Method for selective laser crystallization and display panel fabricated by using the same

Abstract

A display panel comprises a substrate having a displaying region (such as active organic light emitting region) and a circuit driving region; and a polysilicon layer formed on the substrate and having a first polysilicon portion and a second polysilicon portion respectively corresponding to the displaying region and circuit driving region, wherein the grain size of the second polysilicon portion crystallized by continuous wave (CW) laser annealing method is larger than that of the first polysilicon portion crystallized by excimer laser annealing (ELA) method.

1 . A method for fabricating a display panel, comprising steps of: 
 providing a substrate having a displaying region and a circuit driving region; and    depositing an amorphous silicon layer on the substrate, and the amorphous silicon layer having a first amorphous silicon portion and a second amorphous silicon portion respectively associated to the displaying region and the circuit driving region;    crystallizing the second amorphous silicon portion by a continuous wave laser beam to form a second polysilicon portion; and    crystallizing the first amorphous silicon portion to form a first polysilicon portion.    
   
   
       2 . The method according to  claim 1  further comprising a step of: 
 forming an alignment mark on the amorphous silicon layer by photolithography.    
   
   
       3 . The method according to  claim 1 , wherein after the first and the second polysilicon portions are formed, the method further comprises steps of: 
 forming a first transistor and a second transistor at the circuit driving region of the substrate; and    forming an electroluminescence component coupled to the second transistor.    
   
   
       4 . The method according to  claim 3 , wherein the electroluminescence device is an organic light emitting diode.  
   
   
       5 . The method according to  claim 1 , wherein at least one of the first polysiicon portion and the second polysilicon portion is low-temperature polysilicon (LTPS).  
   
   
       6 . The method according to  claim 1 , wherein crystallizing the first amorphous silicon portion to form the first polysilicon portion comprises crystallizing the first amorphous silicon portion by a continuous wave laser beam to form the first polysilicon portion.  
   
   
       7 . The method according to  claim 1 , wherein crystallizing the first amorphous silicon portion to form the first polysilicon portion comprises crystallizing the first amorphous silicon portion by an excimer laser to form the first polysilicon portion.  
   
   
       8 . The method according to  claim 1 , wherein crystallizing the first amorphous silicon portion to form the first polysilicon portion comprises crystallizing the first amorphous silicon portion by a laser beam pulse to form the first polysilicon portion.  
   
   
       9 . A display panel manufactured by the method of  claim 1 .  
   
   
       10 . A display panel, comprising: 
 a substrate having a displaying region and a circuit driving region; and    a polysilicon layer, formed on the substrate, having a first polysilicon portion and a second polysilicon portion associated with the displaying region and the circuit driving region, respectively;    wherein a plurality of grains of the second polysilicon portion are stripe-shaped.    
   
   
       11 . A display panel according to  claim 10 , wherein the size of at least one of the grains of the second polysilicon portion is greater than about  1  micrometer.  
   
   
       12 . A display panel according to  claim 10 , wherein the size of at least one of the grains of the second polysilicon portion is greater than about 10 micrometer.  
   
   
       13 . A display panel according to  claim 10 , wherein a grain boundary of the second polysilicon portion is sparser than a grain boundary of the first polysilicon portion.  
   
   
       14 . A display panel according to  claim 10 , wherein at least one of the first polysiicon portion and the second polysilicon portion is low-temperature polysilicon (LTPS).  
   
   
       15 . A display panel according to  claim 10 , wherein the substrate is an active matrix organic light emitting diode substrate (AM-OLED substrate).