METHOD FOR SURFACE TREATMENT ON A METAL OXIDE AND METHOD FOR PREPARING A THIN FILM TRANSISTOR

• US 20130171836A1
• Filed: 08/22/2012
• Published: 07/04/2013
• Est. Priority Date: 12/28/2011
• Status: Active Grant

• Current Assignee: BOE Technology Group Co., Ltd.
• Original Assignee: BOE Technology Group Co., Ltd.
• Inventors: Liu, Xiaodi, Cheng, Jun
• Granted Patent: US 8,940,647 B2
• Time in Patent Office: Days
• US Class Current: 438/768
• CPC Class Codes: H01L 21/0234 treatment by exposure to a plasma
• CPC Class Codes: H01L 21/425 producing ion implantation
• CPC Class Codes: H01L 21/443 from a gas or vapour, e.g. condensation
• CPC Class Codes: H01L 21/465 Chemical or electrical treatment, e.g. electrolytic etching to form insulating layers H01L21/469
• CPC Class Codes: H01L 29/66742 Thin film unipolar transistors
• CPC Class Codes: H01L 29/66969 of devices having semiconductor bodies not comprising group 14 or group 13/15 materials comprising selenium or tellurium in uncombined form other than as impurities in semiconductor bodies of other materials, comprising cuprous oxide or cuprous iodide H01L21/02365
• CPC Class Codes: H01L 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• CPC Class Codes: H01L 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate
• CPC Class Codes: H01L 31/022466 made of transparent conductive layers, e.g. TCO, ITO layers
• CPC Class Codes: H01L 31/022483 composed of zinc oxide [ZnO]

Abstract

Embodiments of the present invention provide a method for surface treatment on a metal oxide and a method for preparing a thin film transistor. The method for surface treatment on a metal oxide comprises: utilizing plasma to perform a surface treatment on a device to be processed; the plasma comprises a mixture gas of an F-based gas and O₂, and the device to be processed is a metal oxide or a manufactured article coated with a metal oxide. The embodiments provided by the present invention can reduce the contact resistance between a metal oxide and other electrodes, and improve the effect of ohmic contact of the metal oxide.

Claims

1. A method for surface treatment on a metal oxide, comprising:

utilizing plasma to perform a surface treatment on a device to be processed;

wherein the plasma comprises a mixture gas of an F-based gas and O₂, and the device to be processed is a metal oxide layer or a manufactured article coated with the metal oxide.

2. The method for surface treatment on a metal oxide according to claim 1, wherein the metal oxide comprises zinc oxide, tin oxide, zinc oxide based metal oxide containing at least one element of indium, aluminum and gallium, or tin oxide-based metal oxide containing at least one element of the indium, aluminum and gallium.

3. The method for surface treatment on a metal oxide according to claim 1, wherein the utilizing plasma to perform a surface treatment on a device to be processed comprises:

filling a chamber, in which the device to be processed is placed, with the mixture gas of an F-based gas and O₂ at pressure Y, the O₂ content in the mixture gas being r;

utilizing RF at a power P to act on the mixture gas to obtain plasma; and

the time in which the plasma acts on the device to be processed is “

t”

.

4. The method for surface treatment on a metal oxide according to claim 1, wherein the F-based gas comprises at least one gas of CF₄, SF₆, NF₃ and C₂F₈.

5. The method for surface treatment on a metal oxide according to claim 4, wherein the F-based gas is CF₄;

wherein the O₂ content η

in the mixture gas of CF₄ and O₂ is in a range of 0-38%;

the pressure Y of the mixture gas of CF₄ and O₂ is in a range of 40-400 mTorr;

the time “

t”

in which the plasma acts on the device to be processed is in a range of 5-120 s; and

the power P of the RF is in a range of 200-1500 W.

6. A method for preparing a thin film transistor, comprising:

preparing a gate electrode, a gate insulating layer, a channel layer, a blocking layer, a source electrode, a drain electrode and a passivation protective layer on a substrate in order, preparation of the channel layer comprising;

utilizing plasma to perform surface treatment on the channel layer;

the plasma comprises a mixture gas of an F-based gas and O₂, wherein the material of the channel layer is a metal oxide.

7. The method for preparing a thin film transistor according to claim 6, wherein the metal oxide comprises:

zinc oxide, tin oxide, zinc oxide based metal oxide containing at least one element of indium, aluminum and gallium, or tin oxide-based metal oxide containing at least one element of the indium, aluminum and gallium.

8. The method for preparing a thin film transistor according to claim 6, wherein the utilizing plasma to perform surface treatment on the channel layer comprises:

placing a product, a surface of which is a channel layer, into a chamber filled with a mixture gas of an F-based gas and O₂ at pressure Y, the O₂ content in the mixture gas being η

; and

utilizing RF at a power P to act on the mixture gas to obtain plasma; and

the time in which the plasma acts on the device to be processed is “

t”

.

9. The method for preparing a thin film transistor according to claim 6, wherein the channel layer comprises a central region and two contact regions for contacting the source-drain respectively, the two contact regions being on both sides of the central region;

and

the blocking layer is deposited in the position of the central region on the channel layer, for blocking the plasma from reaching the central region of the channel layer.

10. The method for preparing a thin film transistor according to claim 6, wherein the F-based gas is CF₄;

wherein the O₂ content η

in the mixture gas of CF₄ and O₂ is in a range of 0-38%;

the pressure Y of the mixture gas of CF₄ and O₂ is in a range of 40-400 mTorr;

the time “

t”

in which the plasma acts on the device to be processed is in a range of 5-120 s; and

the power P of the RF is in a range of 200-1500 W.