PROCESS FOR MAKING POLYCIDE STRUCTURES

摘要

On an insulating layer (12) a polysilicon layer (14) and a silicide layer (22) are deposited and by a lift-off technique a dry etching mask (28) is formed of a metal being not eroded during the dry etching and being removable by wet etching with etchants that do not etch the underlying material, and at least the areas of the polysilicon layer (14) not covered by dry etching mask (28) are removed by dry etching.
The silicide layer (22) may be deposited either through a chemical vapor deposition process or through the co-deposition of a silicide forming metal and silicon followed by a low temperature annealing step prior to dry etching. To avoid in said latter case a diffusion of the metal mask into the underlying material during this low temperature annealing, the process provides for the formation of a diffusion barrier layer (22) between the dry etching metal mask (28) and the underlying material. The polycide structures are used for electrode and wiring interconnection applications.