Method of fabricating pixel structure and pixel structure thereof

1. A method of forming a pixel structure, comprising:

providing a substrate;

forming a patterned semiconductor layer on the substrate;

forming an insulation layer on the patterned semiconductor layer;

forming a patterned metal layer on the insulation layer, wherein the patterned metal layer partially overlap the patterned semiconductor layer in a perpendicular projection direction;

forming a first inter-layer dielectric (ILD) layer covering the patterned metal layer after forming the patterned metal layer;

performing a low temperature annealing process after forming the first ILD layer;

performing a hydrogen plasma treatment process after the low temperature annealing process;

forming a second ILD layer covering the first ILD layer after the hydrogen plasma treatment process;

forming a third ILD layer covering the second ILD layer;

forming a first contact window and a second contact window in the third ILD layer, the second ILD layer, the first ILD layer and the insulation layer to partially expose the patterned semiconductor layer, respectively;

forming a source electrode and a drain electrode on the third ILD layer, wherein the source electrode is electrically connected to the patterned semiconductor layer via the first contact window, and the drain electrode is electrically connected to the patterned semiconductor layer via the second contact window;

forming a passivation layer on the source electrode and the drain electrode, and forming a third contact window in the passivation layer to partially expose the drain electrode; and

forming a pixel electrode on the passivation layer, the pixel electrode being electrically connected to the drain electrode via the third contact window.

2. The method of forming the pixel structure according to claim 1 , wherein a thickness of the first ILD layer is substantially in a range between 20 nanometers (nm) and 40 nm.

3. The method of forming the pixel structure according to claim 1 , wherein a sum of the thickness of the first ILD layer and a thickness of the second ILD layer is substantially in a range between 200 nm and 400 nm.

4. The method of forming the pixel structure according to claim 1 , wherein a thickness of the third ILD layer is substantially in a range between 200 nm and 400 nm.

5. The method of forming the pixel structure according to claim 1 , wherein the first ILD layer and the second ILD layer comprise silicon oxide (SiOx).

6. The method of forming the pixel structure according to claim 1 , wherein the third ILD layer comprises silicon nitride (SiNx).

7. The method of forming the pixel structure according to claim 1 , wherein a temperature of the low temperature annealing process is substantially equal to or lower than 400° C. .

8. The method of forming the pixel structure according to claim 1 , further comprising performing a doping process to form a doping source and a doping drain in the patterned semiconductor layer that are uncovered by the patterned metal layer in the perpendicular projection direction.

9. The method of forming the pixel structure according to claim 8 , further comprising:

removing a part of the patterned metal layer to form a gate electrode; and

forming a light doping source between the doping source and the channel layer and forming a light doping drain between the doping drain and the channel layer, thereby a channel layer is formed in a portion of the patterned semiconductor layer overlapping the gate electrode in the perpendicular projection direction.