Semiconductor device and semiconductor device manufacturing method

摘要

In aspects of the invention, an n-type epitaxial layer that forms an n− type drift layer is formed on the upper surface of an n-type semiconductor substrate formed by being doped with a high concentration of antimony. A p-type anode layer is formed on a surface of the n− type drift layer. An n-type contact layer is formed with an impurity concentration in the same region as the impurity concentration of the n-type cathode layer, or higher than the impurity concentration of the n-type cathode layer, on the lower surface of the n-type cathode layer. A cathode electrode is formed so as to be in contact with the n-type contact layer. The n-type contact layer is doped with phosphorus and, without allowing complete recrystallization using a low temperature heat treatment of 500° C. or less, lattice defects are allowed to remain.

主权项

1. A semiconductor device comprising:
a first conductivity type semiconductor substrate, wherein a dopant of the semiconductor substrate is antimony; a first conductivity type contact layer, provided on the back surface of the semiconductor substrate, with a concentration higher than that of the semiconductor substrate; and a first electrode in contact with the contact layer, wherein the contact layer is doped with phosphorus and includes lattice defects, the maximum carrier concentration of the contact layer is greater than 1.0×1018/cm3 and less than 5.0×1019/cm3, and the diffusion depth of the contact layer from the interface with the first electrode into the semiconductor substrate is 0.5 μm or less; the semiconductor device further comprising: a first conductivity type drift layer, provided on the front surface of the semiconductor substrate, with a concentration lower than that of the semiconductor substrate, wherein the total of the thickness of the drift layer and the thickness of the semiconductor substrate is less than 300 μm; a second conductivity type base region provided in a surface layer on the side of the drift layer opposite to that of the semiconductor substrate; and a second electrode electrically connected to the base region.