GATE DEMARCATION TRANSISTOR

PURPOSE: To provide the transistor having the gate structure, wherein the dimensions of a channel are not affected by the intruding degree of a field oxide into the channel region of a bird's beak structure. CONSTITUTION: A gate conductor 42 covers a gate oxide layer 70 at the central part and a lower channel region 50, and covers field oxide layers 72 and 74 including bird's beak structures 76 and 78 at both outer parts. The conductance of a channel region 50 is electrically controlled. The conductor 42 is photolithographically patterned so as to include notches 60 and 62 in proximity with the channel region 50, and the effective channel length and width are determined. As a result, the current conducting capability of a transistor 40 is determined not by the intruding degrees of the bird's beak structures 76 and 78 into the channel region but by the gate conductor 42 and the notches 60 and 62.