Oki Electric Industry Co., Ltd.

Hiroshi Hoga

Kimiaki Shimokawa

An insulating film formed under a conductive film has a side wall defining a contact window and having the shape of a gently inclined curvilinear surface, so that the insulating film is able to provide a sufficient step coverage in the contact window. The insulating film is formed over the surface of a semiconductor substrate or a first conductive film. The insulating film has an increasing or decreasing refractive index over the depth thereof. A contact window is formed by selectively removing a portion of the insulating film using a photoresist pattern formed over the surface of the insulating film. A structure thus formed is subjected to an etching process capable of etching the upper layer of the insulating film at an etching rate higher than that for the lower layer of the same to etch the side wall of the insulating film defining the contact window into a gently inclined curvilinear surface, and then the photoresist pattern is removed. A second conductive film is formed over the surface of a structure formed in the preceding step.

Process for manufacturing a semiconductor device having a contact window

A method of manufacturing a semiconductor substrate having dielectric regions is disclosed. The method comprises steps of forming an amorphous silicon layer on the surface of a monocrystalline silicon substrate, annealing a selected surface of said amorphous silicon layer to form a crystallized region intended as an active region, subjecting the obtained structure to a thermal oxidation process to form said dielectric isolation regions, and removing an oxide coating formed on the surface of said crystallized region.

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Tokyo, Japan

Hiroshi Hoga