Power semiconductor device having resurf layer

摘要

A semiconductor device includes a drain electrode (16), a drain layer (10), first and second drift layers (11,19), a RESURF layer (18), a base layer (12), a source layer (13), a source electrode (17), and a gate electrode (15). The first drift layer (11) is formed on the drain layer (10). The second drift layer (19) and RESURF layers (18) are formed on the first drift layer (11) and periodically arranged in a direction perpendicular to the direction of depth. The RESURF layer (18) forms a depletion layer in the second drift layer (19) by a p-n junction including the second drift layer (19) and RESURF layer (18). The impurity concentration in the first drift layer (11) is different from that in the second drift layer (19). The drain electrode (16) is electrically connected to the drain layer (10).