Patent ID: 9012275
Filing Date: 2015-04-21
Classification: H01L

Abstract:
1. A method of forming a thin film transistor, comprising: providing a substrate; forming a gate electrode on the substrate; forming a gate insulating layer on the gate electrode and the substrate; forming a first protective pattern, a second protective pattern, a source electrode and a drain electrode on the gate insulating layer, wherein the source electrode is formed on the first protective pattern, the drain electrode is formed on the second protective pattern, the first protective pattern and the second protective pattern are made of a metal oxide and disposed on the gate insulating layer above the gate electrode and in physical contact with a top surface of the gate insulating layer, the first protective pattern has a first outer fringe and a first inner fringe and the second protective pattern has a second outer fringe and a second inner fringe with the first inner fringe of the first protective pattern and the second inner fringe of the second protective pattern facing each other, the source electrode covers a side of the first outer fringe of the first protective pattern and the drain electrode covers a side of the second outer fringe of the second protective pattern; forming a semiconductor channel layer on a top surface of the source electrode and a top surface of the drain electrode, and on the gate insulating layer between the source electrode and the drain electrode; forming a passivation layer on the semiconductor channel layer, the source electrode and the drain electrode; wherein in an extending direction from the source electrode to the drain electrode a length of the first protective pattern is shorter than that of the source electrode and a length of the second protective pattern is shorter than that of the drain electrode; and wherein in a direction perpendicular to the extending direction the first inner fringe of the first protective pattern is substantially aligned to an inner fringe of the source electrode and the second inner fringe of the second protective pattern is substantially aligned to an inner fringe of the drain electrode.