Patent ID: 6947452

Claim:
A method of manufacturing a semiconductor device comprising: forming a semiconductor film having a thickness between 150 and 1000 Å over a substrate; emitting a pulse laser light at a rate of N pulses per second; shaping the pulse laser light into a beam elongated in one direction at an irradiation surface through an optical system, the beam having a normal-distribution type energy profile of width L (m) perpendicular to the direction, where L is larger than zero and the beam having substantially a constant energy distribution along the direction; applying the beam to an arbitrarily selected portion of the semiconductor film; and scanning the semiconductor film with the beam perpendicular to the direction at a speed V (m/s), wherein the number of beams applied to the arbitrarily selected 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.