Method for selective laser crystallization and display panel fabricated by using the same
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:
providing a substrate having a displaying region and a circuit driving region;
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 only the second amorphous silicon portion by a continuous wave laser beam to form a second polysilicon portion; and
crystallizing the first amorphous silicon portion excluding the second amorphous silicon portion to form a first polysilicon portion, wherein the crystallizing methods applied to the first amorphous silicon portion and the second amorphous silicon portion are different.
2. The method according to claim 1 , further comprising:
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:
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 3 , wherein at least one of the first polysilicon portion and the second polysilicon portion is comprised of low-temperature polysilicon (LTPS).
6. The method according to claim 1 , wherein at least one of the first polysilicon portion and the second polysilicon portion is comprised of low-temperature polysilicon (LTPS).
7. The method according to claim 1 , wherein the step of 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 the step of 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. The method according to claim 1 , wherein the step of crystallizing the first amorphous silicon portion to form the first polysilicon portion comprises crystallizing the first amorphous silicon portion by a continuous grain silicon (CGS) method, a sequential lateral solidification (SLS) method, excimer laser annealing (ELA) method or a metal induced lateral crystallization (MILC) method to form the first polysilicon portion.