Semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To keep the low value of a substrate current ISUB under the state an electric field is gentle in the vicinity of an interface between a low impurity concentration region and an insulating film even if a device is used for a long time, by selectively growing a metal material to be struck on a part on a low impurity concentration layer in order to reduce the resistance of a gate electrode. CONSTITUTION:After polycrystalline Si film 24 is etched in a previous step, e.g., As ions are implanted into the entire surface. A low impurity concentration layer 26 is formed in a substrate 21. After resist 25 is removed, e.g., a W metal film 27 is deposited on the entire surface. Then, e.g., a resist film 28 is applied on the entire surface of a resist insulating film 28. Thereafter, the insulating film 28 is made to remain on the side wall part of the Si film 24 by RIE. With the insulating film 28 as a mask, the thin W metal film 27 is etched. Then, the insulating film 28 is removed. Under the state the pressure of WF6 gas and H2 gas is reduced, a W metal film 29 is formed only on the Si film 24 and the W metal film 27 by a CVD method. With the Si film 24 and the W metal film 27 and 29 as masks, e.g., As ions are implanted into the substrate, and a high impurity concentration layer 30 is formed. Thereafter, thermal oxidation is performed in an oxidizing atmosphere, and the intended MOSFET is completed.

Inventors

• 👤 Masamizu Konaka

Bibliographic Details