Manufacture method of TFT substrate and manufactured TFT substrate

Patent metadata

Field	Value
Publication number	US-10038074-B2
Application number	US-201615105572-A
Country	US
Kind code	B2
Filing date	Apr 26, 2016
Priority date	Mar 23, 2016
Publication date	Jul 31, 2018
Grant date	Jul 31, 2018

Abstract

The present invention provides a manufacture method of a TFT substrate and a manufactured TFT substrate. By locating the first channel region and the first lightly doped offset region between the first source and the drain, and locating the second channel region and the second lightly doped offset region between the second source and the drain, and forming the first overlapping region and the second overlapping region respectively between the drain and the gate and between the second source and the gate, thus, the paths of the current flowing from the first, the second sources to the drain and the current flowing from the drain to the first, the second sources are the same. Namely, the current path from source to the drain and the current path from the drain to the source are the same. According, the symmetry of the TFT structure is realized.

First claim

What is claimed is:

1. A manufacture method of a TFT substrate, comprising steps of:
step 1, providing a substrate, and forming a gate on the substrate, and the gate is a U shape structure, comprising a first vertical part, a second vertical part and a transverse connecting part, connecting corresponding end parts of the first vertical part and the second vertical part;
step 2, depositing a gate isolation layer on the gate and the substrate, and depositing amorphous silicon on the gate isolation layer to obtain an amorphous silicon film, and employing a low temperature crystallization process to convert the amorphous silicon film into a polysilicon film, and employing one mask for patterning the polysilicon film to obtain an active layer;
step 3, implementing ion light doping to the entire active layer; implementing ion heavy doping to a partial region of the active layer to form a drain contact region corresponding to the partial region and a first source contact region and a second source contact region, which are respectively located at two sides of the drain contact region and spaced with the same with a certain distance;
wherein a left side of the drain contact region overlaps with a right part of the first vertical part of the gate; a left side of the second source contact region overlaps with the right part of the second vertical part of the gate;
a first lightly doped offset region is formed in a region of the active layer between a left side border of the first source contact region and a left side border of the first vertical part of the gate, a first channel region is formed in a region between a left side border of the first vertical part of the gate and the left side border of the drain contact region, a second lightly doped offset region is formed in a region between a right side border of the drain contact region and a left side border of the second vertical part of the gate, a second channel region is formed in a region between the left side border of the second vertical part of the gate and a left side border of the second source contact region;
step 4, forming a first source, a second source and a drain on the active layer in positions respectively corresponding to the first source contact region, the second source contact region and the drain contact region, and a first overlapping region is formed between a left side of the drain and a right side of the first vertical part of the gate, and a second overlapping region is formed between a left side of the second source and a right side of the second vertical part of the gate;
step 5, depositing a passivation protective layer on the first source, the second source, the drain, the active layer and the gate isolation layer, and employing one mask for patterning the passivation protective layer to respectively form a first via, a second via and a third via correspondingly above the first source, the second source and the drain;
step 6, depositing a conductive layer on the passivation protective layer, and employing one mask for patterning the conductive layer to obtain a first contact electrode, a second contact electrode, a third contact electrode and a connecting wire, and the first contact electrode and the second contact electrode contact with the first source and the second source respectively though the first via and the second via, and the third contact electrode contacts with the drain through the third via;
the connecting wire connects the first contact electrode and the second contact electrode, and the first contact electrode and the second contact electrode respectively contact with the first source and the second source, and then, the first source and the second source are connected to form a U shape source, and thus to make the TFT substrate.

2. The manufacture method of the TFT substrate according to claim 1 , wherein widths of the first channel region and the second channel region are equal, and widths of the first lightly doped offset region and the second lightly doped offset region are equal, and widths of the first overlapping region and the second overlapping region are equal.

3. The manufacture method of the TFT substrate according to claim 1 , wherein in the step 3, N type ion light doping is implementing to the entire active layer, and P type ion light doping is implementing to the active layer in positions corresponding to the first source contact region, the second source contact region and the drain contact region; or P type ion light doping is implementing to the entire active layer, and N type ion light doping is implementing to the active layer in positions corresponding to the first source contact region, the second source contact region and the drain contact region.

4. The manufacture method of the TFT substrate according to claim 1 , wherein a manufacture method of the gate is: depositing a metal layer on the substrate, and employing one mask for patterning the metal layer to obtain the gate; or is: forming a polysilicon layer on the substrate, and after implementing N type doping to the polysilicon layer, employing one mask for patterning the N type doping polysilicon layer to obtain the gate;
a manufacture method of the first source, the second source and the drain is:
depositing a metal layer on the active layer and the gate isolation layer, and employing one mask for patterning the metal layer to obtain the first source, the second source and the drain; or is: forming a polysilicon layer on the active layer and the gate isolation layer, and after implementing N type doping to the polysilicon layer, employing one mask for patterning the N type doping polysilicon layer to obtain the first source, the second source and the drain.

5. The manufacture method of the TFT substrate according to claim 1 , wherein all materials of the first contact electrode, the second contact electrode, the third contact electrode, and the connecting wire are transparent conductive metal oxide substance.

6. A TFT substrate, comprising a substrate, a gate located on the substrate, a gate isolation layer located on the gate and the substrate, an active layer located on the gate isolation layer, a first source, a second source and a drain located on the active layer, a passivation protective layer located on the first source, the second source, the drain, the active layer and the gate isolation layer, and a first contact electrode, a second contact electrode, a third contact electrode and a connecting wire;
the gate is a U shape structure, comprising a first vertical part, a second vertical part and a transverse connecting part, connecting corresponding end parts of the first vertical part and the second vertical part;
the active layer comprises a drain contact region and a first source contact region and a second source contact region, which are respectively located at two sides of the drain contact region and spaced with the same with a certain distance;
a first lightly doped offset region is formed in a region of the active layer between a left side border of the first source contact region and a left side border of the first vertical part of the gate, a first channel region is formed in a region between a left side border of the first vertical part of the gate and the left side border of the drain contact region, a second lightly doped offset region is formed in a region between a right side border of the drain contact region and a left side border of the second vertical part of the gate, a second channel region is formed in a region between the left side border of the second vertical part of the gate and a left side border of the second source contact region;
the first source, the second source and the drain are located on the active layer respectively corresponding to the first source contact region, the second source contac

Assignees

• Shenzhen China Star Optoelect

Inventors

• Chi Shipeng

Classifications

• H10P14/3802

  Crystallisation or recrystallisation of non-monocrystalline semiconductor materials, e.g. regrowth · CPC title

• H10D84/01

  Manufacture or treatment · CPC title

• H01L21/02667

  Electricity · mapped topic

• H01L29/786

  Electricity · mapped topic

• H01L29/6675 Primary

  Electricity · mapped topic