Patent ID: 7255899

Claim:
A heat treatment method, which carries out a heat treatment on a substrate by applying light onto said substrate, the method comprising the steps of: a) loading a glass substrate having a silicon film formed on a surface thereof into a heat treatment chamber, said glass substrate having a thickness of 0.5 mm to 1.1 mm; b) preliminarily heating said glass substrate loaded into said heat treatment chamber to a temperature of not less than 200° C. to not more than 400° C. with thermal energy from a heating plate; c) after having heated said glass substrate in said heat treatment chamber to a predetermined pre-heating temperature, applying flash light of a xenon flash lamp onto said glass substrate for an applying period of time from not less than 0.1 msec to not more than 10 msec, so that said silicon film formed on said surface of said pre-heated glass substrate is heated to a treatment temperature of not less than 500° C. to not more than 600° C., said xenon flash lamp having an irradiation intensity in a range from not less than 10 J/cm 2 to not more than 30 J/cm 2 when said xenon flash lamp is lighted; d) stopping the preliminarily heating process of said glass substrate by the use of said heating plate with said heat treatment chamber opened to the atmosphere; and e) carrying said glass substrate out of said heat treatment chamber.