Semiconductor device including crystal defect region and method for manufacturing the same

A method for manufacturing a semiconductor device, comprising:

• forming an element structure including at least an active side second conductivity type layer to form a pn junction with a first conductivity type portion of a first conductivity type semiconductor layer including an active region and an inactive region, in the active region of the first conductivity type semiconductor layer;
• forming an inactive side second conductivity type layer to form a pn junction with the first conductivity type portion of the first conductivity type semiconductor layer, in the inactive region;
• forming a level difference on the rear surface of the first conductivity type semiconductor layer between the active region and the inactive region such that a level of the active region is lower than a level of the inactive region;
• irradiating charged particles over the entire rear surface of the first conductivity type semiconductor layer after forming the level difference to form a crystal defect region which is formed in both of the active region and the inactive region, the crystal defect region in the active region being at a first depth within the first conductivity type portion and the crystal defect region in the inactive region being at a second depth within the first conductivity type portion, and the second depth being different from the first depth;
• forming a first electrode to be electrically connected to the active side second conductivity type layer in a front surface of the first conductivity type semiconductor layer;
• and
• forming a second electrode to be electrically connected to the first conductivity type portion of the first conductivity type semiconductor layer in the rear surface of the first conductivity type semiconductor layer.