US5354416A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dry etching method
Assignee: Individual
•
Filing: 1990-04-02
•
Granted: 1994-10-11
•
Expires: 2010-04-02
Abstract
Abstract Etching of an article is carried out by maintaining the article at a temperature at which the vapor pressure of etching gas molecules becomes equal to or higher than the pressure of etching gas and the vapor pressure of neutral radicals contained in a plasma becomes equal to or lower than the pressure of an etching gas. An etching pattern with a substantially vertical side profile and extremely small in dimensional shift from the mask can be formed at high precision.
Inventors
- 👤 Sadayuki Okudaira
- 👤 Kazunori Tsujimoto
- 👤 Shinichi Tachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:18
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/20; H10P50/26; H10P50/264; H10P50/266; H10P50/24; H10P50/242; H10P50/267; H10P50/268
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
218 words
A dry etching method for etching an article, the article having a patterned photoresist mask thereon, portions of the article thus being exposed through openings in said patterned photoresist mask, comprising: placing said article in a vessel containing an etching gas and having a predetermined overall gas pressure of 1-100 mTorr; and etching said article, in the presence of said patterned photoresist mask, to vertically etch said portions of said article to form patterns having sidewall portions, by contacting plasma of said etching gas with said portions of said article which are exposed through said openings in said photoresist mask, while maintaining the temperature of said article above a temperature at which the vapor pressure of said etching gas molecules becomes equal to said overall gas pressure, below a temperature at which the vapor pressure of reaction product produced from the reaction of (a) neutral radicals contained in said plasma and (b) material of said sidewall portions formed during said etching of said article becomes 10 4 ×the pressure of said overall gas pressure, wherein said particle is maintained while being contacted with said plasma of said etching gas at a temperature of -50° c. or below, so as to substantially avoid etching of said sidewall portions due to neutral radicals in the plasma of the etching gas.
Claim 2
Dependent Claim
218 words
A dry etching method for etching an article, the article having a patterned photoresist mask thereon, portions of the article thus being exposed through openings in said patterned photoresist mask, comprising: placing said article in a vessel containing an etching gas and having a predetermined overall gas pressure of 1-100 mTorr; and etching said article, in the presence of said patterned photoresist mask, to vertically etch said portions of said article to form patterns having sidewall portions, by contacting plasma of said etching gas with said portions of said article which are exposed through said openings in said photoresist mask, while maintaining the temperature of said article above a temperature at which the vapor pressure of said etching gas molecules becomes equal to said overall gas pressure, below a temperature at which the vapor pressure of reaction product produced from the reaction of (a) neutral radicals contained in said plasma and (b) material of said sidewall portions formed during said etching of said article becomes 10 4 ×the pressure of said overall gas pressure, wherein said particle is maintained while being contacted with said plasma of said etching gas at a temperature of -50° c. or below, so as to substantially avoid etching of said sidewall portions due to neutral radicals in the plasma of the etching gas.
Claim 3
Dependent Claim
31 words
The method according to claim 1, wherein said article is maintained at a temperature at which the vapor pressure of said reaction product becomes 10 3 times the overall gas pressure.
Claim 4
Dependent Claim
31 words
The method according to claim 1, wherein said article is maintained at a temperature at which the vapor pressure of said reaction product becomes 10 2 times the overall gas pressure.
Claim 5
Dependent Claim
33 words
The method according to claim 1, wherein said article is maintained at a temperature at which the vapor pressure of said reaction product becomes equal to or less than the overall gas pressure.
Claim 6
Dependent Claim
13 words
The method according to claim 1, wherein said etching is reactive ion etching.
Claim 7
Dependent Claim
13 words
The method according to claim 1, wherein said etching is microwave plasma etching.
Claim 8
Dependent Claim
33 words
The method according to claim 1, wherein said etching gas is at least one member selected from the group consisting of F 2 , Cl 2 , SF 6 and NF 3 .
Claim 9
Dependent Claim
37 words
The method according to claim 1, wherein said article and said etching gas are tungsten and CF 4 , respectively, and said article is maintained at a temperature in the range from -5° C. to -160° C.
Claim 10
Dependent Claim
23 words
The method according to claim 8, wherein said article is maintained at a temperature in the range from -50° C. to -160° C.
Claim 11
Dependent Claim
37 words
The method according to claim 1, wherein said article and said etching gas are silicon and SF 6 , respectively, and said article is maintained at a temperature in the range from -95° C. to '1145° C.
Claim 12
Dependent Claim
23 words
The method according to claim 10, wherein said article is maintained at a temperature in the range from -130° C. to -145° C.
Claim 13
Dependent Claim
37 words
The method according to claim 1, wherein said article and said etching gas are silicon and CF 4 , respectively, and said article is maintained at a temperature in the range from -95° C. to -190° C.
Claim 14
Dependent Claim
23 words
The method according to claim 12, wherein said article is maintained at a temperature in the range from -130° C. to '1190° C.
