Claims
- 1. A method of anisotropically etching a high aspect ratio, straight walled opening in silicon, said opening having a rounded bottom which comprises:
- a) forming a plasma from a precursor gas etch mixture of HI as the main etchant, oxygen to provide protection for the sidewalls of the openings and to control selectivity with respect to an oxide etch mask and chlorine.
- 2. A method according to claim 1 wherein said silicon is a single crystal silicon body.
- 3. A method according to claim 1 wherein said silicon is a polycrystalline silicon layer.
- 4. A method according to claim 1 wherein the precursor gas etch mixture further includes a fluorine-containing gas.
- 5. A method according to claim 4 wherein the fluorine-containing gas is silicon tetrafluoride.
- 6. A method according to claim 1 wherein the precursor gas etch mixture further includes silicon tetrachloride.
- 7. A method according to claim 1 wherein said plasma is generated in the presence of a magnetic field parallel to the surface of said silicon.
- 8. A method according to claim 1 wherein said precursor gas etch mixture further includes a diluent.
- 9. A method according to claim 7 wherein said diluent is helium.
- 10. A method according to claim 1 wherein said aspect ratio is at least about 10:1.
Parent Case Info
This application is a divisional of application Ser. No. 08/639,411 filed Apr. 29, 1996, U.S. Pat. No. 5,874,362, which is a continuation of application Ser. No. 08/229,863 filed Apr. 19, 1994, now abandoned, which is a continuation of application Ser. No. 07/855,124 filed Mar. 18, 1992, now abandoned, which is a continuation of Ser. No. 07/709,809 filed May 31, 1991, now abandoned, which is a continuation of Ser. No. 07/587,523 filed Sep. 21, 1990, now abandoned, which is a continuation of Ser. No. 07/363,429 filed Jun. 5, 1989, now abandoned, which is a continuation of Ser. No. 07/251.928 filed Sep. 29, 1988, now abandoned, which is a continuation of Ser. No. 06/944,491 filed Dec. 19, 1986, now abandoned.
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Divisions (1)
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639411 |
Apr 1996 |
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Continuations (7)
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229863 |
Apr 1994 |
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855124 |
Mar 1992 |
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709809 |
May 1991 |
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587523 |
Sep 1990 |
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363429 |
Jun 1989 |
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251928 |
Sep 1988 |
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944491 |
Dec 1986 |
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