claim
143 words
A process for etching semiconductor wafers using hydrofluoric acid vapor, comprising: containing a wafer within a substantially enclosed processing chamber; producing a vapor mixture of hydrofluoric acid vapor and water vapor to provide a substantially homogeneous etchant gas; said producing a vapor mixture being accomplished by providing a pool of liquid etchant source comprising a substantially homogeneous mixture of hydrofluoric acid and water within the enclosed processing chamber; contacting the substantially homogeneous etchant gas against a processed surface of the wafer which is to be etched; spinning the wafer to provide uniform dispersion of the etchant gas across the wafer surface and to facilitate circulation and transfer of the etchant gas to the processed surface; enhancing production of said vapor mixture from said pool of liquid etchant source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin.
Claim 3
Dependent Claim
24 words
A process according to claim 1 wherein said spinning the wafer is at rotational speeds in the approximate range of 20-1000 revolutions per minute.
Claim 4
Dependent Claim
24 words
A process according to claim 1 wherein said spinning the wafer is at rotational speeds in the approximate range of 30-800 revolutions per minute.
Claim 5
Dependent Claim
24 words
A process according to claim 1 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-400 revolutions per minute.
Claim 6
Dependent Claim
24 words
A process according to claim 1 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-250 revolutions per minute.
Claim 7
Dependent Claim
28 words
A process according to claim 1 wherein said spinning the wafer the wafer is accomplished while orienting the processed surface downwardly in proximity to said liquid etchant source.
Claim 8
Dependent Claim
33 words
A process according to claim 6 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid etchant source to portions of the processed surface of the wafer.
Claim 9
Dependent Claim
24 words
A process according to claim 6 wherein said spinning the wafer is at rotational speeds in the approximate range of 20-1000 revolutions per minute.
Claim 10
Dependent Claim
24 words
A process according to claim 6 wherein said spinning the wafer is at rotational speeds in the approximate range of 30-800 revolutions per minute.
Claim 11
Dependent Claim
24 words
A process according to claim 6 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-400 revolutions per minute.
Claim 12
Dependent Claim
24 words
A process according to claim 6 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-250 revolutions per minute.
Claim 13
Dependent Claim
30 words
A process according to claim 6 wherein said liquid etchant source has an approximate molar ratio of hydrofluoric acid to water in the range of 1:100 to 1:1 (hydrofluoric acid:water).
Claim 14
Dependent Claim
30 words
A process according to claim 6 wherein said liquid etchant source has an approximate molar ratio of hydrofluoric acid to water in the range of 1:50 to 1:5 (hydrofluoric acid:water).
Claim 15
Dependent Claim
15 words
A process according to claim 6 wherein said liquid etchant source is recirculated and filtered.
Claim 16
Dependent Claim
40 words
A process according to claim 1 wherein said providing a pool is accomplished by forming said pool beneath a wafer being processed; and further defined by orienting said processed surface downwardly in proximity to the pool of liquid etchant source.
Claim 17
Dependent Claim
33 words
A process according to claim 15 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid etchant source to portions of the processed surface of the wafer.
Claim 18
Dependent Claim
43 words
A process according to claim 1 wherein said providing a pool is accomplished by forming a toroidal pool adjacent to a wafer being processed; and further defined by orienting said processed surface downwardly in proximity to the toroidal pool of liquid etchant source.
Claim 19
Dependent Claim
33 words
A process according to claim 17 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid etchant source to portions of the processed surface of the wafer.
Claim 20
Dependent Claim
143 words
A process for etching semiconductor wafers using vapor, comprising: containing a wafer within a substantially enclosed processing chamber; producing a substantially homogeneous vapor mixture of an etchant vapor and a diluent vapor to provide a substantially homogeneous processing gas; said producing a substantially homogeneous vapor mixture being accomplished by providing a pool of liquid processing fluid source within the substantially enclosed processing chamber; contacting the substantially homogeneous processing gas against a processed surface of the wafer which is to be etched; spinning the wafer to provide uniform dispersion of the substantially homogeneous processing gas across the wafer surface and to facilitate circulation and transfer of the substantially homogeneous processing gas to the processed surface; enhancing production of said vapor mixture from said pool of liquid processing fluid source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin.
