Semiconductor device fabrication method
AssigneeOki Electric Industry Co., Ltd.
InventorShogo Komagata
Life of this patent
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Abstract
During etching of a BARC film, etching gas is used in which O2, Cl2 and He are mixed in appropriate flow volume ratios, and an appropriate ion energy is set. Thus, a selectivity ratio with respect to an underlying film, which is a SiN film, can be sufficiently assured and a pattern is formed uniformly. During etching of a SiN film, etching gas is used in which HBr, CH4 and He are mixed in appropriate flow volume ratios, and an appropriate ion energy is set. Thus, the form of a pattern is consistent regardless of high- and low-density portions.
Claims15
A semiconductor device fabrication method including etching a BARC film disposed with an underlying SiN or polySi film, the etching comprising:
- dry-etching the BARC film with etching gas in which at least O2, Cl2 and He are mixed with predetermined flow volume ratios;
- and
- when an etching selectivity ratio of the BARC film relative to the underlying film is to be made larger, increasing the flow volume ratio of O2 relative to Cl2.
A semiconductor device fabrication method including etching a BARC film disposed with an underlying SiN or polySi film, the etching comprising:
- dry-etching the BARC film with etching gas in which at least O2, Cl2 and He are mixed with predetermined flow volume ratios;
- and
- when an etching selectivity ratio of the BARC film relative to the underlying film is to be made larger, reducing ion energy at the time of etching.
A semiconductor device fabrication method including etching a BARC film disposed with an underlying SiN or polySi film, the etching comprising:
- dry-etching the BARC film with etching gas in which at least O2, Cl2 and He are mixed with predetermined flow volume ratios;
- and
- setting the flow volume ratio of O2 relative to Cl2 in the etching gas to at least 1.
A semiconductor device fabrication method including etching a SiN film, the etching comprising:
- at the time of etching the SiN film, using etching gas in which HBr, CF4 and He are mixed in predetermined flow volume ratios;
- and
- setting ion energy at the time of etching in a range from 13 eV to 30 eV.
Dependencies are inferred from the claim text.