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US 2002/0160547 A1Published application
Transistor and associated driving device
AssigneeHannstar Display Corp.
InventorPo-Sheng Shih
Life of this patent
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Abstract
A method of forming a thin film transistor and its associated driver. A polysilicon layer, a gate oxide layer and a gate layer are formed on a substrate. A photoresist layer comprising of a top section and a base section is formed over the gate layer. The top section of the photoresist layer patterns out a thin film transistor gate while the base section outside the top section patterns out a lightly doped region or undoped region on each side of the gate. Complementary metal-oxide-semiconductor drivers are formed on each side of the thin film transistor.
Claims21
A method of forming a thin film transistor, comprising:
- providing a substrate,
- sequentially forming a polysilicon layer, a gate oxide layer and a gate layer over the substrate;
- forming a photoresist layer over the gate layer, wherein the photoresist layer includes a base section and a top section with a width of the base section being greater than a width of the top section;
- removing a portion of the gate layer to expose the gate oxide layer while using the photoresist layer as a mask;
- conducting an ion implantation to form a first doped region in the polysilicon layer while using the photoresist layer as a mask;
- removing a portion of the photoresist layer such that photoresist material in the base section and outside the top section is completely removed, exposing the gate layer underneath and removing a pre-defined thickness of photoresist material from the top section,
- removing the exposed gate layer to form a gate electrode;
- and
- forming an undoped region on each side of the gate electrode.
6 more elements
A method of forming a thin film transistor and its associated driver, comprising:
- providing a substrate, wherein the substrate is divided into a first type thin film transistor region, a second type thin film transistor region and a pixel thin film transistor region,
- forming a patterned polysilicon layer over the substrate;
- sequentially forming a gate oxide layer and a gate layer over the patterned polysilicon layer and the substrate;
- forming a patterned first photoresist layer over the first type thin film transistor region, the second type thin film transistor region and the pixel thin film transistor region;
- removing a portion of the gate layer to form a first type thin film transistor gate while using the first photoresist layer as a mask;
- conducting a first ion implantation to form a first doped region in the polysilicon layer on each side of the first type thin film transistor gate;
- removing the first photoresist layer;
- forming a patterned second photoresist layer over the second type thin film transistor region, the pixel thin film transistor region and the first type thin film transistor region, wherein the second photoresist layer over the pixel thin film transistor region includes a top section and a base section with a width of the base section being greater than a width of the top section;
- removing a portion of the gate layer to expose the gate oxide layer while using the second photoresist layer as a mask;
- conducting a second ion implantation to form a second doped region in the polysilicon layer using the second photoresist layer as a mask;
- removing a portion of the second photoresist layer such that photoresist material in the base section outside the top section is completely removed, exposing the gate layer underneath and removing a pre-defined thickness of photoresist material from the top section, and
- removing the exposed gate layer to form a pixel thin film transistor gate electrode.
9 more elements
A method of forming a thin film transistor and its associated driver, comprising:
- providing a substrate, wherein the substrate is divided into a first type thin film transistor region, a second type thin film transistor region and a pixel thin film transistor region;
- forming a patterned polysilicon layer over the substrate;
- sequentially forming a gate oxide layer and a gate layer over the patterned polysilicon layer and the substrate;
- forming a patterned first photoresist layer over the second type thin film transistor region, the pixel thin film transistor region and the first type thin film transistor region, wherein the first photoresist layer over the pixel thin film transistor region includes a top section and a base section with a width of the base section being greater than a width of the top section;
- removing a portion of the gate layer to expose the gate oxide layer while using the first photoresist layer as a mask;
- conducting a first ion implantation to form a first doped region in the polysilicon layer while using the first photoresist layer as a mask;
- removing a portion of the first photoresist layer such that photoresist material in the base section outside the top section is completely removed, exposing the gate layer underneath and a pre-defined thickness of photoresist material is removed from the top section,
- removing the exposed gate layer to form a pixel thin film transistor gate electrode;
- removing the first photoresist layer;
- forming a patterned second photoresist layer over the first type thin film transistor region, the second type thin film transistor region and the pixel thin film transistor region;
- removing a portion of the gate layer to form a first type thin film transistor gate using the second photoresist layer as a mask;
- and
- conducting a second ion implantation to form a second doped region on each side of the first type thin film transistor gate
10 more elements
Dependencies are inferred from the claim text.