Process for producing semiconductor device and semiconductor device

A process for producing a semiconductor device comprising the steps of:

• forming a semiconductor layer containing a dopant;
• forming a concave and convex structure on the semiconductor layer by partially removing the semiconductor layer;
• and
• forming a conductivity distribution reflecting the concave and convex structure in the semiconductor layer by performing heat treatment on the semiconductor layer in which the concave and convex structure has been formed at a temperature at which a material forming the semiconductor layer causes mass transport and filling up at least a part of a hole of a concave portion of the concave and convex structure with the material forming the semiconductor layer,
• wherein a first region corresponding to the concave portion of the concave and convex structure filled up with the material forming the semiconductor layer and a second region corresponding to the convex portion of the concave and convex structure have a same element as dopant, and
• wherein a concentration of the same element in the first region is lower than that in the second region.