Beam homogenizer and laser irradiation apparatus

A method of manufacturing a semiconductor device comprising:

• forming a semiconductor film over a substrate;
• crystallizing the semiconductor film by irradiating a laser beam homogenized by a beam homogenizer;
• forming a semiconductor layer by patterning the semiconductor film;
• forming a gate electrode over the semiconductor layer with a gate insulating film interposed therebetween;
• and
• doping an impurity element to the semiconductor layer selectively to form a source region and a drain region in the semiconductor layer,
• wherein the beam homogenizer comprises:
• a first lens system in which a convex lens and a concave lens are combined;
• a second lens system;
• and
• a condensing lens;
• wherein a focus of the first lens system is positioned between the first lens system and the second lens system,
• wherein a second principal point of the first lens system is positioned on a beam incidence side of the first lens system, and
• wherein the first lens system and the second lens system and the condensing lens are arranged along a same optical path in series.

A method of manufacturing a semiconductor device comprising:

• forming a semiconductor film over, a substrate;
• crystallizing the semiconductor film by irradiating a laser beam homogenized by a beam homogenizer;
• forming a semiconductor layer by patterning the semiconductor film;
• forming a gate electrode over the semiconductor layer with a gate insulating film interposed therebetween;
• and
• doping an impurity element to the semiconductor layer selectively to form a source region and a drain region in the semiconductor layer;
• wherein the beam homogenizer comprises:
• a first lens system;
• a second lens system in which a convex lens and a concave lens are combined;
• and
• a condensing lens;
• wherein a focus of the first lens system is positioned between the first lens system and the second lens system,
• wherein a first principal point of the second lens system is positioned on a beam emission side of the second lens system, and
• wherein the first lens system and the second lens system and the condensing lens are arranged along a same optical path in series.