A dry etching gas comprising a C
4-6
fluorine compound which has an ether bond or carbonyl group and one or more fluorine atoms in the molecule and is constituted only of carbon, fluorine, and oxygen atoms and in which the ratio of the number of fluorine atoms to the number of carbon atoms (F/C) is 1.9 or lower (provided that the compound is neither a fluorine compound having one cyclic ether bond and one carbon-carbon double bond nor a saturated fluorine compound having one carbonyl group); a mixed dry etching gas comprising the dry etching gas and at least one gas selected from the group consisting of rare gases, O
2
, O
3
, CO, CO
2
, CHF
3
, CH
2
F
2
, CF
4
, C
2
F
6
, and C
3
F
8
; and a method of dry etching which comprises converting either of these dry etching gases into a plasma and processing a semiconductor material with the plasma. The dry etching gases can be safely used, are reduced in influence on the global environment, and can highly selectively dry-etch a semiconductor material at a high dry etching rate to form a satisfactory pattern shape. The dry etching method employs either of these dry etching gases.
一种干法刻蚀气体,包括C4-6
氟化合物,其具有醚键或羰基基团和分子中的一个或多个
氟原子,仅由碳、
氟和氧原子构成,其中
氟原子与碳原子的比例(F/C)为1.9或更低(前提是该化合物既不是具有一个环状醚键和一个碳-碳双键的
氟化合物,也不是具有一个羰基基团的饱和
氟化合物);混合干法刻蚀气体包括干法刻蚀气体和至少一种选自稀有气体、O2、O3、CO、
CO2、
CHF3、
CH2F2、
CF4、
C2F6和
C3F8的气体的气体;以及一种干法刻蚀方法,包括将这些干法刻蚀气体之一转化为等离子体,并用等离子体处理半导体材料。这些干法刻蚀气体可以安全使用,对全球环境的影响减少,并且可以高度选择性地干法刻蚀半导体材料以形成令人满意的图案形状。这种干法刻蚀方法采用这些干法刻蚀气体之一。