Hydrogenated p-channel metal oxide semiconductor thin film transistors

Patent metadata

Field	Value
Publication number	US-9985139-B2
Application number	US-201514863289-A
Country	US
Kind code	B2
Filing date	Sep 23, 2015
Priority date	Nov 12, 2014
Publication date	May 29, 2018
Grant date	May 29, 2018

Abstract

This disclosure provides p-type metal oxide semiconductor materials that display good thin film transistor (TFT) characteristics. Also provided are TFTs including channels that include p-type oxide semiconductors, and methods of fabrication. The p-type metal oxide films may be hydrogenated such that they have a hydrogen content of at least 10 18 atoms/cm 3 , and in some implementations, at least 10 20 atoms/cm 3 , or higher. Examples of hydrogenated p-type metal oxide films include hydrogenated tin (II)-based films and hydrogenated copper (I)-based films. The TFTs may be characterized by having one or more TFT characteristics such as high mobility, low subthreshold swing (s-value), and high on/off current ratio.

First claim

What is claimed is:

1. A method, comprising:
providing a substrate;
forming a p-type metal oxide semiconductor layer on the substrate; and
annealing the p-type metal oxide semiconductor layer in a hydrogen (H 2 )-containing atmosphere to form a hydrogenated p-type metal oxide semiconductor layer, wherein annealing the p-type metal oxide semiconductor layer in a hydrogen (H 2 )-containing atmosphere terminates metal cation vacancies (V M ) and wherein the hydrogenated p-type metal oxide semiconductor layer has a hydrogen concentration of at least 10 18 atoms/cm 3 .

2. The method of claim 1 , wherein the p-type metal oxide semiconductor layer is a Sn (II)-based oxide semiconductor layer.

3. The method of claim 1 , wherein the p-type metal oxide semiconductor layer is a Cu (I)-based oxide semiconductor layer.

4. The method of claim 1 , wherein the p-type metal oxide semiconductor of the p-type metal oxide semiconductor layer is one of a compound in a group consisting of doped or undoped Cu 2 O, CuO, SnO, NiO, PbO, Ag 2 O, Mn 3 O 4 , ZnRh 2 O 4 , SrCu 2 O 2 , CuWO 4 , and Ln—Ru—O compounds where Ln is any lanthanide except cerium (Ce).

5. The method of claim 1 , wherein the p-type metal oxide semiconductor of the p-type metal oxide semiconductor layer is selected from p-type copper delafossites of the formula CuMO 2 , where M is a metal.

6. The method of claim 1 , wherein the p-type metal oxide semiconductor of the p-type metal oxide semiconductor layer is an ABO 2 oxide characterized by a delafossite crystal structure.

7. The method of claim 1 , wherein forming the hydrogenated p-type metal oxide semiconductor layer includes depositing the p-type metal oxide semiconductor layer in a hydrogen (H 2 )-containing atmosphere.

8. The method of claim 1 , further comprising forming a gate electrode and a gate dielectric, wherein the gate dielectric is between the p-type metal oxide semiconductor layer and the gate electrode.

9. The method of claim 1 , wherein the hydrogenated p-type metal oxide semiconductor layer has a hydrogen concentration of at least 10 19 atoms/cm 3 .

10. The method of claim 1 , wherein the hydrogenated p-type metal oxide semiconductor layer has a hydrogen concentration of at least 10 20 atoms/cm 3 .

11. The method of claim 1 , wherein the hydrogenated p-type metal oxide semiconductor layer has a hydrogen concentration of at least 10 21 atoms/cm 3 .

12. The method of claim 5 , wherein M is a Group IIIA or IIIB metal.

13. The method of claim 1 , wherein annealing the p-type metal oxide semiconductor layer in a hydrogen (H 2 )-containing atmosphere terminates dangling bond defects in the p-type metal oxide semiconductor layer.

14. The method of claim 2 , wherein annealing the p-type metal oxide semiconductor layer in a hydrogen (H 2 )-containing atmosphere terminates tin vacancies (V Sn ) and oxygen vacancies (V O ).

15. The method of claim 1 , further comprising breaking hydrogen bonds in a dielectric layer that overlies or underlies the p-type metal oxide semiconductor layer to allow hydrogen in the dielectric layer to diffuse into the p-type metal oxide semiconductor layer.

16. The method of claim 1 , wherein annealing the p-type metal oxide semiconductor layer in a hydrogen (H 2 )-containing atmosphere terminates oxygen vacancies (V O ).

17. The method of claim 1 , wherein most of the hydrogen incorporated into the p-type metal oxide semiconductor layer during the annealing terminates the metal cation vacancies (V M ).

Assignees

• Qualcomm Inc

Inventors

• Nomura Kenji

Classifications

• H10P14/38

  characterised by treatments done after the formation of the materials · CPC title

• H01L29/7869 Primary

  Electricity · mapped topic

• H01L29/66742

  Electricity · mapped topic

• H01L29/66969

  Electricity · mapped topic

• G09G3/2096

  Details of the interface to the display terminal specific for a flat panel (suitable for both CRT and flat panel G09G5/006; specific for a CRT G09G1/167) · CPC title