Microelectronic device

• US 20090035899A1
• Filed: 07/31/2007
• Published: 02/05/2009
• Est. Priority Date: 07/31/2007
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Herman, Gregory, Hoffman, Randy, Yamashita, Tsuyoshi, Smith, J. Daniel
• Granted Patent: US 8,058,096 B2
• Time in Patent Office: Days
• US Class Current: 438/151
• 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 29/7869 having a semiconductor body comprising an oxide semiconductor material, e.g. zinc oxide, copper aluminium oxide, cadmium stannate

Abstract

A thin film transistor is manufactured by a process including forming an oxide semiconductor channel, patterning the oxide semiconductor channel with a photolithographic process, and exposing the patterned oxide semiconductor channel to an oxygen containing plasma.

Claims

1. A method of making a thin film transistor, comprising:

forming an oxide semiconductor channel;

patterning said oxide semiconductor channel with a photolithographic process to form a patterned oxide semiconductor channel; and

exposing said patterned oxide semiconductor channel to an oxygen containing plasma.

2. The method of claim 1 further comprising, prior to exposing said patterned oxide semiconductor channel to an oxygen containing plasma, annealing said patterned oxide semiconductor channel in air at a temperature of at least one hundred and fifty degrees Celsius.

3. The method of claim 1 further comprising, after exposing said patterned oxide semiconductor channel to an oxygen containing plasma, annealing said patterned oxide semiconductor channel in air at a temperature of at least one hundred and fifty degrees Celsius.

4. The method of claim 1 further comprising forming a source and a drain, wherein said oxide semiconductor layer connects said source and said drain.

5. The method of claim 1 wherein said oxide semiconductor layer is formed on a gate dielectric.

6. The method of claim 1 wherein said exposing said patterned oxide semiconductor channel to said oxygen containing plasma is conducted for a time of at least two minutes, at an energy level of at least 900 Watts, at a oxygen containing gas flow rate of at least 30 sccm, and at a pressure of at least 40 mTorr.

7. The method of claim 1 wherein said photolithographic process is chosen from one of an etch photolithographic process and a lift-off photolithographic process.

8. The method of claim 1 wherein said oxide channel semiconductor channel is formed by rf sputtering and defines a thickness in a range of 10 nm to 200 nm.

9. The method of claim 2 wherein said annealing is conducted for at least fifty minutes.

10. The method of claim 3 wherein said annealing is conducted for at least fifty minutes.

11. The method of claim 1, wherein said oxide semiconductor channel comprises an oxide with cations selected from at least one of Zn, In, Ga, and Sn.

12. The method of claim 1, wherein said oxide semiconductor channel comprises zinc indium oxide.

13. The method of claim 12, wherein said zinc indium oxide comprises a Zn:

In atomic ratio in a range of 5;

1 to 1;

5.

14. The method of claim 12, wherein said zinc indium oxide comprises a Zn:

In atomic ratio of 1;

4.

15. A thin film transistor manufactured by the process comprising:

forming an oxide semiconductor channel;

patterning said oxide semiconductor channel with a photolithographic process to form a patterned oxide semiconductor channel; and

exposing said patterned oxide semiconductor channel to an oxygen containing plasma.

16. The transistor of claim 15 wherein said oxide semiconductor channel is chosen from one of zinc oxide, tin oxide, indium oxide, gallium oxide, zinc indium oxide, zinc tin oxide, indium gallium oxide, zinc indium gallium oxide, and a combination thereof.

17. The transistor of claim 15 further manufactured by the process comprising annealing said patterned oxide semiconductor channel before and after exposing said patterned oxide semiconductor channel to an oxygen containing plasma.