Mis type semiconductor device and manufacture thereof

Abstract

Abstract PURPOSE:To relax a concentration of an electric field at the end of a drain and prevent a phenomenon of hot carriers being implanted by forming an inverse T-shaped gate structure using metallic layers of high melting point being formed on the surface of the gate electrode and on the insulating film of the side face thereof. CONSTITUTION:A gate oxide film 3 is formed newly in the region surrounded with a LOCOS oxide film 2 which is formed on the surface of a p-type silicon substrate 1. Then, a polysilicon is deposited on the gate insulating film 3, and a gate insulating electrode 4 is formed. By introducing (P) into the surface side part of the substate 1 through the method of implanting ions using the gate electrode 4 as a mask, n<->-type regions 5a, 6a of low concentration are formed. A Ti layer 11 is stuck on the whole face of the surface side of the silicon substrate 1 by sputtering. Thereafter, the silicon substrate 1 is subjected to a heat treatment in the atmosphere of nitrogen. Thereafter, an oxide film 12 is deposited by a thermal CVD method. By etching the oxide film 12 through a RIE method and removing the resultant, a sidewall insulating film 12a is formed on the side face of the gate electrode 4. A nitriding layer 21, which is generated together with the oxide film 12, is removed using an etching gas including (F) in a single process. As ions are implanted into the surface side part of the silicon substrate 1, and n<+>-type source region 5 and a drain region 6 are formed.

Inventors

• 👤 Toshihiko Kondo
• 👤 俊彦 近藤

Bibliographic Details