Analysis of Hump Characteristics in Thin-Film Transistors With ZnO Channels Deposited by Sputtering at Various Oxygen Partial Pressures

Author

Furuta, Mamoru ; Kamada, Yudai ; Kimura, Mutsumi ; Hiramatsu, Takahiro ; Matsuda, Tokiyoshi ; Furuta, Hiroshi ; Li, Chaoyang ; Fujita, Shizuo ; Hirao, Takashi

Author_Institution

Res. Inst. for Nanodevices, Kochi Univ. of Technol., Kochi, Japan

Volume

31

Issue

11

fYear

2010

Firstpage

1257

Lastpage

1259

Abstract

The electrical properties of thin-film transistors (TFTs) with ZnO channels which were deposited by radio-frequency magnetron sputtering at various oxygen partial pressures [p( O₂)] are investigated. A negative shift of the turn-on voltage with a “hump” was observed, and donorlike traps were generated at intermediate energy levels from the conduction band when the ZnO channel was deposited at p(O₂) below a critical pressure. Thermal desorption spectroscopy study revealed that the donorlike traps were generated when the ZnO film changed from O- to Zn-rich condition. The Zn-related native defects would be a possible origin of the donorlike traps generated at intermediate energy levels in the ZnO TFTs.

Keywords

sputter deposition; thin film transistors; zinc compounds; ZnO; electrical properties; hump characteristics; sputtering; thin-film transistors; various oxygen partial pressures; Energy states; Logic gates; Radio frequency; Sputtering; Thin film transistors; Zinc oxide; Hump characteristics; intrinsic defects; sputtering; thermal desorption spectroscopy (TDS); thin-film transistors (TFTs); trap density; zinc oxide;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2010.2068276

Filename

5582194