Semiconductor device

Abstract

Abstract PURPOSE:To prevent wiring breakdown and to improve reliability, by constituting an interlayer insulating film by sequentially formed silicon oxide films, a silicon nitride film formed by a CVD method and a silicon oxide film. CONSTITUTION:On a semiconductor substrate 6, source and drain regions 5, a gate electrode 7 comprising polycrystalline silicon and an aluminum wiring 1 are formed. An interlayer insulating film between the gate electrode 7 and the aluminum wiring 1 is formed by a boron added phosphorus silicon oxide BPSG film 2A, a silicon nitride film 3 and a BPSG film 2. After a contact hole 9 is formed, heat treatment is performed at 950 deg.C. Then the upper BPSG film 2 is softened, and the contact hole 9 is smoothed. However, the shape of the lower BPSG film 2A is not collapsed owing to the presence of the silicon nitride film 3, which is not softened at high temperature. Since only the upper part of the contact hole is smoothed, the aluminum wiring 1 is not broken down. Thus the shape of the contact hole is made excellent, wiring breakdown can be prevented and reliability can be improved.

Inventors

• 👤 Akitoshi Saito
• 👤 斉藤　晃敏

Bibliographic Details