| 摘要 |
<P>PROBLEM TO BE SOLVED: To sufficiently retreat a shoulder of a trench, to sufficiently round a corner, to enlarge an opening, to realize a satisfactory embedding characteristic of an insulator with which the trench is filled, to make the trench fine, and to secure current capacity which a MOS transistor requires. <P>SOLUTION: Anisotropic oxidation is performed by using a halogen oxidation method using dichloroethylene (DCE). An anisotropic oxide film 26 is formed where film thickness of the shoulder of the trench 22 is thick, and it gradually becomes thin as it goes to a base. The anisotropic oxide film 26 is removed and the shoulder of the trench is preferentially retreated. The corner is sufficiently rounded and the opening is enlarged. Vicinity of the rounded part of the trench shoulder is used as a channel of the MOS transistor. Thus, channel conductance is enlarged and current capacity of the MOS transistor is increased. <P>COPYRIGHT: (C)2007,JPO&INPIT |
