Thin film transistor, method for manufacturing the same, and display device using the same

A display device comprising:

• a substrate;
• a semiconductor layer provided on the substrate and crystallized by using a metal catalyst;
• a gate electrode insulated from and disposed on the semiconductor layer;
• a getter layer disposed between the semiconductor layer and the gate electrode and formed with a metal oxide having a diffusion coefficient that is less than a diffusion coefficient of the metal catalyst in the semiconductor layer;
• a source electrode contacting a source region of the semiconductor layer and spaced apart from the gate electrode;
• and
• a drain electrode contacting a drain region of the semiconductor layer and spaced apart from the gate electrode and the source electrode.

A method for manufacturing a thin film transistor comprising:

• providing a substrate;
• forming an amorphous silicon layer on the substrate;
• forming a polysilicon layer by crystallizing the amorphous silicon layer by use of a metal catalyst;
• forming a semiconductor layer by patterning the polysilicon layer;
• forming a gate insulating layer on the semiconductor layer;
• forming a plurality of gettering holes on the gate insulating layer;
• forming a gettering metal layer on the gate insulating layer to contact the semiconductor layer through the plurality of gettering holes;
• and
• forming a getter layer while oxidizing the gettering metal layer through a heat treatment process, such that the getter layer is formed with a metal oxide having a diffusion coefficient that is less than a diffusion coefficient of the metal catalyst included in the semiconductor layer, and reducing a density of metal catalyst included in the semiconductor layer.

A method for manufacturing a thin film transistor comprising:

• providing a substrate;
• forming an amorphous silicon layer on the substrate;
• forming a polysilicon layer by crystallizing the amorphous silicon layer by use of a metal catalyst;
• coating an insulation material on the polysilicon layer;
• forming a semiconductor layer and a gate insulating layer in the same pattern by patterning the polysilicon layer and the insulation material;
• forming a gettering metal layer on the gate insulating layer to contact a side of the semiconductor layer;
• and
• forming a getter layer by oxidizing the gettering metal layer through a heat treatment process such that the getter layer is formed with a metal oxide having a diffusion coefficient that is less than a diffusion coefficient of the metal catalyst included in the semiconductor layer, and reducing a density of metal catalyst included in the semiconductor layer.

A method for manufacturing a thin film transistor comprising:

• providing a substrate;
• forming an amorphous silicon layer on the substrate;
• forming a polysilicon layer by crystallizing the amorphous silicon layer by use of a metal catalyst, the polysilicon layer including a residual amount of the metal catalyst;
• forming a gettering metal layer on the polysilicon layer;
• oxidizing the gettering metal layer through a heat treatment process, and reducing a density of the metal catalyst included in the polysilicon layer;
• forming a semiconductor layer and a getter layer in the same pattern by patterning the polysilicon layer and the oxidized gettering metal layer;
• and
• forming a gate insulating layer on the getter layer, wherein
• the getter layer is formed with a metal oxide having a diffusion coefficient that is less than a diffusion coefficient of the metal catalyst in the semiconductor layer.