Insulated gate type semiconductor device

Abstract

Abstract PURPOSE:To make a parasitic transistor formed in a protecting element part small, and eliminate the restrictions of a semiconductor substrate by selecting necessary diodes of low breakdown strength among a plurality of junctions having different depths and impurity concentrations, and connecting them in series as the protecting element of an insulated gate type field effect transistor. CONSTITUTION:A DSA type MOS-FET 31 and diodes as a protecting element are formed on a common semiconductor substrate: two pairs of bi-directional connection diodes are connected in series between the source S and the gate G of the DSA type MOS-FET. According to this constitution, P<+> type regions 22, 23 of high surface concentration are deeply formed, so that hFE of a parasitic transistor can be made small. The breakdown strength of the diodes as a protecting element becomes a voltage VEB between emitter.base corresponding with the parasitic transistor, and the value is low. As a result, the manufacturing in response to the breakdown strength of the MOS-FET is enabled by connecting diodes of a plurality of constitutions in series.

Inventors

• 👤 Koji Takahashi
• 👤 孝司 高橋
• 👤 Shuichi Suzuki
• 👤 秀一 鈴木
• 👤 Satoo Komatsubara
• 👤 小松原　恵男

Bibliographic Details