JPS572578A - Junction type field effect transistor - Google Patents

Abstract

PURPOSE:To improve the withstand voltage of a field effect transistor without lowering Gm of the transistor by forming an ion injection region. CONSTITUTION:A junction type field effect transistor is composed of a P type silicon semiconductor substrate 21, an N type insular region 22, a P<+> type gate region 26 forming a channel region 25 by dividing the region 22 into source and drain regions 23 and 24, an N<-> type ion injection region 40, N<+> type source and drain contact regions 27, 28, an oxidized region 29, and source and drain electrodes 30, 31. When a depletion layer expanding toward the drain side of the region 26 reaches the region 40, it becomes ready to be expanded, and since it is expanded to an ion injected region 46 buried in the substrate 26, the concentration of the electric field is alleviated, and the withstand voltage between the gate and the drain can be improved.