SEMICONDUCTOR DEVICE

摘要

PROBLEM TO BE SOLVED: To improve the reliability of a semiconductor device in which a trench for a contact is formed.SOLUTION: A semiconductor device 1 comprises a first metal portion 14a in contact with a bottom surface of a trench 30; a second metal portion 14b in contact with a side surface of the trench 30; and a third metal portion 14c surrounded by the first metal portion 14a and the second metal portion 14b. The first metal portion 14a is in ohmic contact with a p-type base region 26. The second metal portion 14b is in ohmic contact with an n-type source region 28. The coefficient of thermal expansion of the material of the third metal portion 14c is equal to or less than that of the material of the second metal portion 14b.