US5589422A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Controlled, gas phase process for removal of trace metal contamination and for removal of a semiconductor layer
Assignee: Intel Corp
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Filing: 1993-01-15
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Granted: 1996-12-31
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Expires: 2013-01-15
Abstract
Abstract A ultra-clean, ULSI-supportable process is described for cleaning and etching very thin layers of a semiconductor surface in a gaseous ambient at approximately room temperature. An oxidized surface is etched and cleaned in the vapors of azeotropic, aqueous acids. The cleaning properties of the vapors of the aqueous acids are such that metallic contaminants residing at the surface or within the oxidized layer are complexed and later rinsed away in a rinsing process. The surface is then re-oxidized in an ozone ambient, the resultant oxidation reaction being self-limiting such that the oxide layer is grown to a consistent, predetermined thickness. The process may be repeated any number of times depending on the depth at which any contaminants reside.
Inventors
- 👤 Suresh A. Bhat
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:03
CPC Classifications
H; H10; H10P; H10P70/00; H10P70/10; H10P70/12
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
110 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a gaseous first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein a portion of said semiconductor layer is consumed; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at a temperature within a range of approximately room temperature to 300° C. during and between steps a and b.
Claim 2
Dependent Claim
110 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a gaseous first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein a portion of said semiconductor layer is consumed; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at a temperature within a range of approximately room temperature to 300° C. during and between steps a and b.
Claim 3
Dependent Claim
18 words
The process as defined by claim 1 wherein steps a and b are performed a plurality of times.
Claim 4
Dependent Claim
26 words
The process as defined by claim 2 wherein either of steps a or b is performed at a temperature in the range of approximately 20°-100° C.
Claim 5
Dependent Claim
24 words
The process as defined by claim 1 wherein said second ambient is selected from the group consisting of: HF, HCl, and any combination thereof.
Claim 6
Dependent Claim
26 words
The process as defined by claim 1 wherein any of steps a or b is performed at a temperature in the range of approximately 20°-100° C.
Claim 7
Dependent Claim
22 words
The process as defined by claim 1 wherein metal contaminants existing on said surface upon completion of step b are subsequently removed.
Claim 8
Dependent Claim
21 words
The process as defined by claim 1 wherein said oxidized layer has a thickness in the range of approximately 2-200 Angstroms.
Claim 9
Dependent Claim
103 words
A process for treating a semiconductor layer comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient, said first ambient being oxidizing, to form an oxidized layer; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous, to expose a surface; wherein steps a and b are performed a plurality of times and said semiconductor layer is maintained in an absence of UV radiation and at a temperature within a range of approximately room temperature to 300° C. during and between steps a and b.
Claim 10
Dependent Claim
103 words
A process for treating a semiconductor layer comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient, said first ambient being oxidizing, to form an oxidized layer; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous, to expose a surface; wherein steps a and b are performed a plurality of times and said semiconductor layer is maintained in an absence of UV radiation and at a temperature within a range of approximately room temperature to 300° C. during and between steps a and b.
Claim 11
Dependent Claim
24 words
The process as defined by claim 8 wherein said second ambient is selected from the group consisting of: HF, HCl, and any combination thereof.
Claim 12
Dependent Claim
29 words
The process as defined by claim 9 wherein said second ambient further comprises an inert carrier gas selected from the group consisting of nitrogen, argon, or any combination thereof.
Claim 13
Dependent Claim
20 words
The process as defined by claim 8 wherein any of steps a or b is performed at approximately room temperature.
Claim 14
Dependent Claim
126 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein a portion of said semiconductor layer is consumed; and b) etching at least a portion of said oxidized layer in a second ambient wherein said second ambient is selected from the group consisting of HCl, HF, and any combination thereof, said second ambient being gaseous, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at a temperature within a range of approximately room temperature to 100° C. during and between steps a and b.
Claim 15
Dependent Claim
126 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein a portion of said semiconductor layer is consumed; and b) etching at least a portion of said oxidized layer in a second ambient wherein said second ambient is selected from the group consisting of HCl, HF, and any combination thereof, said second ambient being gaseous, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at a temperature within a range of approximately room temperature to 100° C. during and between steps a and b.
Claim 16
Dependent Claim
30 words
The process as defined by claim 12 wherein said second ambient further comprises an inert carrier gas selected from the group consisting of nitrogen, argon, helium, or any combination thereof.
Claim 17
Dependent Claim
20 words
The process as defined by claim 13 wherein any of steps a or b is performed at approximately room temperature.
Claim 18
Dependent Claim
22 words
The process as defined by claim 14 wherein metal contaminants existing on said surface upon completion of step b are subsequently removed.
