Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To decrease an electric field in the vicinity of a drain, to decrease impact ionization, to prevent kink in a thin film SOIMOSFET, and to make it possible to suppress the decrease in breakdown strength, by offsetting a gate electrode and source and drain regions. CONSTITUTION:A CVD oxide film 2 and a polycrystalline silicon film 3 are sequentially deposited on a single crystal silicon substrate 1. The polycrystalline silicon film 3 is made to be a single crystal film by laser beam annealing technology and the like. Then, B ions are implanted, and the film is made to be a p-type SOI layer. Thermal oxidation is further performed. A gate oxide film 4 is formed. Then, a polycrystalline film 5 is deposited. A gate is formed by patterning. Then, a CVD oxide film 7 is deposited. Etching is performed by RIE. The CVD film is made to remain on the side wall of the gate. Thereafter, As ions are implanted, and source and drain regions 6 are formed. The gate electrode 5 and the drain layer 6 are offset. Thus an electric field in the vicinity of the drain can be decreased. As a result, impact ionization is weakened, and the generation of kink of current and voltage characteristics can be suppressed.

Inventors

• 👤 Naoyuki Shigyo

Bibliographic Details