MOS TRANSISTOR HAVING CHANNEL WITH RELATIVELY LARGER LENGTH THAN THAT OF CONVENTIONAL CHANNEL WITHOUT DEGRADATION OF INTEGRATION DEGREE AND MANUFACTURING METHOD THEREOF

摘要

PURPOSE: An MOS(Metal Oxide Semiconductor) transistor and a manufacturing method thereof are provided to secure a large process margin on the controllability of leakage current and off-current by obtaining a relatively large length from a channel compared to a conventional channel without the degradation of integration degree using an epitaxial layer. CONSTITUTION: A gate trench for exposing selectively a semiconductor substrate(11) to the outside is formed in a sacrificial layer. The gate trench is partially filled with an epitaxial layer(14) and a gate oxide layer(15). At this time, the epitaxial layer is used as a channel region. A polycrystalline silicon layer(16) for filling completely the gate trench is formed thereon and planarized. The sacrificial layer is removed therefrom. A protective layer(17) is formed on the entire surface of the resultant structure.