Patent ID: 7955911

Claim:
A method for manufacturing a TFT-LCD pixel unit, comprising: a) step 1 using a first gray tone mask, comprising: i) sequentially depositing a gate metal layer, a first gate insulating layer, an active layer, and a doped layer on a substrate; ii) forming a first photoresist pattern on the substrate with the first gray tone mask, including a first photoresist-free region, a first photoresist partially retained region, and a first photoresist fully retained region; iii) etching the first photoresist-free region to expose the substrate and to form a gate line and a gate electrode from the gate metal layer; iv) performing an ashing process on the first photoresist pattern to remove photoresist in the first photoresist partially retained region entirely and reduce a thickness of photoresist in the first photoresist fully retained region, such that a part of the doped layer on the gate line are exposed; v) etching the exposed doped layer and the active layer to obtain an intercepting trench on the gate line; b) step 2 using a second mask, comprising: i) depositing a source and drain metal layer on the substrate; and ii) patterning the source and drain metal layer with the second mask to obtain a source and drain metal layer pattern, and c) step 3 using a third gray tone mask, comprising: i) depositing a pixel electrode layer on the substrate; ii) forming a third photoresist pattern with the third mask on the substrate, including a third photoresist-free region and a third photoresist retained region; and iii) etching the third photoresist-free region to form a TFT channel.