Microelectronic device

• US 8,058,096 B2
• Filed: 07/31/2007
• Issued: 11/15/2011
• 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: Smith, J. Daniel, Herman, Gregory, Hoffman, Randy, Yamashita, Tsuyoshi
• Primary Examiner(s): MENZ, LAURA MARY
• Application Number:
  US11/888,055
• Publication Number:
  US 20090035899A1
• Time in Patent Office: 1,568 Days
• Field of Search: 438/104, 438/151, 438/158
• US Class Current: 438/104
• 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;

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 an oxygen containing gas flow rate of at least 30 sccm, and at a pressure of at least 40 mTorr.

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

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

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

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

6. 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.

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

8. The method of claim 7, wherein said zinc indium oxide comprises a Zn:

In atomic ratio in a range of 5;

1 to 1;

5.

9. The method of claim 7, wherein said zinc indium oxide comprises a Zn:

In atomic ratio of 1;

4.

10. 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;

annealing said patterned oxide semiconductor channel in air at a temperature of at least 150°

C.; and

then exposing said annealed and patterned oxide semiconductor channel to an oxygen containing plasma;

wherein said annealing is conducted for at least fifty minutes.

12. The method of claim 10, wherein said oxide semiconductor channel comprises an oxide with cations selected from at least one of Zn, In, Ga, and Sn.

13. The method of claim 10, wherein said oxide semiconductor channel comprises zinc indium oxide.

11. 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;

exposing said patterned oxide semiconductor channel to an oxygen containing plasma; and

after exposing said patterned oxide semiconductor channel to said oxygen containing plasma, annealing said patterned oxide semiconductor channel in air at a temperature of at least 150°

C. wherein said annealing is conducted for at least fifty minutes.

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

15. The method of claim 11, wherein said oxide semiconductor channel comprises zinc indium oxide.