Claim 21
Dependent Claim
143 words
A process for etching semiconductor wafers using vapor, comprising: containing a wafer within a substantially enclosed processing chamber; producing a substantially homogeneous vapor mixture of an etchant vapor and a diluent vapor to provide a substantially homogeneous processing gas; said producing a substantially homogeneous vapor mixture being accomplished by providing a pool of liquid processing fluid source within the substantially enclosed processing chamber; contacting the substantially homogeneous processing gas against a processed surface of the wafer which is to be etched; spinning the wafer to provide uniform dispersion of the substantially homogeneous processing gas across the wafer surface and to facilitate circulation and transfer of the substantially homogeneous processing gas to the processed surface; enhancing production of said vapor mixture from said pool of liquid processing fluid source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin.
Claim 22
Dependent Claim
24 words
A process according to claim 19 wherein said spinning the wafer is at rotational speeds in the approximate range of 20-1000 revolutions per minute.
Claim 23
Dependent Claim
24 words
A process according to claim 19 wherein said spinning the wafer is at rotational speeds in the approximate range of 30-800 revolutions per minute.
Claim 24
Dependent Claim
24 words
A process according to claim 19 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-400 revolutions per minute.
Claim 25
Dependent Claim
24 words
A process according to claim 19 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-250 revolutions per minute.
Claim 26
Dependent Claim
28 words
A process according to claim 19 wherein said spinning the wafer the wafer is accomplished with said processed surface downwardly in proximity to said liquid processing fluid source.
Claim 27
Dependent Claim
34 words
A process according to claim 24 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid processing fluid source to portions of the processed surface of the wafer.
Claim 28
Dependent Claim
24 words
A process according to claim 24 wherein said spinning the wafer is at rotational speeds in the approximate range of 20-1000 revolutions per minute.
Claim 29
Dependent Claim
24 words
A process according to claim 24 wherein said spinning the wafer is at rotational speeds in the approximate range of 30-800 revolutions per minute.
Claim 30
Dependent Claim
24 words
A process according to claim 24 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-400 revolutions per minute.
Claim 31
Dependent Claim
24 words
A process according to claim 24 wherein said spinning the wafer is at rotational speeds in the approximate range of 50-250 revolutions per minute.
Claim 32
Dependent Claim
16 words
A process according to claim 24 wherein said liquid processing fluid source is recirculated and filtered.
Claim 33
Dependent Claim
41 words
A process according to claim 19 wherein said providing a pool is accomplished by forming said pool beneath a wafer being processed; and further defined by orienting the processed surface downwardly in proximity to the pool of liquid processing fluid source.
Claim 34
Dependent Claim
34 words
A process according to claim 31 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid processing fluid source to portions of the processed surface of the wafer.
Claim 35
Dependent Claim
44 words
A process according to claim 19 wherein said providing a pool is accomplished by forming a toroidal pool adjacent to a wafer being processed; and further defined by orienting said processed surface downwardly in proximity to the toroidal pool of liquid processing fluid source.
Claim 36
Dependent Claim
34 words
A process according to claim 33 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid processing fluid source to portions of the processed surface of the wafer.
Claim 37
Dependent Claim
17 words
A process according to claim 19 and further comprising agitating the pool of liquid processing fluid source.
Claim 38
Dependent Claim
18 words
A process according to claim 19 and further comprising ultrasonically agitating the pool of liquid processing fluid source.
Claim 39
Dependent Claim
16 words
A process according to claim 19 and further comprising drying the wafer within the processing chamber.
Claim 40
Dependent Claim
16 words
A process according to claim 1 and further comprising agitating the pool of liquid etchant source.
Claim 41
Dependent Claim
17 words
A process according to claim 1 and further comprising ultrasonically agitating the pool of liquid etchant source.
Claim 42
Dependent Claim
16 words
A process according to claim 1 and further comprising drying the wafer within the processing chamber.
Claim 43
Dependent Claim
131 words
A process for vapor processing semiconductor wafers using hydrofluoric acid vapor and water vapor, comprising: containing a wafer within a substantially enclosed processing chamber; providing a substantially homogeneous liquid source comprising a mixture of liquid hydrofluoric acid and liquid water; producing from said liquid source a vapor mixture comprising hydrofluoric acid vapor and water vapor to form a substantially homogeneous reactant gas; contacting the substantially homogeneous reactant gas against a processed surface of the wafer; orienting the processed surface downwardly in proximity to said liquid source; spinning the wafer to provide uniform dispersion of the reactant gas across said processed surface; enhancing production of said vapor mixture from said liquid source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin and against said liquid source.
