Patent ID: 9412832
Filing Date: 2016-08-09
CPC Classification: H01L

Claim Text:
1. A semiconductor device manufacturing method, the method comprising: a step of grinding the back surface of a first conductivity type semiconductor substrate formed by being doped with antimony, thereby reducing the thickness of the semiconductor substrate; a step of ion implanting a first conductivity type impurity into the ground back surface of the semiconductor substrate; a step of activating the first conductivity type impurity implanted into the semiconductor substrate by carrying out a heat treatment for 30 minutes or more at a temperature of 340° C. or more, 500° C. or less, thereby forming a first conductivity type contact layer in a surface layer of the back surface of the semiconductor substrate; and a step of forming a first electrode in contact with the contact layer, wherein the first conductivity type impurity is phosphorus, wherein lattice defects remain in the step of activating the first conductivity type impurity, and wherein in the step of activating the first conductivity type impurity, both a region of higher concentration than that of the semiconductor substrate, and a region of lower concentration region than that of the semiconductor substrate are formed.