US5300463A
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Method of selectively etching silicon dioxide dielectric layers on semiconductor wafers
Assignee: Micron Technology Inc
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Filing: 1992-03-06
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Granted: 1994-04-05
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Expires: 2012-03-06
Abstract
Abstract A method of utilizing and etching SiO 2 in the processing of semiconductor wafers comprises: a) providing a layer of undoped SiO 2 atop a wafer; b) providing a layer of doped SiO 2 atop the layer of undoped SiO 2 ; and c) wet etching the layer of doped SiO 2 selectively relative to the undoped layer of SiO 2 utilizing an acid solution, the acid solution comprising a mixture of at least two different mineral acids provided in a selected ratio relative to one another, one of the mineral acids being HF. The preferred volumetric ratio of other mineral acids in the acid solution to HF in the acid solution is from 20:1 to 110:1, with a ratio of from 45:1 to 65:1 being most preferred. Example acids to be combined with the HF include H 2 SO 4 , HCl, HNO 3 , H 3 PO 4 , HBr, HI, HClO 4 , and HIO 4 , or mixtures thereof.
Inventors
- 👤 David A. Cathey
- 👤 J. Brett Rolfson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 03:06
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
131 words
A method of utilizing and etching SiO 2 in the processing of semiconductor wafers, the method comprising the following steps: providing a layer of undoped SiO 2 atop a wafer; providing a layer of doped SiO 2 atop the layer of undoped SiO 2 ; and wet etching the layer of doped SiO 2 selectively relative to the undoped layer of SiO 2 utilizing an acid solution, the acid solution comprising a mixture of at least two different mineral acids provided in a selected ratio relative to one another, one of the mineral acids being HF, the other of the mineral acids being selected from the group consisting of H 2 SO 4 , H 3 PO 4 , HBr, HI, HClO 4 , and HIO 4 , or mixtures thereof.
Claim 2
Independent Claim
131 words
A method of utilizing and etching SiO 2 in the processing of semiconductor wafers, the method comprising the following steps: providing a layer of undoped SiO 2 atop a wafer; providing a layer of doped SiO 2 atop the layer of undoped SiO 2 ; and wet etching the layer of doped SiO 2 selectively relative to the undoped layer of SiO 2 utilizing an acid solution, the acid solution comprising a mixture of at least two different mineral acids provided in a selected ratio relative to one another, one of the mineral acids being HF, the other of the mineral acids being selected from the group consisting of H 2 SO 4 , H 3 PO 4 , HBr, HI, HClO 4 , and HIO 4 , or mixtures thereof.
Claim 3
Dependent Claim
34 words
The method of utilizing and etching SiO 2 of claim 1 wherein the volumetric ratio of other mineral acids in the acid solution to HF in the acid solution is from 20:1 to 110:1.
Claim 4
Dependent Claim
34 words
The method of utilizing and etching SiO 2 of claim 1 wherein the volumetric ratio of other mineral acids in the acid solution to HF in the acid solution is from 45:1 to 65:1.
Claim 5
Dependent Claim
32 words
The method of utilizing and etching SiO 2 of claim 1 wherein the volumetric ratio of other mineral acids in the acid solution to HF in the acid solution is about 55:1.
Claim 6
Dependent Claim
21 words
The method of utilizing and etching SiO 2 of claim 1 wherein the doped layer of SiO 2 comprises borophosphosilicate glass.
Claim 7
Dependent Claim
44 words
The method of utilizing and etching SiO 2 of claim 1 wherein, the volumetric ratio of other mineral acids in the acid solution to HF in the acid solution is from 20:1 to 110:1; and the doped layer of SiO 2 comprises borophosphosilicate glass.
Claim 8
Dependent Claim
44 words
The method of utilizing and etching SiO 2 of claim 1 wherein, the volumetric ratio of other mineral acids in the acid solution to HF in the acid solution is from 45:1 to 65:1; and the doped layer of SiO 2 comprises borophosphosilicate glass.
Claim 9
Independent Claim
113 words
A method of utilizing and etching SiO 2 in the processing of semiconductor wafers, the method comprising the following steps: providing a layer of undoped SiO 2 atop a wafer; providing a layer of doped SiO 2 atop the layer of undoped SiO 2 ; and wet etching the layer of doped SiO 2 selectively relative to the undoped layer of SiO 2 and selectively relative to silicon utilizing an acid solution, the acid solution comprising a mixture of at least two different mineral acids provided in a selected ratio relative to one another, one of the mineral acids being HF, the other of the mineral acids being H 2 SO 4 .
Claim 10
Independent Claim
113 words
A method of utilizing and etching SiO 2 in the processing of semiconductor wafers, the method comprising the following steps: providing a layer of undoped SiO 2 atop a wafer; providing a layer of doped SiO 2 atop the layer of undoped SiO 2 ; and wet etching the layer of doped SiO 2 selectively relative to the undoped layer of SiO 2 and selectively relative to silicon utilizing an acid solution, the acid solution comprising a mixture of at least two different mineral acids provided in a selected ratio relative to one another, one of the mineral acids being HF, the other of the mineral acids being H 2 SO 4 .
Claim 11
Dependent Claim
35 words
The method of utilizing and etching SiO 2 of claim 8 wherein the volumetric ratio of H 2 SO 4 in the acid solution to HF in the acid solution is from 20:1 to 110:1.
Claim 12
Dependent Claim
35 words
The method of utilizing and etching SiO 2 of claim 8 wherein the volumetric ratio of H 2 SO 4 in the acid solution to HF in the acid solution is from 45:1 to 65:1.
Claim 13
Dependent Claim
33 words
The method of utilizing and etching SiO 2 of claim 8 wherein the volumetric ratio of H 2 SO 4 in the acid solution to HF in the acid solution is about 55:1.
Claim 14
Dependent Claim
21 words
The method of utilizing and etching SiO 2 of claim 8 wherein the doped layer of SiO 2 comprises borophosphosilicate glass.
Claim 15
Dependent Claim
45 words
The method of utilizing and etching SiO 2 of claim 8 wherein, the volumetric ratio of H 2 SO 4 in the acid solution to HF in the acid solution is from 20:1 to 110:1; and the doped layer of SiO 2 comprises borophosphosilicate glass.
Claim 16
Dependent Claim
45 words
The method of utilizing and etching SiO 2 of claim 8 wherein, the volumetric ratio of H 2 SO 4 in the acid solution of HF in the acid solution is from 45:1 to 65:1; and the doped layer of SiO 2 comprises borophosphosilicate glass.
Claim 17
Dependent Claim
25 words
The method of utilizing and etching SiO 2 of claim 1 wherein the acid solution consists essentially of HF and H 2 SO 4 .
Claim 18
Dependent Claim
25 words
The method of utilizing and etching SiO 2 of claim 1 wherein the acid solution consists essentially of HF and H 3 PO 4 .
Claim 19
Dependent Claim
21 words
The method of utilizing and etching SiO 2 of claim 1 wherein the acid solution consists essentially of HF and HBr.
Claim 20
Dependent Claim
21 words
The method of utilizing and etching SiO 2 of claim 1 wherein the acid solution consists essentially of HF and HI.
Claim 21
Dependent Claim
23 words
The method of utilizing and etching SiO 2 of claim 1 wherein the acid solution consists essentially of HF and HClO 4 .
Claim 22
Dependent Claim
23 words
The method of utilizing and etching SiO 2 of claim 1 wherein the acid solution consists essentially of HF and HIO 4 .
References Cited (Backward Citations)
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