Method of manufacturing a semiconductor device

A method of manufacturing a semiconductor device, comprising the steps of:

• forming an amorphous semiconductor layer on an insulating substrate;
• forming a polycrystalline semiconductor layer by polycrystallization of said amorphous semiconductor layer by solid phase crystallization;
• radiating high energy beam toward said polycrystalline semiconductor layer;
• and
• then providing a heat treatment at a temperature of from 950 to 1100° C. under a temperature condition capable of reducing a surface roughness of said polycrystalline semiconductor layer,
• wherein a step of introducing impurities in the polycrystalline semiconductor layer has not been performed prior to the heat treatment.

A method of manufacturing a semiconductor device, comprising the steps of:

• forming an amorphous semiconductor layer on an insulating substrate;
• forming a polycrystalline semiconductor layer by polycrystallization of said amorphous semiconductor layer by solid phase crystallization;
• and
• then providing a heat treatment at a temperature of from 950 to 1100° C. under a temperature condition capable of reducing a surface roughness of said polycrystalline semiconductor layer,
• wherein a step of introducing impurities in the polycrystalline semiconductor layer has not been performed prior to the heat treatment.