Claim 15
Dependent Claim
36 words
The method according to claim 1, wherein the article and said etching gas are tungsten and SF 6 , respectively, and the article is maintained at a temperature in the range from -60° to -150° C.
Claim 16
Dependent Claim
18 words
The method according to claim 1, wherein the etching gas does not contain any carbon, boron or silicon.
Claim 17
Dependent Claim
57 words
The method according to claim 1, wherein the temperature of the article is at least 5° C. above said temperature at which the overall gas vapor pressure molecules becomes equal to the pressure of said etching gas and below said temperature at which the vapor pressure of said reaction product becomes 10 4 times the overall gas.
Claim 18
Dependent Claim
61 words
The method according to claim 1, wherein said etching is carried out said overall gas pressure and at the article temperature so as to substantially avoid etching of sidewall portions of said openings in the photoresist mask formed during etching, as well as etching of said sidewall portions of the article, by neutral radicals in the plasma of the etching gas.
Claim 19
Dependent Claim
63 words
The method according to claim 1, wherein said article is made of a material selected from the group consisting of silicon and tungsten, said etching gas is at least one member selected from the group consisting of F 2 , Cl 2 , SF 6 and NF 3 , and wherein said etching is one of reactive ion etching and microwave plasma etching.
Claim 20
Dependent Claim
151 words
A dry etching method for etching an article, the article having a patterned photoresist mask thereon, portions of the article thus being exposed through openings in said patterned photoresist mask, comprising: placing said article in a vessel containing an etching gas and having a predetermined overall gas pressure of 1-100 mTorr; and etching said article, in the presence of said patterned photoresist mask, to vertically etch said portions of said article to form patterns having sidewall portions, by contacting plasma of said etching gas with said portions said article which are exposed through said openings in said photoresist mask, while maintaining the temperature of a article above said temperature at which the vapor pressure of said etching gas molecules becomes equal to said overall gas pressure and below -95° C., so as to substantially avoid etching of said sidewall portions due to neutral radicals in the plasma of the etching gas.
Claim 21
Dependent Claim
151 words
A dry etching method for etching an article, the article having a patterned photoresist mask thereon, portions of the article thus being exposed through openings in said patterned photoresist mask, comprising: placing said article in a vessel containing an etching gas and having a predetermined overall gas pressure of 1-100 mTorr; and etching said article, in the presence of said patterned photoresist mask, to vertically etch said portions of said article to form patterns having sidewall portions, by contacting plasma of said etching gas with said portions said article which are exposed through said openings in said photoresist mask, while maintaining the temperature of a article above said temperature at which the vapor pressure of said etching gas molecules becomes equal to said overall gas pressure and below -95° C., so as to substantially avoid etching of said sidewall portions due to neutral radicals in the plasma of the etching gas.
Claim 22
Dependent Claim
13 words
The method according to claim 19, wherein said etching is reactive ion etching.
Claim 23
Dependent Claim
13 words
The method according to claim 19, wherein said etching is microwave plasma etching.
Claim 24
Dependent Claim
33 words
The method according to claim 19, wherein said etching gas is at least one member selected from the group consisting of F 2 , Cl 2 , SF 6 and NF 3 .
Claim 25
Dependent Claim
18 words
The method according to claim 19, wherein the etching gas does not contain any carbon, boron or silicon.
Claim 26
Dependent Claim
41 words
The method according to claim 19, wherein the temperature of the article is at least 5° C. above said temperature at which the vapor pressure of said etching gas molecules becomes equal to the overall gas pressure and below -95° C.
Claim 27
Dependent Claim
59 words
The method according to claim 19, wherein said etching is carried out at said overall gas pressure and at the article temperature so as to substantially avoid etching of sidewall portions of said opining in the photoresist mask, as well as etching of said sidewall portions of the article, by neutral radicals in the plasma of the etching gas.
Claim 28
Dependent Claim
63 words
The method according to claim 19, wherein said article is made of a material selected from the group consisting of silicon and tungsten, said etching gas is at least one member selected from the group consisting of F 2 , Cl 2 , SF 6 and NF 3 , and wherein said etching is one of reactive ion etching and microwave plasma etching.
References Cited (Backward Citations)
US3994793A
Cited
US4253907A
Cited
JPS5647569A
Cited
US4384918A
Cited
US4521275A
Cited
US4521275B1
Cited
NL8303458A
Cited
JPS59124135A
Cited
US4585668A
Cited
US4445966A
Cited
EP0133621A1
Cited
US4557796A
Cited
US4579623A
Cited
JPS60126835A
Cited
JPS60128621A
Cited
JPS60158627A
Cited
US4609428A
Cited
GB2171360A
Cited
JPS61283129A
Cited
US4615755A
Cited
US4943344A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1997-10-10 | 1998-04-11 | 1998-10-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-10-10 | 2002-04-11 | 2002-10-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-10-10 | 2006-04-11 | 2006-10-11 | $7700.00 | Window Closed / Lapsed |