METHOD OF FORMING ELECTRICAL INTERCONNECTION PART IN SILICON SEMICONDUCTOR DEVICE

摘要

PURPOSE: To obtain a method where an etching operation of a contact opening part is not critical and a contact between a semiconductor material and a layer of a silicide are maintained as it is by covering a contact island with a supplementary metallic layer obtained through selective growing of a tungsten or a molybdenum before a separation layer is formed. CONSTITUTION: A layer of an ultrahigh heat-resistance metal such as a titanium is depositted on an entire structure, then the titanium layer is reacted on a silicon surface part not covered by a dielectric layer 19 through a proper heat processing to form a titanium silicide to a part of a contact region 18 and finally the remaining part of the unreacted titanium layer is removed through selective etching so as to be self-aligned with the contact region 18 in a contact island 20. Then the tungsten is selectively grown to cover the contact island 20 with a comparatively thin supplementary metallic layer. A titanium nitride layer 202 acts like a core forming base with respect to the growing of the tungsten during this processing and the dielectric layer 19 hinders this growing on the other hand. Thus, the supplementary metallic layer 30 is placed on the contact island 20 without the need for the any photo-mask operation.