ETCHING METHOD AND MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE
First Claim
1. An etching method of a substrate in which at least a silicon oxide film, a polysilicon film and a mask film having an opening are sequentially formed on a silicon base material, the method comprising:
- a polysilicon film etching process for etching the polysilicon film corresponding to the opening by using plasma generated from a processing gas containing an oxygen gas,wherein, in the polysilicon film etching process, an ambient pressure is set to be in a range from about 6.7 Pa to 33.3 Pa and a frequency of bias voltage for providing the plasma to the substrate is set to be equal to or more than about 13.56 MHz, so that the polysilicon film corresponding to the opening is etched.
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Accused Products
Abstract
Provided is an etching method capable of increasing a selectivity of a polysilicon film with respect to a silicon oxide film and suppressing the formation of recesses in a silicon base material. A wafer includes a gate oxide film, a polysilicon film and a hard mask film having an opening sequentially formed on a silicon base material, and has a native oxide film in a trench of the polysilicon film corresponding to the opening formed thereon. The native oxide film is etched, so that the polysilicon film is exposed at a bottom portion of the trench. An ambient pressure is set to be 13.3 Pa, and O2 gas, HBr gas and Ar gas are supplied to a processing space, and a frequency of bias voltage is set to be 13.56 MHz, so that the polysilicon film is etched by the plasma generated from the HBr gas to be completely removed.
29 Citations
8 Claims
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1. An etching method of a substrate in which at least a silicon oxide film, a polysilicon film and a mask film having an opening are sequentially formed on a silicon base material, the method comprising:
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a polysilicon film etching process for etching the polysilicon film corresponding to the opening by using plasma generated from a processing gas containing an oxygen gas, wherein, in the polysilicon film etching process, an ambient pressure is set to be in a range from about 6.7 Pa to 33.3 Pa and a frequency of bias voltage for providing the plasma to the substrate is set to be equal to or more than about 13.56 MHz, so that the polysilicon film corresponding to the opening is etched. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A semiconductor device manufacturing method for manufacturing a semiconductor device with a substrate in which at least a silicon oxide film, a polysilicon film and a mask film having an opening are sequentially formed on a silicon base material, the method comprising:
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a polysilicon film etching process for etching the polysilicon film corresponding to the opening by using plasma generated from a processing gas containing an oxygen gas, wherein, in the polysilicon film etching process, an ambient pressure is set to be in a range from about 6.7 Pa to 33.3 Pa and a frequency of bias voltage for providing the plasma to the substrate is set to be equal to or more than about 13.56 MHz, so that the polysilicon film corresponding to the opening is etched. - View Dependent Claims (8)
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Specification