Claims
- 1. Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide formed on a wafer, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from a mixture of trifluoromethane and ammonia gases,
- said chamber including surfaces exposed to said plasma,
- and a coating of silicon on at least the surfaces in the immediate vicinity of said layer to be etched.
- 2. An apparatus as in claim 1 wherein said coating comprises individual particles of monocrystalline or polycrystalline silicon fused together on said surfaces in a plasma spraying process.
- 3. An apparatus as in claim 2 further including a cathode electrode in said reaction chamber,
- and means mounting said wafer on said cathode electrode.
- 4. An apparatus as in claim 3 wherein said establishing means includes means for establishing the following conditions in said reaction chamber: a pressure of approximately 50 micrometers, a power density of approximately 0.16 watts per square centimeter at the surface of the layer to be etched, a gas flow into said chamber of approximately 96 volume percent trifluoromethane and 4 volume percent ammonia, a gas flow into said chamber of approximately 30 cubic centimeters per minute and a dc bias voltage of said cathode electrode with respect to a point of reference potential of approximately 600 volts.
- 5. Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide on a wafer that is to be processed to form multiple integrated circuits, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from a mixture of trifluoromethane and ammonia,
- means within said chamber for holding a number of wafers to be etched,
- said chamber having internal surfaces including surfaces of said holding means in the immediate vicinity of said wafers to be etched,
- and a coating of silicon formed on internal surfaces including at least the surfaces of said holding means in the immediate vicinity of said wafers.
- 6. A method for fabricating VLSI devices by delineating fine-line patterns in a layer of silicon dioxide on a wafer in accordance with a process sequence that includes low-contamination plasma-assisted dry etching, said method comprising the steps of
- mounting said wafer to be etched in a reaction chamber at least some of whose surfaces, including surfaces in the immediate vicinity of said layer to be etched, are coated with a layer of silicon,
- introducing a mixture of trifluoromethane and ammonia gases into said reaction chamber,
- and establishing an etching plasma within said chamber.
- 7. A method as in claim 6 wherein a cathode electrode is included in said reaction chamber and said wafer to be etched is mounted on said cathode electrode.
- 8. A method as in claim 7 wherein said establishing step includes establishing the following conditions in said reaction chamber: a pressure of approximately 50 micrometers, a power density of approximately 0.16 watts per square centimeter at the surface of the layer to be etched, a gas flow into said chamber of approximately 96 volume percent trifluoromethane and 4 volume percent ammonia, a gas flow into said chamber of approximately 30 cubic centimeters per minute and a dc bias voltage of said cathode electrode with respect to a point of reference potential of approximately 600 volts.
- 9. Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide formed on a water, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from trifluoromethane,
- said chamber including surfaces exposed to said plasma,
- and a coating of silicon on at least the surfaces in the immediate vicinity of said layer to be etched.
- 10. An apparatus as in claim 9 wherein said coating comprises individual particles of monocrystalline or polycrystalline silicon fused together on said surfaces in a plasma spraying process.
- 11. An apparatus as in claim 10 further including a cathode electrode in said reaction chamber,
- and means mounting said wafer on said cathode electrode.
- 12. Apparatus for low-contamination plasma-assisted dry etching of a layer of silicon dioxide on a wafer that is to be processed to form multiple integrated circuits, said apparatus comprising
- a reaction chamber,
- means for establishing within said chamber an etching plasma derived from trifluoromethane,
- means within said chamber for holding a number of wafers to be etched,
- said chamber having internal surfaces including surfaces of said holding means in the immediate vicinity of said wafers to be etched,
- and a coating of silicon formed on internal surfaces including at least the surfaces of said holding means in the intermediate vicinity of said wafers.
- 13. A method for fabricating VLSI devices by delineating fine-line patterns in a layer of silicon dioxide on a wafer in accordance with a process sequence that includes low-contamination plasma-assisted dry etching, said method comprising the steps of
- mounting said wafer to be etched in a reaction chamber at least some of whose surfaces, including surfaces in the immediate vicinity of said layer to be etched, are coated with a layer of silicon,
- introducing trifluoromethane gas into said reaction chamber,
- and establishing an etching plasma within said chamber.
- 14. A method as in claim 13 wherein a cathode electrode is included in said reaction chamber and said wafer to be etched is mounted on said cathode electrode.
Parent Case Info
This application is a continuation of application Ser. No. 295,650, filed Aug. 24, 1981, now abandoned.
US Referenced Citations (3)
Foreign Referenced Citations (2)
Number |
Date |
Country |
54-14679 |
Mar 1979 |
JPX |
54-162269 |
Dec 1979 |
JPX |
Continuations (1)
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Number |
Date |
Country |
Parent |
295650 |
Aug 1981 |
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