| 摘要 |
In an LDMOS, a p<+>-type anode layer (21) is formed adjacent to an n<+>-type drain layer (16). The anode layer (21) makes no contribution to an operation of the LDMOS at a rated voltage and generates holes at the time of ESD. The holes flow into the base layer (14) through the active layer (13). Electrons flow from a source layer (15) into the drain layer (16) through the active layer (13). A parasitic thyristor of the LDMOS thus operates, with the result that a source-to-drain holding voltage can be lowered when a large current flows and the current distribution can be uniformed. <IMAGE> |
