Semiconductor device with connection structure - has surface section of conductive region in substrate surface with surface roughness greater than that of substrate

摘要

A conductive region (3) is formed in the main surface of a semiconductor substrate (1) which has a first surface roughness. A surface section of the conductive region has a second surface roughness which is greater than the first, substrate surface roughness. An insulating layer (15) formed on the conductive region has an opening (15a) which reaches the surface section. A conductive layer is formed on the side wall of the opening. A connection layer is formed in contact with the surface section. The connection layer is of a different material than the conductive layer. ADVANTAGE - Connection structure has reduced contact resistance.