TRANSISTOR HAVING IMPROVED SOI BODY CONTACT STRUCTURE

PROBLEM TO BE SOLVED: To obtain a 'BC' type body contact SOI transistor and its manufacture. SOLUTION: An overlapping tolerance is eliminated from an effective transistor width. The width is decided by RX at the upside but by PC at the downside, (the abbreviation PC devotes a shape of a polysilicon structure). In a preferred embodiment, by using a structure comprising an upper part of an SOI transistor and a lower part of a mirror image with respect to the upper part, influences by overlapping PC/RX are made quite contrary to each other. The upper part is connected to the lower part by a common body region 212. In the lower part, misalignment to an 'upward direction' increases a device width, and misalignment to a 'downward direction' decreases a device width. Accordingly, if the PC is misaligned to RX, (which denotes a shape representing an opening of a field oxide exposing active silicon), a deviation in the width in the upper part of transistors is accurately cancelled by the lower part of the transistors.