LTPS TFT substrate structure and method of forming the same

摘要

A method of forming an LTPS TFT substrate includes: Step 1: providing a substrate (1) and depositing a buffer layer (2); Step 2: depositing an a-Si layer (3); Step 3: depositing and patterning a silicon oxide layer (4); Step 4: taking the silicon oxide layer (4) as a photomask and annealing the a-Si layer (3) with excimer laser, so that the a-Si layer crystalizes and turns into a poly-Si layer; Step 5: forming a first poly-Si region (31) and a second poly-Si region (32); Step 6: defining a heavily N-doped area and a lightly N-doped area on the first and second poly-Si regions (31) and (32), and forming an LDD area; Step 7: depositing and patterning a gate insulating layer (5); Step 8: forming a first gate (61) and a second gate (62); Step 9: forming via holes (70); and Step 10: forming a first source/drain (81) and a second source/drain (82).

主权项

1. A LTPS TFT substrate, comprising:
a substrate; a buffer layer on the substrate; a first poly-Si region and a second poly-Si region arrayed on the buffer layer with a space between the two regions; a first source/drain and a second source/drain disposed above the first poly-Si region and the second poly-Si region; a gate insulating layer installed on the buffer layer, the first poly-Si region and second poly-Si region; a first gate and a second gate installed on the gate insulating layer corresponding to the first poly-Si region and second poly-Si region; an interlayer dielectric layer installed on the gate insulating layer, the first gate and the second gate; wherein both sides of the first poly-Si region and the second poly-Si region are next to a heavily N-doped area, which connects to the first source/drain and the second source/drain through the via hole; a display area and a drive area, with the first poly-Si region in the display area of the LTPS TFT substrate, and the second poly-Si region in the drive area of the LTPS TFT substrate; grains of the first poly-Si region are smaller than those of the second poly-Si region, while a uniformity of the grains of the first poly-Si region is larger than that of the second poly-Si region.