Patent ID: 7842565

Claim:
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 first convex lens and a first concave lens are combined; a second lens system in which a second convex lens and a second 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, 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.