Thin film transistor and method of fabricating the same
AssigneeSamsung Mobile Display Co., Ltd.
InventorsTae-Hoon Yang, Ki-Yong Lee, Jin-Wook Seo, Byoung-Keon Park
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Abstract
A thin film transistor and a method of fabricating the same are disclosed. The method includes: sequentially depositing an amorphous silicon layer, a capping layer, and a metal catalyst layer; annealing the entire layer to crystallize the amorphous silicon layer into a polysilicon layer; removing the capping layer; and, when the capping layer is perfectly removed to make a contact angle of the polysilicon layer within a range of about 40 to about 80°, forming a semiconductor layer using the polysilicon layer.
Claims17
A thin film transistor comprising:
- a substrate;
- a semiconductor layer containing a polysilicon material crystallized by an super grain silicon (SGS) crystallization method and disposed over the substrate, wherein the polysilicon material is defined as having a contact angle with a liquid droplet of about 40 to about 80 degrees when the liquid droplet is placed onto a flat surface made of the polysilicon material;
- and
- a gate insulating layer, a gate electrode, an interlayer insulating layer, and source and drain electrode, which are disposed over the semiconductor layer.
A method of making a thin film transistor, the method comprising:
- forming a semiconductor layer over a substrate, the semiconductor layer comprising amorphous silicon;
- forming a capping layer over the semiconductor layer;
- forming a metal catalyst layer over the capping layer, the metal catalyst layer comprising a metal catalyst;
- annealing the substrate, the semiconductor layer, the capping layer, and the metal catalyst layer, such that at least a portion of the metal catalyst diffuses into the semiconductor layer, and such that the amorphous silicon is crystallized into polysilicon;
- removing the metal catalyst layer;
- and
- removing the capping layer from over the semiconductor layer, to an extent that, when a liquid droplet is placed over the semiconductor layer, a contact angle between the semiconductor layer and the liquid droplet is from about 40 degrees to about 80 degrees.
A method of making a display device comprising a thin film transistor (TFT), the method comprising:
- providing an intermediate device comprising a substrate, a polysilicon layer over the substrate, a capping layer over the polysilicon layer;
- removing the capping layer from over the polysilicon layer;
- and
- determining whether the capping layer has been substantially completely removed from over the polysilicon layer, wherein the determining comprises:
- placing a liquid droplet over the polysilicon layer;
- and measuring a contact angle between a baseline of the liquid droplet and a tangential line at a droplet boundary.
Dependencies are inferred from the claim text.