METHOD FOR FABRICATING TRANSISTOR OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a transistor of a semiconductor device is provided which can obtain a desired switching effect in the device by preventing the reduction of a threshold voltage by assuring a sufficient channel region. CONSTITUTION: According to the method, a sufficient channel length is obtained by forming a source/drain region(26) with one process, and by forming a gate electrode(30A) by burying a trench with a conductive layer after forming the trench deeply between the source/drain region. A well region(24) is formed by implanting a low dense impurity ion into a semiconductor substrate(21), and the source/drain region is formed by ion implantation of a high dense impurity selectively on the well region. The trench is formed by etching the semiconductor substrate between the source/drain region. And the conductive layer is formed to bury the trench after forming a gate oxide(29) on the whole top structure including the trench. And, finally, the gate electrode is formed in the trench by blanket etching of the conductive layer and the gate oxide.