Vertical field-effect transistor

Abstract

Abstract PURPOSE: To improve breakdown strength and to improve operating speed, by providing An additional region, which has a reverse conductivity type with respect to a drain region and is not in contact with a base region, in the drain region at the intermediate position in the diagonal direction of neighboring base regions. CONSTITUTION: An intermediate position, i.e., a point A, is located in the diagonal direction of neighboring base regions 3 and directly beneath a mesh shaped gate electrode 5. An ion implanted impurity layer, which has a reverse conductivity type with respect to a drain region 2, is formed in said N - drain region 2 at the point A in the main surface of the N - drain region 2. Said layer is constituted as an electric field alleviating layer 8. In a vertical type field effect transistor having said constitution, the yield of part, where base-to-base interval is larger than the interval between the neighboring base region 3, can be prevented. Thus, the base-to-base interval is made uniform to the optimum base-to-base interval. The breakdown strength of the field effect transistor is kept at breakdown strength, which is determined with the optimum base-to- base interval. COPYRIGHT: (C)1989,JPO&Japio

Inventors

• 👤 Yoshitomo Takahashi

Bibliographic Details