Preparation of semiconductor device

Abstract

Abstract PURPOSE:To obtain a semiconductor device with less fluctuation of surface impurity concentration of impurity diffused layer and unified characteristics, by executing a heat processing at a low temperature before forming diffused impurity layer in the semiconductor substrate by a high temperature heat processing. CONSTITUTION:A PSG film 14 is formed by the following steps, namely, a P<-> layer 12 is formed by the epitaxial growth method on a P type silicon substrate 11, an N type liquid phase diffused impurity source 13 is coated, heat processing is carried out under the atmospheric condition at a temperature of 140-160 deg.C in order to vaporize a solvent of alcohol system, moreover heat processing is carried out under the nitrogen atmosphere at a temperature of 290-350 deg.C in order to prevent generation of gas by perfect combustion of unwanted materials for synthesis of sources. An N<+> layer 15 is formed by deposition under the nitrogen atmosphere at a temperature of 900 deg.C or higher and an oxide film 16 is formed under the acidic atmosphere. A base layer (N<-> layer) 17 having the specified diffusion depth is formed by diffusion under a temperature of 1,200 deg.C.

Inventors

• 👤 Kiyoshi Wakashima
• 👤 若島　清
• 👤 Shoichi Kitane
• 👤 北根　正一

Bibliographic Details