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

Abstract

To improve characteristics of an oxide semiconductor thin film transistor.SOLUTION: An oxide semiconductor thin film transistor device includes a gate electrode part, an oxide semiconductor part, a first source / drain electrode part, and a second source / drain electrode part. The oxide semiconductor part has a concentration distribution of elements capable of making an oxide semiconductor high in resistance. The concentration distribution shows a first concentration at a gravity center position of a channel region overlapping with a gate electrode part in plan view, and also shows a concentration higher than the first concentration nearby at least a part of a border defining an outer peripheral end of the channel region.SELECTED DRAWING: Figure 7

Claims

1. An oxide semiconductor thin film transistor device, a gate electrode portion; an oxide semiconductor portion; a first source / drain electrode portion; a second source / drain electrode portion; Including, the oxide semiconductor portion has a concentration distribution of an element that can increase the resistance of the oxide semiconductor; The concentration distribution is a first concentration is exhibited at a center position of a channel region overlapping with the gate electrode portion in a plan view, a concentration higher than the first concentration in the vicinity of at least a portion of a boundary that defines an outer circumferential edge of the channel region; Oxide semiconductor thin film transistor device.

2. 2. The oxide semiconductor thin film transistor device according to claim 1, the oxide semiconductor portion includes a first source / drain region on the first source / drain electrode portion side outside the channel region, the concentration distribution exhibits a concentration higher than the first concentration in the first source / drain region near a boundary of the channel region; Oxide semiconductor thin film transistor device.

3. 2. The oxide semiconductor thin film transistor device according to claim 1, The element is one selected from oxygen, fluorine, nitrogen and sulfur. Oxide semiconductor thin film transistor device.

4. 2. The oxide semiconductor thin film transistor device according to claim 1, the gate electrode portion is a top gate electrode portion; Oxide semiconductor thin film transistor device.

5. 3. The oxide semiconductor thin film transistor device according to claim 2, the oxide semiconductor portion includes a second source / drain region on the second source / drain electrode portion side outside the channel region, the concentration distribution exhibits a higher concentration in the second source / drain region near a boundary of the channel region than the first concentration; Oxide semiconductor thin film transistor device.

6. 3. The oxide semiconductor thin film transistor device according to claim 2, the element is oxygen, the concentration distribution exhibits a higher concentration in the first source / drain region near the boundary of the channel region than in a region in contact with the first source / drain electrode portion; Oxide semiconductor thin film transistor device.

7. 2. The oxide semiconductor thin film transistor device according to claim 1, the concentration distribution exhibits a concentration higher than the first concentration in the vicinity of both ends defining a channel width in the channel region; Oxide semiconductor thin film transistor device.

8. 2. The oxide semiconductor thin film transistor device according to claim 1, a gate insulating layer between the gate electrode portion and the oxide semiconductor portion; In the gate insulator layer, an oxygen concentration in a region outside the gate electrode portion in a plan view is higher than an oxygen concentration in a region overlapping with the gate electrode portion in a plan view. Oxide semiconductor thin film transistor device.

9. 2. The oxide semiconductor thin film transistor device according to claim 1, further including an insulator layer below the oxide semiconductor portion; the gate electrode portion is located above the oxide semiconductor portion, In the insulator layer, the oxygen concentration in a region outside the gate electrode portion in a plan view is higher than the oxygen concentration in a region overlapping with the gate electrode portion in a plan view. Oxide semiconductor thin film transistor device.

10. 2. The oxide semiconductor thin film transistor device according to claim 1, the gate electrode portion is a top gate electrode portion located above the oxide semiconductor portion, an insulating layer below the oxide semiconductor portion; a bottom gate electrode portion under the insulating layer, the bottom gate electrode portion having a pattern longer than the top gate electrode portion in a channel length direction; In the insulating layer, the oxygen concentration in the region outside the bottom gate electrode portion in plan view is the oxygen concentration in a region that overlaps with the bottom gate electrode portion but does not overlap with the top gate electrode portion in a plan view is equal to the oxygen concentration in the region that overlaps with the bottom gate electrode portion but does not overlap with the top gate electrode portion, the oxygen concentration is higher than the oxygen concentration in a region overlapping with the bottom gate electrode portion and the top gate electrode portion in a plan view; Oxide semiconductor thin film transistor device.

11. 2. The oxide semiconductor thin film transistor device according to claim 1, the gate electrode portion is a top gate electrode portion located above the oxide semiconductor portion, an insulating layer below the oxide semiconductor portion; a bottom gate electrode portion under the insulating layer, the bottom gate electrode portion having a pattern shorter than the top gate electrode portion in a channel length direction; In the insulating layer, an oxygen concentration in a region outside the bottom gate electrode portion and the top gate electrode portion in a planar view is higher than an oxygen concentration in a region that does not overlap with the bottom gate electrode portion in a planar view but overlaps with the top gate electrode portion, and an oxygen concentration in a region that overlaps with the bottom gate electrode portion and the top gate electrode portion in a planar view. Oxide semiconductor thin film transistor device.

12. A method for manufacturing an oxide semiconductor thin film transistor device, comprising: forming an oxide semiconductor layer; forming a gate electrode portion; implanting an element capable of increasing the resistance of the oxide semiconductor into a selected region of the oxide semiconductor layer; forming a first source / drain electrode and a second source / drain electrode; a method for manufacturing an oxide semiconductor thin film transistor device, the method comprising:

13. 13. A method for manufacturing an oxide semiconductor thin film transistor device according to claim 12, comprising: the selected region is located outside the gate electrode portion; The element is implanted using the gate electrode portion as a mask. A method for manufacturing an oxide semiconductor thin film transistor device.

14. 13. A method for manufacturing an oxide semiconductor thin film transistor device according to claim 12, comprising: The element is selected from oxygen, fluorine, nitrogen and sulfur. A method for manufacturing an oxide semiconductor thin film transistor device.

15. 13. A method for manufacturing an oxide semiconductor thin film transistor device according to claim 12, comprising: the implantation of the element is performed before forming the first source / drain electrode and the second source / drain electrode. A method for manufacturing an oxide semiconductor thin film transistor device.

16. 13. A method for manufacturing an oxide semiconductor thin film transistor device according to claim 12, comprising: the selected region is a region near both ends defining a channel width in a channel region overlapping with the gate electrode portion; A method for manufacturing an oxide semiconductor thin film transistor device.

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