Claim 19
Dependent Claim
21 words
The process as defined by claim 15 wherein said metal contaminants are removed by a method comprising rinsing with DI water.
Claim 20
Dependent Claim
57 words
The process as defined by claim 13 wherein said second ambient is generated and maintained by flowing a first flow of said inert carrier gas through a first vaporizer containing an azeotropic mixture comprising HF and water, and by flowing a second flow of said inert carrier gas through a second azeotropic mixture comprising HCL and water.
Claim 21
Dependent Claim
18 words
The process as defined by claim 12 wherein steps a and b are performed a plurality of times.
Claim 22
Dependent Claim
106 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein a portion of said semiconductor layer is consumed; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at a temperature in the range of approximately 20°-100° C. during and between steps a and b.
Claim 23
Dependent Claim
106 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein a portion of said semiconductor layer is consumed; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at a temperature in the range of approximately 20°-100° C. during and between steps a and b.
Claim 24
Dependent Claim
18 words
The process as defined by claim 19 wherein steps a and b are performed a plurality of times.
Claim 25
Dependent Claim
114 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein said oxidized layer has a thickness in the range of approximately 2-200 Angstroms; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous and said oxidized layer being at approximately room temperature, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at approximately room temperature during and between steps a and b.
Claim 26
Dependent Claim
114 words
A process for treating a semiconductor layer to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said semiconductor layer in a first ambient comprising ozone, said first ambient being oxidizing, to form an oxidized layer, wherein said oxidized layer has a thickness in the range of approximately 2-200 Angstroms; and b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous and said oxidized layer being at approximately room temperature, to expose a surface; wherein said semiconductor layer is maintained in an absence of UV radiation and at approximately room temperature during and between steps a and b.
Claim 27
Dependent Claim
18 words
The process as defined by claim 21 wherein steps a and b are performed a plurality of times.
Claim 28
Dependent Claim
148 words
A process for treating a silicon layer or a silicon substrate to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said silicon layer or silicon substrate at approximately room temperature in a first ambient, said first ambient comprising ozone, to form an oxidized layer, wherein a portion of said silicon layer or silicon substrate is consumed; b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous and said second ambient is selected from the group consisting of: HF, HCl, and any combination thereof, to expose a surface; and c) removing metal contaminants from said surface by a method comprising rinsing with DI water; wherein said silicon layer or silicon substrate is maintained in an absence of UV radiation and at approximately room temperature during and between steps a, b, and c.
Claim 29
Dependent Claim
148 words
A process for treating a silicon layer or a silicon substrate to remove contaminants and impurities therein, comprising the steps of: a) oxidizing at least a portion of said silicon layer or silicon substrate at approximately room temperature in a first ambient, said first ambient comprising ozone, to form an oxidized layer, wherein a portion of said silicon layer or silicon substrate is consumed; b) etching at least a portion of said oxidized layer in a second ambient, said second ambient being gaseous and said second ambient is selected from the group consisting of: HF, HCl, and any combination thereof, to expose a surface; and c) removing metal contaminants from said surface by a method comprising rinsing with DI water; wherein said silicon layer or silicon substrate is maintained in an absence of UV radiation and at approximately room temperature during and between steps a, b, and c.
Claim 30
Dependent Claim
18 words
The process as defined by claim 23 wherein steps a or b are performed a plurality of times.
Claim 31
Dependent Claim
30 words
The process as defined by claim 24 wherein said second ambient further comprises an inert carrier gas selected from the group consisting of nitrogen, argon, helium, or any combination thereof.
Claim 32
Dependent Claim
30 words
The process as defined by claim 23 wherein said second ambient further comprises an inert carrier gas selected from the group consisting of nitrogen, argon, helium, or any combination thereof.
Claim 33
Dependent Claim
55 words
The process as defined by claim 26 wherein said second ambient is generated by flowing a first flow of said inert carrier gas through a first vaporizer containing and azeotropic mixture comprising HF and water, and by flowing a second flow or said inert carrier gas through a second azeotropic mixture comprising HCL and water.
Claim 34
Dependent Claim
30 words
The process as defined by claim 27 wherein said inert carrier gas flows through said first and said second vaporizers at a rate in the range of approximately 0.1-20 slm.
Claim 35
Dependent Claim
21 words
The process as defined by claim 23 wherein said oxidized layer has a thickness in the range of approximately 2-200 Angstroms.
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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) | 1999-12-31 | 2000-07-01 | 2000-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-12-31 | 2004-07-01 | 2004-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-12-31 | 2008-07-01 | 2008-12-31 | $7700.00 | Window Closed / Lapsed |