Patent ID: 6596613
Filing Date: 2003-07-22
Classification: B23K,H01L

Abstract:
A laser annealing method comprising:emitting pulse laser beams at a rate of N times per second; shaping the pulse laser beams into beams elongated in one direction at an irradiation surface through an optical systems, beams having a multi-step energy distribution of width L (m) perpendicular to the direction, and the beams having substantially a constant energy distribution along the direction; applying the beams to an arbitrarily selected portion of a semiconductor film comprising silicon having a thickness between 150 and 1000 Ã¥; and scanning the semiconductor film with the beams 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&lE;LN/V&lE;100, and wherein the width L (m) is defined as beams in a region having 5% or more of an energy density with respect to a maximum energy density of the beams on the irradiation surface.