SEMICONDUCTOR DEVICE

PROBLEM TO BE SOLVED: To provide a semiconductor device which has a structure for preventing malfunction of a semiconductor element due to a parasitic current flowing between the semiconductor elements formed on the same substrate. SOLUTION: The device includes: a bipolar transistor 50 which is a small signal element provided with an n-type collector leading-out layer 53 electrically connected to a p-type semiconductor substrate 1; a DMOS transistor 60 which is a power transistor element provided with an n-type diffusion layer 67 electrically connected to the p-type semiconductor substrate 1; an n-type dummy N-island 10 which is electrically connected to the p-type semiconductor substrate 1 and further connected to a dummy electrode 13; a p-type field part 20 which is electrically connected to the p-type semiconductor substrate 1 and further connected to a field electrode 23; and a wiring 30 which connects the dummy electrode 13 and the field electrode 23, and is connected to a bonding pad 70. COPYRIGHT: (C)2010,JPO&INPIT