Claims
- 1. 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.sup.4 .times.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.degree. c. or below, so as to substantially avoid etching of said sidewall portions due to neutral radicals in the plasma of the etching gas.
- 2. 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.sup.3 times the overall gas pressure.
- 3. 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.sup.2 times the overall gas pressure.
- 4. 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.
- 5. The method according to claim 1, wherein said etching is reactive ion etching.
- 6. The method according to claim 1, wherein said etching is microwave plasma etching.
- 7. The method according to claim 1, wherein said etching gas is at least one member selected from the group consisting of F.sub.2, Cl.sub.2, SF.sub.6 and NF.sub.3.
- 8. The method according to claim 1, wherein said article and said etching gas are tungsten and CF.sub.4, respectively, and said article is maintained at a temperature in the range from -5.degree. C. to -160.degree. C.
- 9. The method according to claim 8, wherein said article is maintained at a temperature in the range from -50.degree. C. to -160.degree. C.
- 10. The method according to claim 1, wherein said article and said etching gas are silicon and SF.sub.6, respectively, and said article is maintained at a temperature in the range from -95.degree. C. to '1145.degree. C.
- 11. The method according to claim 10, wherein said article is maintained at a temperature in the range from -130.degree. C. to -145.degree. C.
- 12. The method according to claim 1, wherein said article and said etching gas are silicon and CF.sub.4, respectively, and said article is maintained at a temperature in the range from -95.degree. C. to -190.degree. C.
- 13. The method according to claim 12, wherein said article is maintained at a temperature in the range from -130.degree. C. to '1190.degree. C.
- 14. The method according to claim 1, wherein the article and said etching gas are tungsten and SF.sub.6, respectively, and the article is maintained at a temperature in the range from -60.degree. to -150.degree. C.
- 15. The method according to claim 1, wherein the etching gas does not contain any carbon, boron or silicon.
- 16. The method according to claim 1, wherein the temperature of the article is at least 5.degree. 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.sup.4 times the overall gas.
- 17. 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.
- 18. 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.sub.2, Cl.sub.2, SF.sub.6 and NF.sub.3, and wherein said etching is one of reactive ion etching and microwave plasma etching.
- 19. 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.degree. C., so as to substantially avoid etching of said sidewall portions due to neutral radicals in the plasma of the etching gas.
- 20. The method according to claim 19, wherein said etching is reactive ion etching.
- 21. The method according to claim 19, wherein said etching is microwave plasma etching.
- 22. The method according to claim 19, wherein said etching gas is at least one member selected from the group consisting of F.sub.2, Cl.sub.2, SF.sub.6 and NF.sub.3.
- 23. The method according to claim 19, wherein the etching gas does not contain any carbon, boron or silicon.
- 24. The method according to claim 19, wherein the temperature of the article is at least 5.degree. C. above said temperature at which the vapor pressure of said etching gas molecules becomes equal to the overall gas pressure and below -95.degree. C.
- 25. 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.
- 26. 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.sub.2, Cl.sub.2, SF.sub.6 and NF.sub.3, and wherein said etching is one of reactive ion etching and microwave plasma etching.
Priority Claims (2)
Number |
Date |
Country |
Kind |
61-207832 |
Sep 1986 |
JPX |
|
62-99739 |
Apr 1987 |
JPX |
|
Parent Case Info
This application is a continuation of U.S. patent application Ser. No. 07/302,123, filed Jan. 26, 1989, now abandoned, which is a continuation of U.S. patent application Ser. No. 084,806, filed Aug. 13, 1987, now abandoned.
US Referenced Citations (11)
Foreign Referenced Citations (9)
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Date |
Country |
0133621 |
Mar 1985 |
EPX |
56-47569 |
Apr 1981 |
JPX |
59-124135 |
Jul 1984 |
JPX |
60-126835 |
Jul 1985 |
JPX |
60-128621 |
Jul 1985 |
JPX |
60-158627 |
Aug 1985 |
JPX |
61-283129 |
Dec 1986 |
JPX |
8303458 |
May 1984 |
NLX |
2171360 |
Aug 1986 |
GBX |
Non-Patent Literature Citations (3)
Entry |
Bensaoula et al., "Low-temperature ion beam enhanced etching of tungsten films with xenon difluoride", Appl. Phys. Lett. 49(24), Dec. 15, 1986, pp. 1663-1664. |
Parrens, "Anisotropic and Selective Reactive Ion Etching of Polysilicon Using SF.sub.6 " J. Vac. Sci. Technol., 19(4) pp. 1403-1407, Nov./Dec. 1981. |
Schaible et al., "Reactive Ion Etching of Aluminum and Aluminum Alloys", IBM TDB, vol. 21, No. 4, p. 1468, Sep. 1978. |
Continuations (2)
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Number |
Date |
Country |
Parent |
302123 |
Jan 1989 |
|
Parent |
84806 |
Aug 1987 |
|