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US 7,404,910 B1Granted
Etching solution, etched article and method for etched article
AssigneeDaikin Industries, Ltd.
InventorsTakehiko Kezuka, Makoto Suyama, Mitsushi Itano
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Abstract
An etching solution which contains hydrogen fluoride (HF) and exhibits an etching rate ratio: etching rate for a boron-glass film (BSG) or boron-phosphorus-glass film (BPSG)/etching rate for a thermally oxidized film (THOX) of 10 or more at 25° C.
Claims8
An etching solution consisting essentially of:
- (i) hydrofluoric acid;
- (ii) water in a concentration of 30% by weight or lower;
- and
- (iii) at least one member selected from the group consisting of an organic acid, an inorganic acid having a pKa at 25° C. of about 2 and an organic solvent having a hetero atom, whose content ranges from 70 to 99.9% by weight, wherein the etching solution has a ratio of an etch rate of a boron silicate glass film (BSG) or boron phosphosilicate glass/an etch rate of a thermal oxide film (THOX) at 25° C. of 20 or higher.
1 more element
Dependencies are inferred from the claim text.