Patent EP0651434A2 successfully refreshed from Google Patents.
EP0651434A2
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Oxide etch process with high selectivity to nitride suitable for use on surfaces of uneven topography
Assignee: Applied Materials Inc
•
Filing: 1994-10-28
•
Granted: —
•
Expires: 2014-10-28
Abstract
Abstract A plasma etch process is described for the etching of oxide (30) with a high selectivity to nitride, including nitride (20) formed on uneven surfaces of a substrate (2), e.g., on sidewalls of steps (10, 12) on an integrated circuit structure. The addition of one or more hydrogen-containing gases, preferably one or more hydrofluorocarbon gases, to one or more fluorine-substituted hydrocarbon etch gases and a scavenger for fluorine, in a plasma etch process for etching oxide in preference to nitride, results in a high selectivity to nitride which is preserved regardless of the topography of the nitride portions (22, 26) of the substrate surface. In a preferred embodiment, one or more oxygen-bearing gases are also added to reduce the overall rate of polymer deposition on the chamber surfaces and on the surfaces to be etched, which can otherwise reduce the etch rate and cause excessive polymer deposition on the chamber surfaces. The fluorine scavenger is preferably an electrically grounded silicon electrode associated with the plasma.
Inventors
- 👤 Chan Lon Yang
- 👤 Jeffrey Marks
- 👤 Nicolas Bright
- 👤 Kenneth S. Collins
- 👤 David Groechel
- 👤 Peter Keswick
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 13:28
CPC Classifications
H; H01; H01J; H01J37/00; H01J37/32; H01J37/32431; H01J37/32798; H01J37/32853; H01J37/32871; H01J37/32009; H01J37/32082; H01J37/321; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283; H01J2237/00; H01J2237/32; H01J2237/33; H01J2237/334; H01J2237/3343; H01J2237/3346; H01J2237/3347
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
56 words
A process for plasma etching oxide in the presence of nitride capable of exhibiting high selectivity to nitride, including nitride on uneven surfaces, which comprises contacting said oxide with a mixture of gases comprising: a) one or more fluorine-substituted hydrocarbon etching gases; and b) one or more hydrogen-bearing gases; in the presence of a fluorine scavenger.
Claim 2
Dependent Claim
34 words
The process of claim 1, wherein the total amount of said one or more hydrogen-bearing gases ranges from about 1 vol.% to about 100 vol.% of said one or more fluorine-substituted hydrocarbon etching gases.
Claim 3
Dependent Claim
28 words
The process of claim 1 or 2, wherein said one or more fluorine-substituted hydrocarbon gases each have a formula C x F (2x+2) , where x is 1-3.
Claim 4
Dependent Claim
59 words
The process of claim 1 or 2, wherein said one or more hydrogen-bearing gases is selected from the group consisting of hydrogen, one or more hydrofluorocarbons having the formula C x H Y F z , and mixtures of two or more of same, where x is 1-3, y is from 1 to 2x+1, and z is 2x+2-y .
Claim 5
Dependent Claim
35 words
The process of claim 1 or 2, wherein said one or more hydrogen-bearing gases is selected from the group consisting of monofluoromethane (CH₃F), difluoromethane (CH₂F₂), trifluoromethane (CHF₃), and mixtures of two or more of same.
Claim 6
Dependent Claim
19 words
The process of claim 1 or 2, wherein said one or more hydrogen-bearing gases consists essentially of monofluoromethane (CH₃F).
Claim 7
Dependent Claim
38 words
The process of claim 2, wherein said mixture of gases further comprises one or more oxygen-bearing gases in an amount ranging from about 1 vol.% to about 300 vol.% of said one or more fluorine-substituted hydrocarbon etching gases.
Claim 8
Dependent Claim
56 words
The process of claim 7, wherein said one or more oxygen-bearing gases are selected from the group consisting of oxygen (O₂), ozone (O₃), carbon monoxide (CO), carbon dioxide (CO₂) an oxide of nitrogen (N x O y , where x is 1-2 and y is 1 to 2), and mixtures of two or more of same.
Claim 9
Dependent Claim
27 words
The process of claim 7, wherein said one or more oxygen-bearing gases are selected from the group consisting of carbon monoxide, carbon dioxide, and mixtures of same.
Claim 10
Dependent Claim
19 words
The process of claim 2, wherein said fluorine scavenger is selected from the group consisting of silicon and carbon.
Claim 11
Dependent Claim
19 words
The process of claim 10, wherein said fluorine scavenger is a silicon surface spaced from said oxide and nitride.
Claim 12
Dependent Claim
17 words
The process of claim 11, wherein said silicon surface fluorine scavenger is electrically associated with said plasma.
Claim 13
Dependent Claim
13 words
The process of claim 11, wherein said silicon surface fluorine scavenger is grounded.
Claim 14
Dependent Claim
26 words
The process of claim 11, wherein said silicon surface fluorine scavenger is maintained at a temperature within a range of from about 200°C to about 280°C.
Claim 15
Dependent Claim
141 words
An oxide plasma etch process capable of exhibiting high selectivity to nitride, including nitride sidewalls in an integrated circuit structure on a substrate, which comprises; a) loading into an etch chamber a substrate containing an oxide layer and a nitride layer; b) flowing into said etch chamber: i) one or more fluorine-substituted hydrocarbon etching gases having the formula C x F (2x+2) , where x is 1-3; ii) one or more hydrogen-bearing gases consisting essentially of hydrofluorocarbons having the formula C x H Y F z , where x is 1-3, y is from 1 to 2x+1, and z is 2x+2- y ; and iii) optionally one or more oxygen-bearing gases; c) igniting a plasma in said chamber; and d) contacting a fluorine scavenger with said plasma; whereby said oxide layer will be etched while maintaining a high selectivity to nitride.
Claim 16
Dependent Claim
38 words
The process of claim 15, wherein the total amount of said one or more hydrogen-bearing gases flowing into said chamber ranges from about 1 vol.% to about 100 vol.% of said one or more fluorine-substituted hydrocarbon etching gases.
Claim 17
Dependent Claim
38 words
The process of claim 15, wherein the total amount of said one or more hydrogen-bearing gases flowing into said chamber ranges from about 5 vol.% to about 30 vol.% of said one or more fluorine-substituted hydrocarbon etching gases.
Claim 18
Dependent Claim
38 words
The process of claim 15, wherein the total amount of said one or more oxygen-bearing gases flowing into said chamber ranges from about 0 vol.% to about 300 vol.% of said one or more fluorine-substituted hydrocarbon etching gases.
Claim 19
Dependent Claim
16 words
The process of claim 15, wherein said fluorine scavenger in contact with said plasma comprises silicon.
Claim 20
Dependent Claim
17 words
The process of claim 15, wherein said fluorine scavenger comprises solid silicon in contact with said plasma.
Claim 21
Dependent Claim
14 words
The process of claim 20, wherein said solid silicon fluorine scavenger is electrically grounded.
Claim 22
Dependent Claim
18 words
The process of claim 19, wherein said fluorine scavenger comprises a silicon-containing gas in contact with said plasma.
Claim 23
Dependent Claim
69 words
A process for plasma etching oxide in the presence of nitride capable of exhibiting high selectivity to nitride, including nitride on uneven surfaces, which comprises contacting said oxide with a mixture of gases comprising: a) one or more fluorine-substituted hydrocarbon etching gases; b) one or more hydrogen-bearing gases; and c) optionally, one or more oxygen-bearing gases; in the presence of a fluorine scavenger comprising an electrically grounded silicon electrode.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
Maintenance schedule is calculated for granted US utility patents.