Semiconductor device and method of manufacturing the same

摘要

An isolation insulating film ( 5 ) of partial-trench type is selectively formed in an upper surface of a silicon layer ( 4 ). A power supply line ( 21 ) is formed above the isolation insulating film ( 5 ). Below the power supply line ( 21 ), a complete isolation portion ( 23 ) reaching an upper surface of an insulating film ( 3 ) is formed in the isolation insulating film ( 5 ). In other words, a semiconductor device comprises a complete-isolation insulating film which is so formed as to extend from the upper surface of the silicon layer ( 4 ) and reach the upper surface of insulating film ( 3 ) below the power supply line ( 21 ). With this structure, it is possible to obtain the semiconductor device capable of suppressing variation in potential of a body region caused by variation in potential of the power supply line.