Field effect transistor and manufacture of the same

Abstract

Abstract PURPOSE:To neutralize a negative potential by a positive voltage applied to a gate electrode even if hot electrons are trapped by an insulating film by a method wherein a gate electrode of a T-shape cross-section is formed on a required part of a substrate and the insulating film is buried between the part of the gate electrode close to the substrate surface and the substrate surface beneath the electrode. CONSTITUTION:After a gate insulating film 2 is formed on a silicon substrate 1, the material for a gate electrode 3 is applied. The gate electrode material is a double-layer film composed of, for instance, a polycrystalline silicon layer 3a and a high melting point metal layer 3b. By applying plasma etching to the electrode materials 3a and 3b with optimized conditions such as gas composition, gas pressure and electric power, a gate electrode 3 of a T-shape cross-section which has a brim part is formed. Then low concentration diffused layers 4 are provided closer to the gate electrode than high concentration diffused layers 6 and those two type diffused layers form continuous double-layer structures. With this constitution, a highly reliable transistor in which creation of hot carriers is suppressed and the gm deterioration caused by the carriers trapped by the insulating film is avoided can be obtained.

Inventors

• 👤 Shinichi Sato
• 👤 真一 佐藤

Bibliographic Details