Effect of rapid thermal annealing on the electrical characteristics of ZnO thin-film transistors

Kariyadan Remashan, Dae Kue Hwang, Seong Ju Park, Jae Hyung Jang

Research output: Contribution to journalArticlepeer-review

27 Scopus citations

Abstract

Thin-film transistors (TFTs) with a bottom-gate configuration were fabricated with an RF magnetron sputtered undoped zinc oxide (ZnO) channel layer and plasma-enhanced chemical vapor deposition (PECVD) grown silicon nitride as a gate dielectric. Postfabrication rapid thermal annealing (RTA) and subsequent nitrous oxide (N2O) plasma treatment were employed to improve the performance of ZnO TFTs in terms of on-current and on/off current ratio. The RTA treatment increases the on-current of the TFT significantly, but it also increases its off-current. The off-current of 2 × 10-8 A and on/off current ratio of 3 × 103 obtained after the RTA treatment were improved to 10-10 A and 105, respectively, by the subsequent N2O plasma treatment. The better device performance can be attributed to the reduction of oxygen vacancies at the top region of the channel due to oxygen incorporation from the N2O plasma. X-ray photoelectron spectroscopy (XPS) analysis of the TFT samples showed that the RTA-treated ZnO surface has more oxygen vacancies than as-deposited samples, which results in the increased drain current. The XPS study also showed that the subsequent N2O plasma treatment reduces oxygen vacancies only at the surface of ZnO so that the better off-current and on/off current ratio can be obtained.

Original languageEnglish
Pages (from-to)2848-2853
Number of pages6
JournalJapanese Journal of Applied Physics
Volume47
Issue number4 PART 2
DOIs
StatePublished - 25 Apr 2008

Keywords

  • N plasma
  • NO plasma
  • Rapid thermal annealing
  • Thin-film transistor
  • ZnO

Fingerprint

Dive into the research topics of 'Effect of rapid thermal annealing on the electrical characteristics of ZnO thin-film transistors'. Together they form a unique fingerprint.

Cite this