Laser processing method

Abstract

Method of processing, e.g., laser annealing, objects such as semiconductor devices with pulsed lasers with high production yield and high reproducibility so as to obtain good characteristics stably. The pulse width of the irradiated pulse beam is set to more than 30 nsec to stabilize the processing. To achieve a pulse width exceeding 30 nsec, plural lasers are connected in series or in parallel and excited successively.

1. A laser processing method comprising the steps of:
 generating a laser pulse from a laser, said laser pulse having a pulse width duration w; and    amplifying said laser pulse by the step of activating a laser amplifier at a time t after said generating step, wherein said time t is between about 0.5 times said pulse, width duration w and 5.0 times said pulse width duration w; and    processing an object with said laser pulse emitted from said laser amplifier.    
     
     
       2. The method of  claim 1  wherein said processing stan further comprises the step of irradiating said object with said laser pulse. 
     
     
       3. The method of  claim 1  wherein said object is a semiconductor which is substantially amorphous. 
     
     
       4. The method of  claim 1  wherein said object is a substantially amorphous silicon semiconductor containing at least 1 volume % of hydrogen. 
     
     
       5. The method of  claim 1  further comprising the step of activating said laser by a pulse generated by a trigger pulse-generation means connected to said laser and said laser amplifier. 
     
     
       6. The method of  claim 1  further comprising the step of activating said laser amplifier by a pulse generated by a trigger pulse generation means connected to said laser and said laser amplifier. 
     
     
       7. A laser processing method comprising the steps of:
 generating a laser pulse from a laser, said laser pulse having a pulse width duration w;    amplifying said laser pulse by activating a laser amplifier at a time t after said generating step, wherein said time t is between about 0.5 times said pulse width duration w and 5.0 times said pulse width duration w; and    processing an amorphous silicon film containing hydrogen at a concentration of 10 to 30% with said laser pulse.    
     
     
       8. The method of  claim 7  wherein the irradiated laser pulse has one peak of a pulse height thereof which is the same as that of the laser pulse as generated from said laser device, and has another peak of a pulse height following said one peak wherein the pulse height of said one peak is from about 0.25 to 0.50 times the pulse height of said another peak. 
     
     
       9. The method of  claim 8  wherein said another peak is formed by said amplifying step. 
     
     
       10. The method of  claim 7  further comprising the step of activating said laser by a pulse generated by a trigger pulse generation means connected to said laser and said laser amplifier. 
     
     
       11. The method of  claim 7  further comprising the step of activating said laser amplifier by a pulse generated by said trigger pulse generation means connected to said laser and said laser amplifier. 
     
     
       12. The method of  claim 7  further comprising the step of improving crystallinity of said silicon film by irradiating said silicon film with said laser pulse. 
     
     
       13. A laser processing method comprising the steps of:
 generating a laser pulse from a laser, said laser pulse having a pulse width duration w;    amplifying said laser pulse by activating a laser amplifier at a time t after said generating step, wherein said time t is between about 0.5 times said pulse width duration w and 5.0 times said pulse width duration w; and    processing a silicon oxide film containing carbon at a concentration of 0.1 to 1% with said laser pulse.    
     
     
       14. The method of  claim 13  further comprising the step of forming said silicon oxide film by chemical vapor deposition using tetraethoxysilane. 
     
     
       15. The method of  claim 13  wherein said processing step comprises the step of desorbing the carbon in said silicon oxide film. 
     
     
       16. The method of  claim 13  further comprising the step of activating said laser by a pulse generated by said trigger pulse generation means connected to said laser and said laser amplifier. 
     
     
       17. The method of  claim 13  further comprising the step of activating said laser amplifier by a pulse generated by said trigger pulse generation means connected to said laser and said laser amplifier. 
     
