US4574177A
Expired / Lapsed
US
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Plasma etch method for TiO2
Assignee: Texas Instruments Inc
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Filing: 1984-11-13
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Granted: 1986-03-04
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Expires: 2004-11-13
Abstract
Abstract A method for plasma etching of TiO 2 , using a mixture of oxygen and a fluorine-bearing species, preferably CF 4 . This mixture gives good selectivity over aluminum and photoresist, and approximately unity selectivity over silica or silicon nitride. Use of a chlorine-containing species is also taught by the invention, and will provide different selectivities. The present invention is also useful for etching in the RIE mode.
Inventors
- 👤 Chung S. Wang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:49
CPC Classifications
H; H10; H10F; H10F71/00; H10F71/138; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; Y; Y02; Y02E; Y02E10/00; Y02E10/50
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
72 words
A method for selectively etching a layer of TiO 2 , comprising the steps of: (a) providing a layer of TiO 2 ; (b) forming a patterned layer of masking material on said TiO 2 ; (c) exposing said patterned TiO 2 layer to an atmosphere of a carbohalogen and oxygen at a pressure greater than 0.1 Torr; and (d) applying RF power to said carbohalogen atmosphere near said TiO 2 layer.
Claim 2
Independent Claim
72 words
A method for selectively etching a layer of TiO 2 , comprising the steps of: (a) providing a layer of TiO 2 ; (b) forming a patterned layer of masking material on said TiO 2 ; (c) exposing said patterned TiO 2 layer to an atmosphere of a carbohalogen and oxygen at a pressure greater than 0.1 Torr; and (d) applying RF power to said carbohalogen atmosphere near said TiO 2 layer.
Claim 3
Dependent Claim
22 words
The method of claim 1, wherein said halogen-bearing species contains a halogen element selected from the group consisting of chlorine and fluorine.
Claim 4
Dependent Claim
13 words
The method of claim 2, wherein said halogen-bearing species is a fluorine-bearing species.
Claim 5
Dependent Claim
16 words
The method of claim 3, wherein said gas mixture comprises CF 4 and O 2 .
Claim 6
Dependent Claim
51 words
The method of claim 4, wherein said gas mixture is flowed at a rate of between 50 and 400 standard cubic centimeters per minute of CF 4 and between 1 and 8 standard cubic centimeters per minute of O 2 , at an absolute pressure of between 100 and 1,000 microns.
Claim 7
Dependent Claim
13 words
The method of claim 2, wherein said gas mixture comprises a chlorine-bearing species.
Claim 8
Dependent Claim
13 words
The method of claim 6, wherein said gas mixture comprises CCl 4 .
Claim 9
Dependent Claim
14 words
The method of claim 1, 2, or 5, wherein said masking material comprises photoresist.
Claim 10
Dependent Claim
41 words
The method of claim 1, wherein said step of providing a layer of TiO 2 , said layer substantially rutile, comprises the steps of: depositing a layer of metallic titanium; oxidizing said titanium to provide said layer of TiO 2 .
Claim 11
Independent Claim
96 words
A method for forming polysilicon gates for MIS transistors, comprising the steps of: (a) providing a semiconductor surface; (b) forming a thin insulating layer on said surface; (c) forming a layer of TiO 2 on said thin insulating layer; (d) forming a layer of polysilicon on said TiO 2 layer; (e) forming a patterned layer of photoresist on said polysilicon layer; (f) plasma etching said polysilicon layer; (g) plasma etching said patterned TiO 2 layer in a mixture of a carbohalogen species and oxygen; and (h) etching said thin insulator layer; whereby polysilicongate structures are defined.
Claim 12
Independent Claim
96 words
A method for forming polysilicon gates for MIS transistors, comprising the steps of: (a) providing a semiconductor surface; (b) forming a thin insulating layer on said surface; (c) forming a layer of TiO 2 on said thin insulating layer; (d) forming a layer of polysilicon on said TiO 2 layer; (e) forming a patterned layer of photoresist on said polysilicon layer; (f) plasma etching said polysilicon layer; (g) plasma etching said patterned TiO 2 layer in a mixture of a carbohalogen species and oxygen; and (h) etching said thin insulator layer; whereby polysilicongate structures are defined.
Claim 13
Independent Claim
66 words
A method for selectively etching a layer of rutile, comprising the steps of: (a) providing a layer of rutile; (b) forming a patterned layer of masking material on said rutile; (c) exposing said patterned rutile layer to an atmosphere of a carbohalogen and oxygen at a pressure greater than 0.1 Torr; and (d) applying RF power to said carbohalogen and oxygen atmosphere near said rutile layer.
Claim 14
Independent Claim
66 words
A method for selectively etching a layer of rutile, comprising the steps of: (a) providing a layer of rutile; (b) forming a patterned layer of masking material on said rutile; (c) exposing said patterned rutile layer to an atmosphere of a carbohalogen and oxygen at a pressure greater than 0.1 Torr; and (d) applying RF power to said carbohalogen and oxygen atmosphere near said rutile layer.
Claim 15
Independent Claim
66 words
A method of etching TiO 2 selectively relative to aluminum and photoresist, and at a rate at least comparable to that of silicon, silicon dioxide, and silicon nitride, comprising the steps of: (a) providing exposed surfaces of TiO 2 and aluminum; (b) flowing a gas mixture over said TiO 2 and aluminum simultaneously, including a fluorocarbon plus oxygen; and (c) exciting said mixture into a plasma.
Claim 16
Independent Claim
66 words
A method of etching TiO 2 selectively relative to aluminum and photoresist, and at a rate at least comparable to that of silicon, silicon dioxide, and silicon nitride, comprising the steps of: (a) providing exposed surfaces of TiO 2 and aluminum; (b) flowing a gas mixture over said TiO 2 and aluminum simultaneously, including a fluorocarbon plus oxygen; and (c) exciting said mixture into a plasma.
Claim 17
Dependent Claim
23 words
The method of claim 12, wherein: (a) said gas mixture has a total pressure in the range of 100 microns to 1000 microns.
Claim 18
Dependent Claim
26 words
the method of claim 12, wherein: (a) said gas mixture essentially consists of fluorocarbon plus oxygen with the ratio of fluorocarbon to oxygen greater than one.
References Cited (Backward Citations)
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