Field-effect transistor and method for manufacturing the same

• US 7,737,438 B2
• Filed: 07/03/2008
• Issued: 06/15/2010
• Est. Priority Date: 09/15/2006
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Endo, Ayanori, Hayashi, Ryo, Iwasaki, Tatsuya
• Primary Examiner(s): Fahmy; Wael
• Assistant Examiner(s): Ingham; John C
• Application Number:
  US12/167,540
• Publication Number:
  US 20080272370A1
• Time in Patent Office: 712 Days
• Field of Search: 257/43, 257/66, 257/E21.413, 438/151, 438/158, 438/161
• US Class Current: 257/43
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02554 Oxides
• CPC Class Codes: H01L 21/02565 Oxide semiconducting materials not being Group 12/16 materials, e.g. ternary compounds
• CPC Class Codes: H01L 21/02631 Physical deposition at reduced pressure, e.g. MBE, sputtering, evaporation
• CPC Class Codes: H01L 21/265 producing ion implantation
• CPC Class Codes: H01L 21/268 using electromagnetic radiation, e.g. laser radiation
• CPC Class Codes: H01L 21/3003 Hydrogenation or deuterisation, e.g. using atomic hydrogen from a plasma
• CPC Class Codes: H01L 29/45 Ohmic electrodes
• 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 29/78618 characterised by the drain or the source properties, e.g. the doping structure, the composition, the sectional shape or the contact structure silicide contacts, electrodes in general H01L29/458
• 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 method for manufacturing a field-effect transistor includes the steps of forming a source electrode and a drain electrode each containing hydrogen or deuterium; forming an oxide semiconductor layer in which the electrical resistance is decreased if hydrogen or deuterium is added; and, causing hydrogen or deuterium to diffuse from the source electrode and the drain electrode to the oxide semiconductor layer.

Claims

1. A method for manufacturing a field-effect transistor, comprising the steps of:

forming a source electrode and a drain electrode each containing hydrogen or deuterium;

forming an oxide semiconductor layer;

causing hydrogen or deuterium to diffuse from the source electrode and the drain electrode to the oxide semiconductor layer.

2. The method for manufacturing a field-effect transistor according to claim 1, wherein the step of forming a source electrode and a drain electrode each containing hydrogen or deuterium is selected from a step of forming the source electrode and the drain electrode in an atmosphere containing an H₂ gas, a step of forming the source electrode and the drain electrode in an atmosphere containing an H₂O gas, a step of treating the source electrode and the drain electrode with hydrogen plasma after the formation of the source electrode and the drain electrode, and a step of bombarding the source electrode and the drain electrode with accelerated hydrogen ions after the formation of the source electrode and the drain electrode.

3. The method for manufacturing a field-effect transistor according to claim 1, wherein the concentration of hydrogen ions diffused in the step of causing hydrogen or deuterium to diffuse from the source electrode and the drain electrode to the oxide semiconductor layer is in the range of 0.1 to 10 atomic percent in regions in the oxide semiconductor layer in contact with the source electrode and the drain electrode.

4. The method for manufacturing a field-effect transistor according to claim 1, wherein the concentration of hydrogen ions diffused in the step of causing hydrogen or deuterium to diffuse from the source electrode and the drain electrode to the oxide semiconductor layer is in the range of 0.5 to 5 atomic percent in regions in the oxide semiconductor layer in contact with the source electrode and the drain electrode.

5. The method for manufacturing a field-effect transistor according to claim 1, wherein the step of causing hydrogen or deuterium to diffuse from the source electrode and the drain electrode to the oxide semiconductor layer is an annealing step.

6. The method for manufacturing a field-effect transistor according to claim 1, wherein the oxide semiconductor layer is formed of an amorphous oxide material containing In, Ga, and Zn.

7. A field-effect transistor comprising:

an oxide semiconductor layer having a channel region between a source electrode and a drain electrode;

a gate insulator; and

a gate electrode,

wherein the gate insulator is disposed between the gate electrode and the oxide semiconductor layer, and

wherein a concentration of hydrogen or deuterium in regions in the oxide semiconductor layer in contact with the source electrode and the drain electrode is higher than a concentration of hydrogen or deuterium in the channel region.

8. The field-effect transistor according to claim 7, wherein the hydrogen-ion concentration of the regions in the oxide semiconductor layer in contact with the source electrode and the drain electrode is in the range of 0.1 to 10 atomic percent.

9. The field-effect transistor according to claim 7, wherein the hydrogen-ion concentration of the regions in the oxide semiconductor layer in contact with the source electrode and the drain electrode is in the range of 0.5 to 5 atomic percent.

10. The field-effect transistor according to claim 7, wherein the oxide semiconductor layer is formed of an amorphous oxide material containing In, Ga, and Zn.

11. A display apparatus comprising display devices, and having a field-effect transistor according to claim 7, wherein electrodes of each of the display devices are electrically connected to the source electrode or the drain electrode of the field-effect transistor.

12. The display apparatus according to claim 11, wherein the display devices are electroluminescent devices.

13. The display apparatus according to claim 11, wherein the display devices are liquid crystal cells.

14. The display apparatus according to claim 11, wherein a plurality of display devices and a plurality of field-effect transistors are two-dimensionally arranged on a substrate.