JPS57141936A - Semiconductor device - Google Patents

Abstract

PURPOSE:To prevent the breaking of wire of the underlayer wiring to be connected and to obtain high reliability for the subject semiconductor device by a method wherein an insulating film, consisting of a metal compound to be provided on an underlying wiring, is formed in such a manner that a metal ingredient will gradually become low-densed as it approached the upper part of the wiring, and the section of a contact hole is formed in a cone shape. CONSTITUTION:For example, an underlying wiring layer 22 is formed on a GaAs substrate 21, and a nitride film 23 is formed on the wiring layer 22 by decompression CVD method using SiH4/NH3 reaction gas, for example. The nitride film 23 is deposited in such a manner that the density of an Si ingredient will be gradually reduced as it approaches the upper part by slowly reducing the quantity of flow of SiH4, for example. Then, a photoetching is performed on a contact hole 24 using a resist film 27, for example, as a mask, subsequently resist film 27 is removed, and the wirings are connected by providing an upperlayer wiring. Accordingly, the shape of the section of the contact hole 24 can be formed into a gently-sloped cone shape, and the trouble casued by the breaking of wire and the like of the wirings on the upper layer can be prevented.