EP0195477A2
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Method of manufacturing a semiconductor device, in which a double layer - consisting of poly Si and a silicide - present on a layer of silicon oxide is etched in a plasma
Abstract A method of manufacturing a semiconductor device, in which a double layer (12) consisting of a layer of polycrystalline silicon (13) and a top layer of a silicide (14) is applied to a surface (11) of a semiconductor substrate (6) coated with a layer of silicon oxide (10). After an etching mask (15) has been provided, the double layer (12) is etched in a plasma formed in chlorine gas to which up to 20 % by volume of tetrachloromethane is added until the layer of polycrystalline silicon is etched. Thus, the double layer (12) is etched anisotropically and the layer of silicon oxide (10) is attacked in practice to a very small extent.
1 . A method of manufacturing a semiconductor device, in which a double layer consisting of a layer of polycrystalline silicon and a top layer of a silicide is applied to a surface of a semiconductor substrate coated with a layer of silicon oxide, after which the double layer, after having been provided with an etching mask, is locally etched away from the silicon oxide layer in a chlorine-containing etching plasma, characterized in that the etching plasma is formed in chlorine gas, to which up to 20 % by volume of tetrachloromethane is added until the layer of polycrystalline silicon is etched.
Claim 2
Dependent Claim
102 words
1 . A method of manufacturing a semiconductor device, in which a double layer consisting of a layer of polycrystalline silicon and a top layer of a silicide is applied to a surface of a semiconductor substrate coated with a layer of silicon oxide, after which the double layer, after having been provided with an etching mask, is locally etched away from the silicon oxide layer in a chlorine-containing etching plasma, characterized in that the etching plasma is formed in chlorine gas, to which up to 20 % by volume of tetrachloromethane is added until the layer of polycrystalline silicon is etched.
Claim 3
Dependent Claim
36 words
A method as claimed in Claim 1, characterized in that, after the addition of tetrachloromethane to the chlorine gas has been stopped, up to 10 % by volume of hydrogen is added to the chlorine gas.
Claim 4
Dependent Claim
22 words
A method as claimed in Claim 1 or 2, characterized in that the silicide layer consists of molybdenum silicide or tungsten silicide.
Claim 5
Independent Claim
31 words
A method as claimed in any one of the preceding Claims, characterized jnthat the etching plasma is produced by an electromagnetic alternating field having a frequency of 50 to 500 kHz.
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