Oxide semiconductor thin-film transistor device and method of manufacturing the same

Patent metadata

Field	Value
Publication number	US-12490473-B2
Application number	US-202218074756-A
Country	US
Kind code	B2
Filing date	Dec 5, 2022
Priority date	Dec 8, 2021
Publication date	Dec 2, 2025
Grant date	Dec 2, 2025

Abstract

An oxide semiconductor thin-film transistor device includes a gate electrode region, an oxide semiconductor region, a first source/drain electrode region, and a second source/drain electrode region. The oxide semiconductor region has a concentration distribution of an element capable of increasing resistance of an oxide semiconductor. The concentration distribution shows a first concentration at the centroid of a channel region overlapping the gate electrode region in a planar view. The concentration distribution shows a concentration higher than the first concentration in a vicinity of at least a part of a boundary defining an outer end of the channel region.

First claim

What is claimed is:

1 . An oxide semiconductor thin-film transistor device comprising:
a gate electrode region; an oxide semiconductor region; a first source/drain electrode region; and a second source/drain electrode region, wherein the oxide semiconductor region has a concentration distribution of an element capable of increasing resistance of an oxide semiconductor, wherein the concentration distribution shows a first concentration at the centroid of a channel region overlapping the gate electrode region in a planar view, wherein the concentration distribution shows a concentration higher than the first concentration in a vicinity of at least a part of a boundary defining an outer end of the channel region, wherein the oxide semiconductor region includes a first source/drain region located outer than the boundary of the channel region and on a side of the first source/drain electrode region, wherein the concentration distribution in the first source/drain region shows a concentration higher than the first concentration in a vicinity of the boundary of the channel region, wherein the element is oxygen, and wherein the concentration distribution in the first source/drain region shows a higher concentration in a vicinity of the boundary of the channel region than in a region in contact with the first source/drain electrode region.

2 . The oxide semiconductor thin-film transistor device according to claim 1 ,
wherein the concentration distribution in the channel region shows a concentration higher than the first concentration in vicinities of ends defining a channel width.

3 . The oxide semiconductor thin-film transistor device according to claim 1 , further comprising:
a gate insulating layer between the gate electrode region and the oxide semiconductor region, wherein, in the gate insulating layer, an oxygen concentration in a region outside the gate electrode region in a planar view is higher than an oxygen concentration in a region overlapping the gate electrode region in the planar view.

4 . An oxide semiconductor thin-film transistor device comprising:
a gate electrode region; an oxide semiconductor region; a first source/drain electrode region; and a second source/drain electrode region, wherein the oxide semiconductor region has a concentration distribution of an element capable of increasing resistance of an oxide semiconductor, wherein the concentration distribution shows a first concentration at the centroid of a channel region overlapping the gate electrode region in a planar view, wherein the concentration distribution shows a concentration higher than the first concentration in a vicinity of at least a part of a boundary defining an outer end of the channel region, wherein the gate electrode region is a top-gate electrode region located upper than the oxide semiconductor region, wherein the oxide semiconductor thin-film transistor device further comprises:
an insulating layer under the oxide semiconductor region; and
a bottom-gate electrode region under the insulating layer, the bottom-gate electrode region being a pattern longer in length in a direction along a channel length than the top-gate electrode region, and
wherein, in the insulating layer, a concentration of the element capable of increasing resistance of an oxide semiconductor in a region outside the bottom-gate electrode region in a planar view is equal to a concentration of the element capable of increasing resistance of an oxide semiconductor, in a region overlapping the bottom-gate electrode region but not overlapping the top-gate electrode region in the planar view and higher than a concentration of the element capable of increasing resistance of an oxide semiconductor in a region overlapping both the bottom-gate electrode region and the top-gate electrode region in the planar view.

5 . The oxide semiconductor thin-film transistor device according to claim 4 , wherein the element is an element selected from a group consisting of oxygen, fluorine, nitrogen, and sulfur.

6 . An oxide semiconductor thin-film transistor device comprising:
a gate electrode region; an oxide semiconductor region; a first source/drain electrode region; and a second source/drain electrode region, wherein the oxide semiconductor region has a concentration distribution of an element capable of increasing resistance of an oxide semiconductor, wherein the concentration distribution shows a first concentration at the centroid of a channel region overlapping the gate electrode region in a planar view, wherein the concentration distribution shows a concentration higher than the first concentration in a vicinity of at least a part of a boundary defining an outer end of the channel region, wherein the gate electrode region is a top-gate electrode region located upper than the oxide semiconductor region, wherein the oxide semiconductor thin-film transistor device further comprises:
an insulating layer under the oxide semiconductor region; and
a bottom-gate electrode region under the insulating layer, the bottom-gate electrode region being a pattern shorter in length in a direction along a channel length than the top-gate electrode region, and
wherein, in the insulating layer, a concentration of the element capable of increasing resistance of an oxide semiconductor in a region outside both the bottom-gate electrode region and the top-gate electrode region in a planar view is higher than a concentration of the element capable of increasing resistance of an oxide semiconductor in a region not overlapping the bottom-gate electrode region but overlapping the top-gate electrode region in the planar view and a concentration of the element capable of increasing resistance of an oxide semiconductor in a region overlapping both the bottom-gate electrode region and the top-gate electrode region in the planar view.

7 . The oxide semiconductor thin-film transistor device according to claim 6 , wherein the element is an element selected from a group consisting of oxygen, fluorine, nitrogen, and sulfur.

Assignees

• Xiamen Tianma Display Tech Co Ltd

Inventors

• Tanaka Jun
• Takechi Kazushige
• Sera Kenji

Classifications

• H10P30/22

  using masks · CPC title

• H10P30/204

  into Group IV semiconductors · CPC title

• H10D99/00 Primary

  Subject matter not provided for in other groups of this subclass · CPC title

• H10D30/6757

  characterised by the structure of the channel, e.g. transverse or longitudinal shape or doping profile (TFTs having channel structures for preventing kink or snapback effects H10D30/6708; TFTs having lightly-doped source or drain extensions H10D30/6715) · CPC title

• H10D30/6734

  having gate electrodes arranged on both top and bottom sides of the channel, e.g. dual-gate TFTs · CPC title