| 摘要 |
PROBLEM TO BE SOLVED: To etch an interlayer insulation film that is composed of organic film made mainly of organic constituent without oxidizing the interlayer insulation film. SOLUTION: An interlayer insulation film which is made mainly of organic constituent such as polyaryl ether derivative or polyparaxylene or the like, is piled up on a semiconductor substrate. Next, the interlayer insulation layer is etched by a plasma containing an etching gas made mainly of ammonia gas. Thus, an active hydrogen is produced in the plasma containing ammonia gas, and the active hydrogen dissolves the organic constituent into hydrogen cyanide, progressing etching. Since the surface of the organic film is efficiently nitrided by nitrogen generated from the ammonia gas, the side wall of a recessed part in the organic film is protected and high anisotropy can be realized. In addition, since the etching gas does not contain any component oxidizing organic films, a trouble that gas is produced in the organic film does not occur in the following heat treatment step.
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