Manufacture of mos type semiconductor device

Abstract

Abstract PURPOSE:To prevent the punch-through of B as well as to stably obtain a P type Si gate MOSFET by a method wherein an oxygen unpermeative film is provided on a poly Si film alone and a B-ion is implanted thereon. CONSTITUTION:A poly Si film 9 and an Si3N4 or an Al2O3 film 10 are superposed on a gate oxide film 8, a selective etching is performed, the oxygen unpermeative film 10 is left on a poly Si gate electrode 9, and when a B-ion implantation is performed on a poly Si layer 9, an N type Si substrate 6 is provided at the same time. According to this constitution, the punch-through of B is hardly generated even when a heat treatment is performed in O2 or vapor. There is a possibility of dissolving of B into an SiO2 film with O2 infiltrated from the side face of the layer 9, but the distance thereof is sufficiently short when compared with the gate length, and no influence is infricted on the FET characteristics at the center part of the gate, thereby enabling to manufacture the desired P type Si gate MOSFET is stabilized.

Inventors

• 👤 Yasuo Ono
• 👤 泰夫 大野

Bibliographic Details