| 摘要 |
PURPOSE:To make it possible to form grooves different in depth by one time of an REP method and a mask pattern by a method wherein wider and narrower grooves having the same depth are formed in a substrate and in the case of the wider groove, a poly Si film remaining on the side surface is oxidized by performing an anisotropic etching to convert into a second insulating film and this is used as a mask for forming the deeper groove. CONSTITUTION:Two kinds or more of grooves, which are different in width, are formed in a desired depth by etching using an oxidation-resisting masking material 2 deposited on a semiconductor substrate 1 as a mask and thereafter, a first oxide film 4 is formed on the side surfaces and bottom surfaces of the grooves. After an oxidation-resistant film 5 is deposited covering this, a poly Si film 6 is deposited on the whole region in a degree that the narrower groove is completely filled. Then, this poly Si film 6 is vertically etched to exposed the oxidation-resistance film 5 on the bottom surface of the wider groove and the poly Si film 6 remaining on the side surface part is converted into an oxide film 7. Then, the oxidation-resistant film 5 and the oxide film 4 on the bottom part of the groove are etched away using this oxide film 7 as a mask to expose the substrate 1 and the exposed place is subjected to anisotropic etching to form a deep groove 8. The surface thereof i covered with an oxide film 9 and thereafter, when such a filler 10 as poly Si is deposited to fill the wider groove, the deeper groove and the shallower groove can be finally obtained by one time of an REP method. |
