A novel process-compatible fluorination technique with electrical characteristic improvements of poly-Si TFTs

Author

Wang, Shen-De ; Lo, Wei-Hsiang ; Chang, Tzu-Yun ; Lei, Tan-Fu

Author_Institution

Dept. of Electron. Eng., Nat. Chiao Tung Univ., Hsinchu, Taiwan

Volume

26

Issue

6

fYear

2005

fDate

6/1/2005 12:00:00 AM

Firstpage

372

Lastpage

374

Abstract

A process-compatible fluorine passivation technique of poly-Si thin-film transistors (TFTs) was demonstrated by employing a novel CF₄ plasma treatment. Introducing fluorine atoms into poly-Si films can effectively passivate the trap states near the SiO₂/poly-Si interface. With fluorine incorporation, the electrical characteristics of poly-Si TFTs can be significantly improved including a steeper subthreshold slope, smaller threshold voltage, lower leakage current, higher field-effect mobility, and better on/off current ratio. Furthermore, the CF₄ plasma treatment also improves the reliability of poly-Si TFTs with respect to hot-carrier stress, which is due to the formation of strong Si-F bonds.

Keywords

carbon compounds; hot carriers; passivation; plasma materials processing; semiconductor device reliability; silicon compounds; thin film transistors; CF₄; CF₄ plasma treatment; Si-F bonds; SiO₂-Si; SiO₂/poly-Si interface; TFT reliability; electrical characteristic improvements; fluorine atoms; hot-carrier stress; poly-Si TFT; poly-Si thin-film transistors; process-compatible fluorination technique; process-compatible fluorine passivation technique; trap state passivation; Annealing; Electric variables; Glass; Ion implantation; Passivation; Plasma applications; Plasma immersion ion implantation; Stress; Substrates; Thin film transistors; TFTs; fluorine; fluorine passivation; poly-Si; process-compatible; reliability;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2005.848095

Filename

1432903