Patent EP0729175A1 successfully refreshed from Google Patents.
EP0729175A1
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Method for producing deep vertical structures in silicon substrates
Assignee: International Business Machines Corp
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Filing: 1995-02-24
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Granted: —
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Expires: 2015-02-24
Abstract
Abstract A method is provided for producing deep substantially vertical structures in silicon substrates, wherein in a first step, the silicon substrate is anisotropically plasma etched to a first predetermined depth, thereby creating a first structure. Subsequently, the surface of the substrate is covered conformally with an etch-resistant coating, and the horizontal parts of said coating are selectively removed. Following this removal, the substrate is anisotropically plasma etched at low temperatures to a second predetermined depth with a mixture of SF 6 /O 2 , whereby a second structure is created. Finally, the vertical parts of the coating are removed.
Inventors
- 👤 Johann Dr. Bartha
- 👤 Johann Dr. Greschner
- 👤 Robert Dr. Junginger
- 👤 Georg Kraus
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 18:12
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/24; H10P50/242; H10P50/244; H10P50/69; H10P50/691; H10P50/692
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
88 words
Method for producing deep substantially vertical structures in silicon substrates, comprising the steps of a) anisotropically plasma etching the silicon substrate to a first predetermined depth, b) covering the surface of said substrate showing said first structure conformally with an etch-resistant coating, c) selectively removing the horizontal parts of said coating, d) anisotropically plasma etching the substrate at low temperatures to a second predetermined depth with a mixture of SF 6 /O 2 , thereby creating a second structure, and e) removing the vertical parts of said coating.
Claim 2
Dependent Claim
39 words
Method according to claim 1 wherein said mixture of SF 6 /O 2 contains about 5% to about 30% O 2 and about 95 to about 70% SF 6 , preferably 20% O 2 and 80% SF 6 .
Claim 3
Dependent Claim
28 words
Method according to claim 1 or 2, wherein the temperature of the etching in step d) is in the range between -80°C and -120°C, and especially is -100°C.
Claim 4
Dependent Claim
41 words
Method according to claim 1 or 2 wherein said etching in step a) is performed for about 10 minutes using a microwave power of about 1500 W, a substrate bias of about -25 V at a pressure of about 1 Pa.
Claim 5
Dependent Claim
32 words
Method according to any one of claims 1 to 4, wherein the etching in step a) is performed by RIE or by using a gas mixture of SF 6 /O 2 .
Claim 6
Dependent Claim
19 words
Method according to any one of claims 1 to 5, wherein said etch-resistant coating consists of an ice film.
Claim 7
Dependent Claim
18 words
Method according to any one of claims 1 to 5, wherein said coating is a thermal oxide coating.
Claim 8
Dependent Claim
22 words
Method according to claim 6, wherein the ice film is applied by condensing water vapor on the surface of the first structure.
Claim 9
Dependent Claim
16 words
Method according to claim 8, wherein the water partial pressure is between 0.1 and 0.5 Pa.
Claim 10
Dependent Claim
26 words
Method according to any one of claims 6, 8 or 9, wherein the horizontal parts of the ice film are removed by sputter etching with argon.
Claim 11
Dependent Claim
29 words
Method according to any one of the preceding claims, wherein the growing of said coating and/or the removal of said ice film is controlled by means of an interferometer.
Claim 12
Dependent Claim
52 words
Method according to any one of claims 1 to 7, wherein the thickness of said coating on the horizontal parts of the substrate is between 1 and 1.5 micrometer and wherein the thickness of said coating on the vertical parts is about half the thickness of said coating on the horizontal parts.
Claim 13
Dependent Claim
40 words
Method according to claim 10, wherein said sputter etching is performed with an argon flow of about 20 sccm, a reactor pressure of about 0.4 Pa, a microwave power of about 1500 W and a DC-bias of about -200 V.
Claim 14
Dependent Claim
28 words
Method according to any one of the preceding claims, wherein the first predetermined depth is about 10 to about 50 µm, preferably about 20 to about 40 µm.
Claim 15
Dependent Claim
24 words
Method according to any one of the preceding claims, wherein the second predetermined depth is about 30 to 90 µm, preferably about 50 µm.
Claim 16
Dependent Claim
17 words
Method according to any one of the preceding claims, wherein steps a) to e) are performed repeatedly.
Claim 17
Dependent Claim
21 words
Use of the method according to any one of the preceding claims for the fabrication of guide plates for test probes.
References Cited (Backward Citations)
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