Claim 44
Dependent Claim
131 words
A process for vapor processing semiconductor wafers using hydrofluoric acid vapor and water vapor, comprising: containing a wafer within a substantially enclosed processing chamber; providing a substantially homogeneous liquid source comprising a mixture of liquid hydrofluoric acid and liquid water; producing from said liquid source a vapor mixture comprising hydrofluoric acid vapor and water vapor to form a substantially homogeneous reactant gas; contacting the substantially homogeneous reactant gas against a processed surface of the wafer; orienting the processed surface downwardly in proximity to said liquid source; spinning the wafer to provide uniform dispersion of the reactant gas across said processed surface; enhancing production of said vapor mixture from said liquid source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin and against said liquid source.
Claim 45
Dependent Claim
32 words
A process according to claim 41 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid source to portions of said processed surface of the wafer.
Claim 46
Dependent Claim
23 words
A process according to claim 41 wherein said spinning the wafer is at speeds in the approximate range of 20-1000 revolutions per minute.
Claim 47
Dependent Claim
23 words
A process according to claim 41 wherein said spinning the wafer is at speeds in the approximate range of 30-800 revolutions per minute.
Claim 48
Dependent Claim
23 words
A process according to claim 41 wherein said spinning the wafer is at speeds in the approximate range of 50-400 revolutions per minute.
Claim 49
Dependent Claim
23 words
A process according to claim 41 wherein said spinning the wafer is at speeds in the approximate range of 50-250 revolutions per minute.
Claim 50
Dependent Claim
31 words
A process according to claim 41 wherein said substantially homogeneous liquid source has an approximate molar ratio of hydrofluoric acid to water in the range of 1:100 to 1:1 (hydrofluoric acid:water).
Claim 51
Dependent Claim
31 words
A process according to claim 41 wherein said substantially homogeneous liquid source has an approximate molar ratio of hydrofluoric acid to water in the range of 1:50 to 1:5 (hydrofluoric acid:water).
Claim 52
Dependent Claim
16 words
A process according to claim 41 wherein said substantially homogeneous liquid source is recirculated and filtered.
Claim 53
Dependent Claim
27 words
A process according to claim 41 wherein said providing a substantially homogeneous liquid source is accomplished by forming a toroidal pool adjacent to a wafer being processed.
Claim 54
Dependent Claim
13 words
A process according to claim 41 and further comprising agitating the liquid source.
Claim 55
Dependent Claim
14 words
A process according to claim 41 and further comprising ultrasonically agitating the liquid source.
Claim 56
Dependent Claim
16 words
A process according to claim 41 and further comprising drying the wafer within the processing chamber.
Claim 57
Dependent Claim
119 words
A process for vapor processing semiconductor wafers using a reactant vapor and a diluent vapor, comprising: containing a wafer within a substantially enclosed processing chamber; providing a substantially homogeneous liquid source comprising a mixture of liquid reactant and liquid diluent; producing from said liquid source a vapor mixture comprising reactant vapor and diluent vapor to form a substantially homogeneous reactant gas; contacting the substantially homogeneous reactant gas against a processed surface of the wafer; spinning the wafer to provide uniform dispersion of the reactant gas across said processed surface; enhancing production of said vapor mixture from said liquid source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin and against the liquid source.
Claim 58
Dependent Claim
119 words
A process for vapor processing semiconductor wafers using a reactant vapor and a diluent vapor, comprising: containing a wafer within a substantially enclosed processing chamber; providing a substantially homogeneous liquid source comprising a mixture of liquid reactant and liquid diluent; producing from said liquid source a vapor mixture comprising reactant vapor and diluent vapor to form a substantially homogeneous reactant gas; contacting the substantially homogeneous reactant gas against a processed surface of the wafer; spinning the wafer to provide uniform dispersion of the reactant gas across said processed surface; enhancing production of said vapor mixture from said liquid source by spinning a member within the enclosed processing chamber to effect circulation of gases therewithin and against the liquid source.
Claim 59
Dependent Claim
32 words
A process according to claim 54 wherein said wafer is positioned within a proximity range of approximately 2-100 millimeters from the liquid source to portions of said processed surface of the wafer.
Claim 60
Dependent Claim
23 words
A process according to claim 54 wherein said spinning the wafer is at speeds in the approximate range of 20-1000 revolutions per minute.
