Patent ID: 8987027
Filing Date: 2015-03-24
Classification: H01L

Abstract:
1. A method of fabricating thin-film transistors (TFTs) for an LCD having an array of pixels with an active area of the pixels and with an area surrounding the active area of the pixels, the method comprising: depositing a first photoresist layer over a portion of a TFT stack, the TFT stack comprising a conductive gate layer, and a semiconductor layer; doping the exposed semiconductor layer with a first doping dose; etching a portion of the conductive gate layer to expose a portion of the semiconductor layer; doping the exposed portion of the semiconductor layer with a second doping dose, wherein the exposed portion of the semiconductor layer receiving the second doping dose is in the area surrounding the active area of the pixels, and the active area of the pixels does not receive said second doping dose; removing the first photoresist layer; depositing a second photoresist layer over a first portion of the doped semiconductor layer in the active area of the pixels to expose a second portion of the doped semiconductor layer in the area surrounding the active area; and doping the second portion of the doped semiconductor layer with a third doping dose, the third dose being higher in dopant concentration than the second dose and the first dose; wherein the area surrounding the active area of the pixels has a higher dopant concentration that the active area of the pixels.