Laser crystallization apparatus and laser crystallization method

Abstract

A laser crystallization apparatus which capable of correcting both shift in imaging position caused by thermal lens effect of the imaging optical system and shift due to flatness of the substrate comprises an crystallization optical system which irradiates laser light to a thin film disposed on the substrate to melt and crystallize an irradiated region of the thin film, the apparatus comprises a measurement light source which is disposed outside a light path of the laser light, and which emits measurement light being illuminated the irradiated region of the thin film, and a substrate height correction system which illuminates the thin film with the measurement light through an imaging optical system in the crystallization optical system, and which detects the reflected measurement light from the thin film.

1 . A laser crystallization method comprising:
 emitting laser light from a laser light source;   irradiating the laser light to a thin film disposed on a substrate through an imaging optical system disposed in a light path of the laser light, and melting and crystallizing the thin film;   emitting measurement light from a light source disposed outside the light path of the laser light;   illuminating the thin film with the measurement light along the light path of the laser light through the imaging optical system; and   detecting the reflected measurement light from the thin film through the imaging optical system.   
   
   
       2 . The laser crystallization method according to  claim 1 , wherein
 the illuminating includes correcting the measurement light in order to image the measurement light in an imaging position of the laser light, and   the detecting includes correcting the measurement light in order to image the reflected measurement light from the thin film in a position conjugated with the imaging position with respect to the measurement light.   
   
   
       3 . The laser crystallization method according to  claim 2 , wherein the detecting includes,
 detecting the reflected measurement light from the thin film, and passed through a pinhole disposed in the conjugated position, and   correcting a position of the thin film to a position where the detected light intensity is maximized by moving the thin film in an optical axis direction of the measurement light.   
   
   
       4 . The laser crystallization method according to  claim 2 , wherein
 the illuminating includes projecting a pattern for measurement onto the thin film, and   the detecting includes,   detecting an image of the pattern for the measurement reflected from the thin film in the position conjugated with the position of the pattern for the measurement, and   correcting the position of the thin film to a position where the detected image of the pattern for the measurement is clearest by moving the thin film in an optical axis direction of the measurement light.   
   
   
       5 . The laser crystallization method according to  claim 1 , wherein the irradiation of the laser light to the thin film is performed after correcting the position of the thin film. 
   
   
       6 . A laser crystallization method comprising:
 emitting laser light from a laser light source;   modulating the laser light into laser light having a predetermined light intensity distribution by a phase modulating element;   irradiating the modulated laser light to a thin film disposed on a substrate to be crystallized through an imaging optical system disposed in a light path of the laser light, and melting and crystallizing the thin film;   emitting measurement light from a light source disposed outside the light path of the laser light;   illuminating the thin film with the measurement light along the light path of the laser light through the imaging optical system; and   detecting the reflected measurement light from the thin film through the imaging optical system.   
   
   
       7 . The laser crystallization method according to  claim 6 , wherein
 the illuminating includes correcting the measurement light in order to image the measurement light in an imaging position of the laser light, and   the detecting includes correcting the measurement light in order to image the reflected measurement light from the thin film in a position conjugated with the imaging position with respect to the measurement light.   
   
   
       8 . The laser crystallization method according to  claim 7 , wherein the detecting includes,
 detecting the measurement light passed through a pinhole disposed in the conjugated position, and reflected from the thin film, and   correcting a position of the thin film to a position where the detected light intensity is maximized by moving the thin film in an optical axis direction of the measurement light.   
   
   
       9 . The laser crystallization method according to  claim 7 , wherein
 the illuminating includes projecting a pattern for measurement onto the thin film, and   the detecting includes,   detecting an image of the pattern for the measurement reflected from the thin film in the position conjugated with the position of the pattern for the measurement, and   correcting the position of the thin film to a position where the detected image of the pattern for the measurement is clearest by moving the thin film in an optical axis direction of the measurement light.   
   
   
       10 . The laser crystallization method according to  claim 6 , wherein the irradiation of the laser light to the thin film is performed after correcting the position of the thin film.