US5786276A
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Selective plasma etching of silicon nitride in presence of silicon or silicon oxides using mixture of CH3F or CH2F2 and CF4 and O2
Assignee: Applied Materials Inc
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Filing: 1997-03-31
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Granted: 1998-07-28
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Expires: 2017-03-31
Abstract
Abstract A chemical downstream etching (CDE) that is selective to silicon nitrides (SiN) over silicon oxides (SiO) uses at least one of a CH3F/CF4/O2 recipe and a CH2F2/CF4/O2 recipe. Inflow rates are mapped for the respective components of the input recipe to find settings that provide both high nitride etch rates and high selectivity towards the SiN material. A pins-up scheme is used for simultaneously stripping away backside nitride with topside nitride.
Inventors
- 👤 Cynthia B. Brooks
- 👤 Walter Merry
- 👤 Ajey M. Joshi
- 👤 Gladys D. Quinones
- 👤 Jitske Trevor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:14
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/28; H10P50/282; H10P50/283
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
86 words
An etch method for etching a supplied first material layer consisting essentially of a silicon nitride, said method comprising the steps of: (a) supplying an input gas including at least one of CH 3 F and CH 2 F 2 and further including CF 4 and O 2 to a vicinity spaced away from the material layer; (b) applying electromagnetic energy to the supplied input gas so as to form a plasma; and (c) applying an outflow of the formed plasma to said first material layer.
Claim 2
Dependent Claim
86 words
An etch method for etching a supplied first material layer consisting essentially of a silicon nitride, said method comprising the steps of: (a) supplying an input gas including at least one of CH 3 F and CH 2 F 2 and further including CF 4 and O 2 to a vicinity spaced away from the material layer; (b) applying electromagnetic energy to the supplied input gas so as to form a plasma; and (c) applying an outflow of the formed plasma to said first material layer.
Claim 3
Dependent Claim
24 words
An etch method according to claim 1 wherein said input gas consists essentially of CH 3 F and CF 4 and O 2 .
Claim 4
Dependent Claim
28 words
An etch method according to claim 2 wherein the total flow rate of said input gas is in the range of about 350 sccm to about 600 sccm.
Claim 5
Dependent Claim
35 words
An etch method according to claim 3 wherein the CH 3 F component of the input gas has a mole fraction contribution to the input gas in the range of about 0.12 to about 0.22.
Claim 6
Dependent Claim
34 words
An etch method according to claim 4 wherein the O 2 component of the input gas has a mole fraction contribution to the input gas in the range of about 0.32 to about 0.55.
Claim 7
Dependent Claim
34 words
An etch method according to claim 5 wherein the CF 4 component of the input gas has a mole fraction contribution to the input gas in the range of about 0.30 to about 0.48.
Claim 8
Dependent Claim
29 words
An etch method according to claim 1 wherein said input gas includes an inflow of CH 3 F in the range of about 42 sccm to about 132 sccm.
Claim 9
Dependent Claim
28 words
An etch method according to claim 7 wherein said input gas includes an inflow of O 2 in the range of about 112 sccm to about 330 sccm.
Claim 10
Dependent Claim
28 words
An etch method according to claim 8 wherein said input gas includes an inflow of CF 4 in the range of about 105 sccm to about 288 sccm.
Claim 11
Dependent Claim
25 words
An etch method according to claim 1 wherein said input gas consists essentially of CH 2 F 2 and CF 4 and O 2 .
Claim 12
Dependent Claim
28 words
An etch method according to claim 10 wherein the total flow rate of said input gas is in the range of about 350 sccm to about 600 sccm.
Claim 13
Dependent Claim
36 words
An etch method according to claim 11 wherein the CH 2 F 2 component of the input gas has a mole fraction contribution to the input gas in the range of about 0.12 to about 0.48.
Claim 14
Dependent Claim
34 words
An etch method according to claim 12 wherein the O 2 component of the input gas has a mole fraction contribution to the input gas in the range of about 0.3 to about 0.65.
Claim 15
Dependent Claim
34 words
An etch method according to claim 13 wherein the CF 4 component of the input gas has a mole fraction contribution to the input gas in the range of about 0.1 to about 0.4.
Claim 16
Dependent Claim
30 words
An etch method according to claim 1 wherein said input gas includes an inflow of CH 2 F 2 in the range of about 42 sccm to about 288 sccm.
Claim 17
Dependent Claim
28 words
An etch method according to claim 15 wherein said input gas includes an inflow of O 2 in the range of about 105 sccm to about 390 sccm.
Claim 18
Dependent Claim
28 words
An etch method according to claim 16 wherein said input gas includes an inflow of CF 4 in the range of about 35 sccm to about 240 sccm.
Claim 19
Dependent Claim
17 words
An etch method according to claim 1 wherein said plasma is spaced apart from the material layer.
References Cited (Backward Citations)
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| 7.5 Years (Year 8) | 2005-07-27 | 2006-01-26 | 2006-07-28 | $3760.00 | Window Closed / Lapsed |
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