Patent ID: 7651900
Filing Date: 2010-01-26
Classification: B23K,G03F,H01L

Abstract:
1. A method of making a thin film transistor substrate comprising: forming an amorphous silicon layer on an insulating substrate; forming a polysilicon layer by irradiating the amorphous silicon layer with a laser beam through a mask for crystallization, wherein the mask comprises a transmitting area transmitting light and a blocking area that has a metal layer and a semiconductor layer deposited in an alternating manner at least once starting with the metal layer and blocking the light, wherein the mask is disposed such that the laser beam reaches the metal layer before the semiconductor layer, and wherein the crystallization is performed by sequential lateral solidification method; forming a gate insulating layer on the polysilicon layer; forming a gate electrode on the gate insulating layer over the polysilicon layer; forming an inter layer dielectric having contact holes to expose a part of the polysilicon layer on the gate electrode; and forming a source electrode and a drain electrode connected to the part of the polysilicon, respectively, through the contact hole.