Method of forming conductive layers in the trenches or through holes made in an insulating film on a semiconductors substrate

Abstract

Conductive layers are formed in the trenches made in an insulating film in the following manner. First, an amorphous silicon film A is deposited in the trenches made in a silicon oxide film A photoresist film is then formed on the amorphous silicon film A by means of spin coating. Then, exposure light is applied to the entire surface of the photoresist film thereby exposing to light those parts of the photoresist film 30 which lie outside the trenches The other parts of the photoresist film which lie in the trenches are not exposed to light because the light reaching them is inadequate. Further, the photoresist film is developed thereby removing those parts of the film which lie outside the trenches and which have been exposed to light. Thereafter, those parts of the amorphous silicon film A, which lie outside the trenches are removed by means of dry etching using, as a mask, the unexposed parts of the photoresist film which remain in the trenches