A field effect transistor and a production method therefor.

摘要

In a field effect transistor and a production method thereof, a p-type layer (19) is provided at a region at source side so as not to accumulate positive holes which have flown to the source side to a high concentration. By surrounding the source side region by the p-type layer (19) and making positive holes stray to the ground through a high concentration p-type layer (18), it can be avoided that the positive holes generated at the drain side region and accumulated to the source side region weaken the electric field in a substrate (4) at the source side as well as the high concentration positive hole region (16) extends out to the drain side thereby to strengthen the electric field at the drain end region at the drain side as in the prior art, whereby the improvement in the drain breakdown voltage is enabled.