| 摘要 |
PROBLEM TO BE SOLVED: To inhibit an unintended increase in threshold voltage associated with a narrow channel of a MISFET to promote refinement and high breakdown voltage of the MISFET.SOLUTION: A semiconductor device comprises a p-type channel stopper region 18 for inversion prevention which is formed on a lower part of an element isolation trench 11 and formed in a manner such that an end project toward a channel region on a lower part of a gate oxide film 15 but which does not reach the channel region and off-set with respect to an end (an end of the element isolation trench 11) of the channel region. With this composition, diffusion of an impurity of the p-type channel stopper region 18 in a lateral direction (channel region direction) is inhibited and a decrease in carrier concentration at the end of the channel region is inhibited. Accordingly, a local increase in threshold voltage is suppressed. |
