Systems and method for optimization of laser beam spatial intensity profile

Abstract

A thin beam directional crystallization system configured to process a substrate comprises a laser configured to produce laser light, the laser configured to have a high energy mode and a low energy mode. The high energy mode is configured to produce light energy sufficient to completely melt a substrate coated with amorphous silicon film, while the low energy mode is configured to produce light energy that is not sufficient to completely melt a substrate coated with amorphous silicon film. The system further comprises beam shaping optics configured to convert the laser light emitted from the laser into a long thin beam with a short axis and a long axis, a stage configured to support the substrate and film, and a translator coupled with the stage, the translator configured to advance the substrate and film so as to produce a step size in conjunction with the firing of the laser.

1 . A device for processing substrates comprising:
 a laser configured to produce laser light, the laser configured to have a high energy mode and a low energy mode, the high energy mode configured to produce light energy sufficient to completely melt a silicon film, and the low energy mode configured to produce light energy that is not sufficient to completely melt a silicon film;   beam shaping optics coupled to the laser and configured to convert the laser light emitted from the laser into a long thin beam with a short axis and a long axis;   a stage configured to support the substrate and film; and   a translator coupled with the stage, the translator configured to advance the substrate and film so as to produce a step size in conjunction with the firing of the laser, wherein the step size is smaller when the laser is operated in the low energy mode than when the laser is operated in the high energy mode.   
     
     
         2 . The device of  claim 1 , wherein the low energy mode is used to process a display area. 
     
     
         3 . The device of  claim 1 , wherein the high energy mode is used to process a circuit area. 
     
     
         4 . The device of  claim 1 , wherein the beam width in the short axis when the low energy mode is used is approximately 20 μm. 
     
     
         5 . The device of  claim 1 , wherein the step size when the low energy mode is used is approximately 1 μm. 
     
     
         6 . The device of  claim 1 , wherein the step size when in the low energy mode is configured such that approximately 10 shots of the laser occur across the width of an electronic device that can be formed on the substrate. 
     
     
         7 . The device of  claim 1 , wherein the step size in high energy mode is configured to be near a theoretical maximum step size. 
     
     
         8 . The device of  claim 1 , wherein the high energy mode produces approximately 750 mJ/cm 2  at the surface of the substrate. 
     
     
         9 . The device of  claim 1 , wherein the low energy mode produces approximately 250 mJ/cm 2  at the surface of the substrate. 
     
     
         10 . The device of  claim 1 , wherein the step size when in the high energy mode is approximately 5 μm. 
     
     
         11 . The device of  claim 1 , wherein the step size when in the high energy mode is approximately 2.0 μm. 
     
     
         12 . The device of  claim 1 , configured to process a glass panel coated with amorphous silicon. 
     
     
         13 . An apparatus comprising:
 a laser generation module adapted to generate a laser beam;   beam shaping optics adapted to shape the intensity profile of the laser beam in at least the short axis of the beam;   a stage configured to support a target film;   a translator coupled with the stage, the translator adapted to translate the film in a first direction in a number of discrete steps, wherein each of step is governed by a predetermined step size; and   an optimization tool coupled with the laser generation module, the optimization tool adapted to select between a high energy mode and a low energy mode.   
     
     
         14 . The apparatus of  claim 13 , wherein the optimization tool is further adapted to select between a high energy mode and a low energy mode during a single pass of the beam. 
     
     
         15 . The apparatus of  claim 13 , wherein the optimization tool is further coupled to the translator, and wherein the optimization tool is further adapted to select at least one predetermined step size for a given series of steps. 
     
     
         16 . The apparatus of  claim 15 , wherein the optimization tool is further adapted to cause the translator to switch between a plurality of predetermined step sizes during a single pass of the beam. 
     
     
         17 . The apparatus of  claim 13 , wherein the optimization tool is further coupled to the beam shaping optics, and wherein the optimization tool is further adapted to adjust the width of the beam. 
     
     
         18 . The apparatus of  claim 17 , wherein the optimization tool is further adapted to adjust the width of the beam during a single pass of the beam. 
     
     
         19 . A computer-readable medium containing instructions which, when executed by a computer, perform a process comprising:
 selecting a high energy mode or a low energy mode for a laser beam to be generated at a laser generation module;   generating the laser beam at the laser generation module according to the selected mode;   adjusting beam shaping optics to shape of the intensity profile of the laser beam in at least the short axis of the beam;   translating a target film in steps, where each step is governed by a predetermined step size; and   reselecting an energy mode after translating the film a predetermined number of steps.   
     
     
         20 . The computer-readable medium of  claim 19 , wherein the low energy mode is used to process a first area of the film, and wherein the high energy mode is used to process a second area of the film.