Semiconductor device on SOI substrate

Claim 1

A semiconductor device, comprising: a SOI substrate including a handling wafer, a buried insulating layer formed on the handling wafer and a silicon layer of a first conductivity type, formed on the buried insulating layer, wherein the silicon layer consists of a first and second portions , and the first portion is thicker than the second portion so that the silicon layer has a stepped portion between the first and second portions; a gate electrode formed on the silicon layer including the stepped portion; a gate insulating layer formed between the gate electrode and the silicon layer; a first junction region of a second conductivity type opposite to the first conductivity type, formed on the first portion of the silicon layer, wherein bottom of the first junction region is positioned at a selected depth from the surface of the first portion of the silicon layer; a second junction region of the second conductivity type, formed on the second portion of the silicon layer at a selected depth from the surface of the second portion of the silicon layer; an intermediate insulating layer formed on the overall surface of the SOI substrate including the gate electrode, and the first and second junction regions; a first conduction line formed on the intermediate insulating layer, an extending portion of the first conduction line being extended to the bottom of the first junction region through the intermediate insulating layer and the underlying first junction region; and a second conduction line formed on the intermediate insulating layer, an extending portion of the second conduction line being extended to the upper surface of the second junction region.