A method for manufacturing a semiconductor device with a substrate having a device
layer and a backside electrode is disclosed. Here, a surface roughness of the substrate
is defined as a ratio between a substantial area and a projected area. The method
includes polishing and wet-etching a backside surface of the substrate mechanically
with using predetermined abrasive grains so that a surface roughness of the backside
surface of the substrate becomes to be equal to or larger than 1.04, and forming
the backside electrode on the backside surface of the substrate after polishing
and wet-etching the backside surface of the substrate.
