Metal oxide tft stability improvement

Patent metadata

Field	Value
Publication number	US-2015380561-A1
Application number	US-201414765528-A
Country	US
Kind code	A1
Filing date	Feb 5, 2014
Priority date	Mar 1, 2013
Publication date	Dec 31, 2015
Grant date	—

Abstract

A metal oxide thin film transistor incorporating reduced hydrogen silicon-containing layers and methods of making the same are disclosed herein. The thin film transistor can include a substrate, a metal oxide semiconductor layer, a substantially hydrogen free channel interface layer and a cap layer comprising silicon formed over the channel interface layer. The method for making a thin film transistor can include depositing a metal oxide semiconductor layer over a substrate, activating a deposition gas comprising SiF 4 to create an activated deposition gas, delivering the activated deposition gas to the substrate to deposit a channel interface layer comprising SiOF and depositing a cap layer over the channel interface layer and the metal oxide thin film transistor layer.

First claim

1 . A thin film transistor comprising:
a substrate having a first surface; a metal oxide semiconductor layer formed over a portion of the first surface of the substrate; a channel interface layer in contact with the metal oxide semiconductor layer, the channel interface layer comprising silicon oxyfluoride (SiOF), wherein the channel interface layer comprises less than 1 atomic percent hydrogen; and a cap layer formed over the channel interface layer, the cap layer comprising silicon.

2 . The thin film transistor of claim 1 , wherein the cap layer comprises of silicon nitride or silicon oxide.

3 . The thin film transistor of claim 2 , wherein the cap layer comprises of silicon nitride and contains less than 16 atomic percent hydrogen.

4 . The thin film transistor of claim 1 , wherein the hydrogen content of the cap layer is not greater than 1 atomic percent.

5 . The thin film transistor of claim 1 , wherein the channel interface layer comprises more than one layer, and wherein at least one layer of the channel interface comprises SiOF.

6 . The thin film transistor of claim 1 , wherein each of the channel interface layer and the cap layer are between 20 Å and 3000 Å.

7 . The thin film transistor of claim 1 , wherein the cap layer comprises of two or more layers.

8 . The thin film transistor of claim 1 , wherein the metal oxide semiconductor layer is deposited over a gate dielectric layer, the gate dielectric layer consisting of SiOF.

9 . A method for making a thin film transistor comprising:
positioning a substrate in a processing chamber; depositing a metal oxide semiconductor layer over a portion of the surface of the substrate, the metal oxide semiconductor layer comprising zinc oxide; activating a deposition gas to create an activated deposition gas, the deposition gas comprising SiF 4 ; delivering the activated deposition gas to the substrate to deposit a channel interface layer over the metal oxide semiconductor layer, wherein the channel interface layer contains less than 1 atomic percent hydrogen; and depositing a cap layer over the channel interface layer and the metal oxide semiconductor layer.

10 . The method of claim 9 , wherein the channel interface layer is deposited at temperatures less than 250 degrees Celsius.

11 . The method of claim 9 , wherein the cap layer is deposited using a deposition gas mixture comprising SiH 4 , O 2 , N 2 O or combinations thereof.

12 . The method of claim 9 , wherein the cap layer is deposited using a deposition gas mixture comprising SiH 4 , SiF 4 , NH 3 , N 2 , H 2 or combinations thereof.

13 . The method of claim 9 , wherein the channel interface layer comprises less than 1 atomic percent hydrogen.

14 . The method of claim 9 , wherein the cap layer comprises silicon nitride or silicon oxide.

15 . The method of claim 9 , further comprising depositing a gate dielectric layer over the substrate, the gate dielectric layer comprising SiOF.

16 . The method of claim 9 , wherein the channel interface layer is deposited using a deposition gas mixture comprising SiF 4 , O 2 , N 2 O or combinations thereof.

17 . The method of claim 9 , wherein the cap layer is deposited using microwave PECVD.

18 . A thin film transistor comprising:
a substrate having a first surface; a gate electrode formed over the first surface; a gate dielectric layer formed over the gate electrode, the gate dielectric layer comprising SiOF; a metal oxide semiconductor layer formed over the gate dielectric layer, the metal oxide semiconductor layer comprising zinc oxide; a channel interface layer in contact with the metal oxide semiconductor layer, the channel interface layer comprising silicon oxyfluoride (SiOF), wherein the channel interface layer comprises less than 1 atomic percent hydrogen; and a cap layer formed over the channel interface layer, the cap layer comprising silicon nitride or silicon oxide.

19 . The thin film transistor of claim 18 , wherein the cap layer comprises of silicon nitride and contains less than 16 atomic percent hydrogen.

20 . The thin film transistor of claim 18 , wherein each of the channel interface layer and the cap layer are between 20 Å and 3000 Å.

Assignees

• Applied Materials Inc

Inventors

• Won Tae K
• Choi Soo Young
• Yim Dong-Kil
• Park Beom Soo

Classifications

• H10P14/6922

  the material containing Si, O and at least one of H, N, C, F or other non-metal elements, e.g. SiOC, SiOC:H or SiONC · CPC title

• H10P14/3434

  being oxide semiconductor materials (Group IIB-VIA semiconductor materials H10P14/3424) · CPC title

• H10P14/3426

  Oxides · CPC title

• H10P14/24

  using chemical vapour deposition [CVD] · CPC title

• H10D99/00

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