Trenched semiconductor devices and their manufacture

摘要

In semiconductor devices which include an insulated trench electrode ( 11 ) in a trench ( 20 ), for example, trench-gate field effect power transistors and trenched Schottky diodes, a cavity ( 23 ) is provided between the bottom ( 25 ) of the trench electrode ( 11 ) and the bottom ( 27 ) of the trench ( 20 ) to reduce the dielectric coupling between the trench electrode ( 11 ) and the body portion at the bottom ( 27 ) of the trench in a compact manner. In power transistors, the reduction in dielectric coupling reduces switching power losses, and in Schottky diodes, it enables the trench width to be reduced.