     
       18. A manufacturing method of a semiconductor device comprising the steps of:
   forming a semiconductor film over a substrate;        generating a laser pulse from a laser, said laser pulse having a pulse width duration w;        amplifying said laser pulse at a time t after said generating step, wherein said time t is between about  0 . 5  times said pulse width duration w and  5 . 0  times said pulse width duration w;        irradiating said semiconductor film with said amplified laser pulse to crystallize said semiconductor film; and        manufacturing a thin film transistor by using said semiconductor film.      
     
     
       19. The method according to  claim 18  wherein said semiconductor film formed over said substrate comprises amorphous silicon.  
     
     
       20. The method according to  claim 18  wherein said laser is an excimer laser.  
     
     
       21. The method according to  claim 20  wherein said excimer laser is selected from Ar 2    laser, Kr   2    laser, Xe   2    laser, ArF laser, KrCl laser, KrF laser, XeCl laser and XeF laser.    
     
     
       22. A manufacturing method of a semiconductor device comprising the steps of:
   forming a semiconductor film over a substrate;        generating a laser pulse from a laser, said laser pulse having a pulse width duration w;        amplifying said laser pulse at a time t after said generating step, wherein said time t is not longer than  5 . 0  times said pulse width duration;        irradiating said semiconductor film with said amplified laser pulse to crystallize said semiconductor film; and        manufacturing a thin film transistor by using said semiconductor film,        wherein said amplified laser pulse has a pulse width longer than  100  nsec.      
     
     
       23. The method according to  claim 22  wherein said semiconductor film formed over said substrate comprises amorphous silicon.  
     
     
       24. The method according to  claim 22  wherein said laser is an excimer laser.  
     
     
       25. The method according to  claim 24  wherein said excimer laser is selected from Ar 2    laser, Kr   2    laser, Xe   2    laser, ArF laser, KrCl laser, KrF laser, XeCl laser and XeF laser.    
     
     
       26. A manufacturing method of a semiconductor device comprising the steps of:
   forming a semiconductor film over a substrate;        generating a laser pulse from a laser, said laser pulse having a pulse width duration w;        amplifying said laser pulse at a time t after said generating step, wherein said time t is not longer than  5 . 0  times said pulse width duration;        irradiating said semiconductor film with said amplified laser pulse to crystallize said semiconductor film; and        manufacturing a thin film transistor by using said semiconductor film,        wherein said amplified laser pulse comprises at least first and second pulses occurring continuously, said second pulse having a higher pulse height than said first pulse.      
     
     
       27. The method according to  claim 26  wherein said semiconductor film formed over said substrate comprises amorphous silicon.  
     
     
       28. The method according to  claim 26  wherein said laser is an excimer laser.  
     
     
       29. The method according to  claim 28  wherein said excimer laser is selected from Ar 2    laser, Kr   2    laser, Xe   2    laser, ArF laser, KrCl laser, KrF laser, XeCl laser and XeF laser.    
     
     
       30. A manufacturing method of a semiconductor device comprising the steps of:
   forming a semiconductor film over a substrate;        generating a laser pulse from a laser, said laser pulse having a pulse width duration w;        amplifying said laser pulse at a time t after said generating step, wherein said time t is not longer than  5 . 0  times said pulse width duration;        irradiating said semiconductor film with said amplified laser pulse to crystallize said semiconductor film; and        manufacturing a thin film transistor by using said semiconductor film,        wherein said amplified laser pulse comprises at least first and second pulses occurring continuously, said second pulse having a higher pulse height than said first pulse,        wherein said laser pulse has a pulse width longer than  100  nsec.      
     
     
       31. The method according to  claim 30  wherein said semiconductor film formed over said substrate comprises amorphous silicon.  
     
     
       32. The method according to  claim 32  wherein said laser is an excimer laser.  
     
     
       33. The method according to  claim 32  wherein said excimer laser is selected from Ar 2    laser, Kr   2    laser, Xe   2    laser, ArF laser, KrCl laser, KrF laser, XeCl laser and XeF laser.