Claim 61
Dependent Claim
23 words
A process according to claim 54 wherein said spinning the wafer is at speeds in the approximate range of 30-800 revolutions per minute.
Claim 62
Dependent Claim
23 words
A process according to claim 54 wherein said spinning the wafer is at speeds in the approximate range of 50-400 revolutions per minute.
Claim 63
Dependent Claim
23 words
A process according to claim 54 wherein said spinning the wafer is at speeds in the approximate range of 50-250 revolutions per minute.
Claim 64
Dependent Claim
16 words
A process according to claim 54 wherein said substantially homogeneous liquid source is recirculated and filtered.
Claim 65
Dependent Claim
27 words
A process according to claim 54 wherein said providing a substantially homogeneous liquid source is accomplished by forming a toroidal pool adjacent to a wafer being processed.
Claim 66
Dependent Claim
16 words
A process according to claim 54 and further comprising agitating the pool of liquid etchant source.
Claim 67
Dependent Claim
17 words
A process according to claim 54 and further comprising ultrasonically agitating the pool of liquid etchant source.
Claim 68
Dependent Claim
16 words
A process according to claim 54 and further comprising drying the wafer within the processing chamber.
Claim 69
Dependent Claim
149 words
A process for vapor processing semiconductor wafers, comprising: supporting a wafer for processing within a substantially enclosed processing chamber; providing liquid source within the substantially enclosed processing chamber to provide a pool of liquid source; said liquid source comprising a substantially homogeneous mixture of liquid hydrofluoric acid and liquid water; producing a substantially homogeneous vapor mixture within the processing chamber from said liquid source; said vapor mixture comprising hydrofluoric acid vapor and water vapor; contacting the vapor mixture against at least one processed surface of the wafer being processed; spinning the wafer in juxtaposition to the pool of liquid source; said wafer being spun at sufficient speeds to mix the vapor mixture and maintain homogeneity thereof and provide uniform dispersion of the vapor mixture across the at least one processed surface of the wafer; enhancing vapor formation by spinning the wafer in juxtaposition to the pool of liquid source.
Claim 70
Dependent Claim
149 words
A process for vapor processing semiconductor wafers, comprising: supporting a wafer for processing within a substantially enclosed processing chamber; providing liquid source within the substantially enclosed processing chamber to provide a pool of liquid source; said liquid source comprising a substantially homogeneous mixture of liquid hydrofluoric acid and liquid water; producing a substantially homogeneous vapor mixture within the processing chamber from said liquid source; said vapor mixture comprising hydrofluoric acid vapor and water vapor; contacting the vapor mixture against at least one processed surface of the wafer being processed; spinning the wafer in juxtaposition to the pool of liquid source; said wafer being spun at sufficient speeds to mix the vapor mixture and maintain homogeneity thereof and provide uniform dispersion of the vapor mixture across the at least one processed surface of the wafer; enhancing vapor formation by spinning the wafer in juxtaposition to the pool of liquid source.
Claim 71
Dependent Claim
41 words
A process according to claim 65 wherein said spinning the wafer in juxtaposition to the pool of liquid source is accomplished with the wafer within a proximity range of approximately 2-100 millimeters from the pool of liquid source to the wafer.
Claim 72
Dependent Claim
58 words
A process according to claim 65 wherein: said spinning the wafer in juxtaposition to the pool of liquid source is accomplished with the wafer within a proximity range of approximately 2-100 millimeters from the pool of liquid source to the wafer; said spinning the wafer is at rotational speeds in the approximate range of 20-1000 revolutions per minute.
Claim 73
Dependent Claim
20 words
A process according to claim 65 and further comprising circulating liquid source through said pool provided in the processing chamber.
Claim 74
Dependent Claim
20 words
A process according to claim 65 and further comprising agitating said pool of liquid source provided in the processing chamber.
Claim 75
Dependent Claim
21 words
A process according to claim 65 and further comprising ultrasonically agitating said pool of liquid source provided in the processing chamber.
Claim 76
Dependent Claim
20 words
A process according to claim 65 and further comprising drying the wafer within the processing chamber while rotating the wafer.
Claim 77
Dependent Claim
20 words
A process according to claim 65 wherein the wafer is rotated in juxtaposition to a toroidal pool of liquid source.
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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) | 1997-07-25 | 1998-01-24 | 1998-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-07-25 | 2002-01-24 | 2002-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-07-25 | 2006-01-24 | 2006-07-26 | $7700.00 | Window Closed / Lapsed |