Patent ID: 7517774

Claim:
A method of manufacturing a semiconductor device comprising: forming a semiconductor film over a substrate; emitting a pulse laser light at a rate of N pulses per second; shaping the pulse laser light into a beam having a cross section perpendicular to a propagation direction of the beam, said cross section having a width and a length, wherein the length is longer than the width, wherein the beam has a width L (m) perpendicular to the length direction, and the beam having substantially a constant energy distribution along a lengthwise direction; applying the beam to a portion of the semiconductor film; and scanning the semiconductor film with the beam perpendicular to the lengthwise direction of the cross section at a speed V (m/s), wherein the scanning step is conducted in air, wherein the number of beams applied to said portion in one scan satisfies a relationship 3≦LN/V≦100, and wherein the width L (m) is defined as a beam in a region having 5% or more of an energy density with respect to a maximum energy density of the beam on the irradiation surface.