Proposal of Vertical-Channel Metal Oxide Semiconductor Field-Effect Transistor with Entirely Oxidized Silicon Beam Isolation

Abstract

A novel vertical-channel metal oxide semiconductor field-effect transistor (MOSFET) is successfully developed. This transistor features a highly self-aligned structure consisting of an active region, field oxide, and two sidewall gates. The active regions of silicon pillars and field oxides are formed in a straight silicon beam by the local oxidation of silicon (LOCOS). Subsequently, two sidewall gates are formed on a pillar as residues after controlled dry etching in a self-aligned manner. Since the two sidewall gates can control two different channels separately on one silicon pillar, two transistors are formed on the pillar. As the theoretical footprint of one pillar transistor is 4F2, the proposed oxidized silicon beam isolated vertical-channel transistor (OBI-VCT) has a potential application to 2F2-footprint transistors, where F is feature size.