Flat panel display device and method for manufacturing the same using sequental lateral solidifcation and solid phase crystallization
View Patent ↗A flat panel display device includes a substrate including a pixel area having a plurality of pixel parts and a peripheral circuit area disposed adjacent to the pixel area to drive the pixel parts, a circuit TFT disposed in the peripheral circuit area, the circuit TFT including a first semiconductor layer having a first crystal growth in a lateral direction, and a pixel TFT disposed in the pixel area, the pixel TFT including a second semiconductor layer having a second crystal isotropic growth.
1. A method of manufacturing a flat panel display device, the method comprising:
forming a semiconductor layer including amorphous silicon on a substrate having a pixel area and a peripheral circuit area surrounding the pixel area;
first crystallizing the semiconductor layer formed on the peripheral circuit area through a sequential lateral solidification (SLS) process;
second crystallizing the semiconductor layer formed on the peripheral circuit area and the pixel area through a solid phase crystallization (SPC) process;
forming a circuit thin film transistor (TFT) including the semiconductor layer crystallized by the first crystallizing and second crystallizing, wherein the circuit TFT is formed in the peripheral circuit area;
forming a pixel TFT including the semiconductor layer crystallized by the second crystallizing, wherein the pixel TFT is formed in the pixel area; and
forming a first electrode connected to the pixel TFT,
wherein first crystallizing and second crystallizing are performed successively with each other.
2. The method of claim 1 , wherein the second crystallizing is performed after the first crystallizing.
3. The method of claim 1 , wherein the first crystallizing is performed after the second crystallizing.
4. The method of claim 1 , further comprising: forming an organic light emitting layer on the first electrode; and forming a second electrode on the organic light emitting layer corresponding to the pixel area.
5. The method of claim 4 , wherein the pixel area comprises a plurality of pixel parts and the first electrode corresponding to each of the pixel parts.
6. The method of claim 1 , wherein the first crystallizing using the SLS process comprises:
irradiating a laser beam onto a slit mask corresponding to a first portion of the peripheral circuit area to crystallize a portion of the semiconductor layer;
shifting the slit mask at a predetermined distance in the peripheral circuit area; and
irradiating a laser beam onto the shifted slit mask to crystallize a second portion of the peripheral circuit area.
7. The method of claim 1 , wherein the second crystallizing using the SPC process is performed at a heat-treatment temperature in a range of from about 600° C. to about 1000° C.
8. The method of claim 1 , further comprising: forming a color filter between the pixel TFT and the first electrode.
9. The method of claim 1 , further comprising: coupling a countering substrate with the substrate; and injecting a liquid crystal layer between the substrate and the countering substrate.
10. The method of claim 9 , further comprising: forming a common electrode on a surface of the countering substrate that faces the substrate.