US5877090A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective plasma etching of silicon nitride in presence of silicon or silicon oxides using mixture of NH3 or SF6 and HBR and N2
Assignee: Applied Materials Inc
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Filing: 1997-06-03
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Granted: 1999-03-02
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Expires: 2017-06-03
Abstract
Abstract An RIE method and apparatus provides uniform and selective etching through silicon nitride material of a supplied workpiece such as a silicon wafer having silicon oxide adjacent to the SiN. A plasma-maintaining gas that includes N 2 having an inflow rate of at least 10 sccm is used to provide etch-depth uniformity across the workpiece. The plasma-maintaining gas further includes HBr and one or both of NF 3 and SF 6 .
Inventors
- 👤 Nallan C. Padmapani
- 👤 Terry Ko
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 19:00
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
138 words
A selective etching method for providing substantially uniform etching of silicon nitride material provided across a surface of a supplied workpiece, the workpiece surface having a span of at least 6 inches, said method being such that deviation of etch depth across the span of the workpiece surface is substantially equal to or less than 10 percent, said method comprising the steps of: (a) flowing an input gas including: (a.1) at least one of NF 3 and SF 6 , (a.2) HBr, and (a.3) N 2 into a low-pressure chamber containing said workpiece; (b) maintaining a pressure of 300 milliTorr or less in said chamber; and (c) applying electromagnetic energy to the supplied input gas so as to form a plasma; (a.3.i) wherein the inflow rate of the N 2 is equal to or greater than 10 sccm.
Claim 2
Dependent Claim
138 words
A selective etching method for providing substantially uniform etching of silicon nitride material provided across a surface of a supplied workpiece, the workpiece surface having a span of at least 6 inches, said method being such that deviation of etch depth across the span of the workpiece surface is substantially equal to or less than 10 percent, said method comprising the steps of: (a) flowing an input gas including: (a.1) at least one of NF 3 and SF 6 , (a.2) HBr, and (a.3) N 2 into a low-pressure chamber containing said workpiece; (b) maintaining a pressure of 300 milliTorr or less in said chamber; and (c) applying electromagnetic energy to the supplied input gas so as to form a plasma; (a.3.i) wherein the inflow rate of the N 2 is equal to or greater than 10 sccm.
Claim 3
Dependent Claim
24 words
An etching method according to claim 1 wherein: (a.3.ii) the inflow rate of the N 2 is equal to or greater than 20 sccm.
Claim 4
Dependent Claim
24 words
An etching method according to claim 2 wherein: (a.3.iii) the inflow rate of the N 2 is equal to or greater than 40 sccm.
Claim 5
Dependent Claim
34 words
An etching method according to claim 1 wherein: (a.1.i) said input gas includes SF 6 , and (a.2.i) the inflow rate of the HBr is in the range of about 5 to 15 sccm.
Claim 6
Dependent Claim
32 words
An etching method according to claim 4 wherein: (a.1.ii) the inflow rate of the SF 6 is about 80 sccm, and (a.2.ii) the inflow rate of the HBr is about 15 sccm.
Claim 7
Dependent Claim
34 words
An etching method according to claim 1 wherein: (a.1.i) said input gas includes NF 3 , and (a.2.i) the inflow rate of the HBr is in the range of about 20 to 40 sccm.
Claim 8
Dependent Claim
32 words
An etching method according to claim 6 wherein: (a.1.ii) the inflow rate of the NF 3 is about 90 sccm, and (a.2.ii) the inflow rate of the HBr is about 30 sccm.
Claim 9
Dependent Claim
20 words
An etching method according to claim 1 wherein: said supplied workpiece includes silicon oxide adjacent to the silicon nitride material.
Claim 10
Dependent Claim
19 words
An etching method according to claim 8 wherein said silicon oxide has a thickness of 100 Å or less.
Claim 11
Dependent Claim
28 words
An etching method according to claim 1 wherein in a first phase of etching said input gas consists essentially of SF 6 and HBr and N 2 .
Claim 12
Dependent Claim
28 words
An etching method according to claim 10 wherein in a second phase of etching said input gas consists essentially of NF 3 and HBr and N 2 .
Claim 13
Dependent Claim
30 words
An etching method according to claim 11 wherein the second phase of etching occurs after the first phase of etching and wherein final etch-through is achieved in the second phase.
Claim 14
Dependent Claim
50 words
An etch method according to claim 1 further comprising the step of: (d) providing a mask layer over the silicon nitride material, the mask layer having one or more apertures defined through the mask layer for exposing a corresponding one or more prespecified surface portions of the silicon nitride material.
Claim 15
Independent Claim
109 words
A system for etching-through a material layer consisting essentially of silicon nitride, said system comprising: (a) a chamber for supporting the material layer there within; (b) supply means for supplying a input-gas containing at least one of NF 3 and SF 6 , and further containing HBr and N 2 into the chamber, said N 2 having an inflow rate of at least 10 sccm; (c) vacuum means for maintaining a pressure at least as low as approximately 300 milliTorr within the chamber; and (d) electromagnetic energy generator means for supplying electromagnetic energy into the chamber and thereby reacting said input-gas with the material layer supported within the chamber.
Claim 16
Independent Claim
109 words
A system for etching-through a material layer consisting essentially of silicon nitride, said system comprising: (a) a chamber for supporting the material layer there within; (b) supply means for supplying a input-gas containing at least one of NF 3 and SF 6 , and further containing HBr and N 2 into the chamber, said N 2 having an inflow rate of at least 10 sccm; (c) vacuum means for maintaining a pressure at least as low as approximately 300 milliTorr within the chamber; and (d) electromagnetic energy generator means for supplying electromagnetic energy into the chamber and thereby reacting said input-gas with the material layer supported within the chamber.
References Cited (Backward Citations)
JPS5621330A
Cited
US4717447A
Cited
DE3714144A1
Cited
US4793897A
Cited
US4857140A
Cited
US4820378A
Cited
US5431772A
Cited
US5318668A
Cited
US5338395A
Cited
US5413670A
Cited
US5387312A
Cited
EP0658928A1
Cited
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| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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