Manufacture of semiconductor device

Abstract

Abstract PURPOSE:To remove heat treatment at a high temperature after emitter diffusion, and to control hFE with high accuracy by forming a gate oxide film and a passivation film in a MOS transistor before the process of the base diffusion and emitter diffusion of a bipolar transistor. CONSTITUTION:N-type buried regions 2 are shaped selectively to a P-type semiconductor substrate 1, and an N-type epitaxial layer 3 is grown. A gate oxide film 9 is grown, and an silicon nitride film 11 is grown. A P-type impurity 14 is introduced into the silicon substrate through the silicon nitride film 11 and the gate oxide film 9 in a region as an emitter. Ions are implanted only into an external base region 15 in a bipolar transistor and a source region 6 and a drain region 7 in a MOS transistor. Accordingly, one gate oxide film and a surface protective film are formed before an impurity region in the bipolar transistor is shaped, thus reducing the potentiality of exposure to severe heat treatment after the impurity is introduced.

Inventors

• 👤 Atsushi Kagizawa

Bibliographic Details