Metal oxynitride thin film transistors and circuits

• US 20100301343A1
• Filed: 06/01/2009
• Published: 12/02/2010
• Est. Priority Date: 06/01/2009
• Status: Active Grant

• Current Assignee: Chunong Qiu, Cindy X. Qiu, Ishiang Shih, Yi-Chi Shih
• Original Assignee: Chunong Qiu, Cindy X. Qiu, Ishiang Shih, Yi-Chi Shih
• Inventors: Qiu, Cindy X., Shih, Yi-Chi, Qiu, Chunong, Shih, Ishiang
• Granted Patent: US 8,314,421 B2
• Time in Patent Office: Days
• US Class Current: 257/66
• 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

Thin film transistors and circuits having improved mobility and stability are disclosed in this invention to have metal oxynitrides as the active channel layers. In one embodiment, the charge carrier mobility in the thin film transistors is increased by using the metal oxynitrides as the active channel layers. In another embodiment, a thin film transistor having a p-type metal oxynitride active channel layer and a thin film transistor having an n-type metal oxynitride active channel layer are fabricated to forming a CMOS circuit. In yet another embodiment, thin film transistor circuits having metal oxynitrides as the active channel layers are provided.

Claims

1. A metal oxynitride thin film transistor with improved charge carrier mobility:

a first substrate;

a first gate electrode;

a first gate insulating layer;

a source electrode;

a drain electrode; and

a first metal oxynitride channel layer.

2. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein said first substrate is selected from a group comprising:

glass substrate, silica substrates, plastic sheets, metallic sheet with dielectric coating, ceramic substrates and semiconducting substrates with dielectric coating.

3. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein material of said metal oxynitride is selected from a group comprising:

indium oxynitride, zinc oxynitride, tin oxynitride, gallium oxynitride, titanium oxynitride, germanium oxynitride, silicon oxynitride and their mixtures.

4. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein said first metal oxynitride active channel layer is formed by a method comprising:

thermal evaporation, reactive evaporation, sputtering, reactive sputtering, CVD, and PECVD.

5. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein said charge carrier mobility of said metal oxynitride is controlled by metal content and nitrogen to oxygen ratio in said first metal oxynitride channel layer.

6. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein said charge carrier mobility of said metal oxynitride is further controlled by deposition conditions and post thermal treatment of said first metal oxynitride channel layer.

7. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein conducting type of said metal oxynitride is controlled by adjusting metal content and nitrogen to oxygen ratio in said first metal oxynitride channel layer.

8. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, wherein said first gate insulator is a material selected from a group of silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, hafnium oxide, strontium titanate, and their combinations.

9. A metal oxynitride thin film transistor with improved charge carrier mobility as defined in claim 1, further comprising a passivation layer for protection of said first metal oxynitride active channel.

10. A CMOS circuit with improved charge carrier mobility comprising:

a first p-channel metal oxynitride thin film transistor having a p-type metal oxynitride channel layer, a first gate electrode, a first gate insulator, a first source electrode, and a first drain electrode, and

a second n-channel metal oxynitride thin film transistor having a n-type metal oxynitride channel layer, a second gate electrode, a second gate insulator, a second source electrode, and a second drain electrode,

wherein said first gate electrode is connected to said second gate electrode and first drain electrode is connected to said second drain electrode.

11. A CMOS circuit with improved charge carrier mobility as defined in claim 10, wherein material of said p-type and n-type metal oxynitride is selected from a group comprising:

indium oxynitride, zinc oxynitride, tin oxynitride, gallium oxynitride, titanium oxynitride, germanium oxynitride, silicon oxynitride and their mixtures.

12. A CMOS circuit with improved charge carrier mobility as defined in claim 10, wherein conducting type of said p-channel and n-channel is controlled by controlling metal content and oxygen to nitrogen ratio of said metal oxynitride channel layer.

13. A CMOS circuit with improved charge carrier mobility as defined in claim 10, further comprising a first passivation layer for protection of said first p-type metal oxynitride active channel and a second passivation layer for protection of said second n-type metal oxynitride active channel.

14. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility comprising:

a plurality of thin film transistors, each with a metal oxynitride active channel layer.

15. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility as defined in claim 14, wherein material of said metal oxynitride is selected from a group comprising:

indium oxynitride, zinc oxynitride, tin oxynitride, gallium oxynitride, titanium oxynitride, germanium oxynitride, silicon oxynitride and their mixtures.

16. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility as defined in claim 14, where conducting type of each said metal oxynitride active channel layer of said thin film transistors is controlled by controlling metal content and oxygen to nitrogen ratio of said each metal oxynitride channel layer.

17. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility as defined in claim 14, said circuit is for optical sensor.

18. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility as defined in claim 14, said circuit is for rf identification tag applications.

19. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility as defined in claim 14, said circuit is for microwave applications.

20. A circuit of metal oxynitride thin film transistors with improved charge carrier mobility as defined in claim 14, said circuit is for electronic displays.