Abstract
This study reports the performance and stability of hafnium-indium zinc oxide (HfInZnO) thin film transistors (TFTs) with thermally grown SiO2. The HfInZnO channel layer was deposited at room temperature by a co-sputtering system. We examined the effects of hafnium addition on the X-ray photoelectron spectroscopy properties and on the electrical characteristics of the TFTs varying the concentration of the added hafnium. We found that the transistor on-off currents were greatly influenced by the composition of hafnium addition, which suppressed the formation of oxygen vacancies. The field-effect mobility of optimized HfInZnO TFT was 1.34 cm2 V-1 s-1, along with an on-off current ratio of 108 and a threshold voltage of 4.54 V. We also investigated the effects of bias stress on HfInZnO TFTs with passivated and non-passivated layers. The threshold voltage change in the passivated device after positive gate bias stress was lower than that in the non-passivated device. This result indicates that HfInZnO TFTs are sensitive to the ambient conditions of the back surface.
| Original language | English |
|---|---|
| Pages (from-to) | 6815-6819 |
| Number of pages | 5 |
| Journal | Thin Solid Films |
| Volume | 519 |
| Issue number | 20 |
| DOIs | |
| State | Published - 1 Aug 2011 |
Bibliographical note
Funding Information:This work was supported by MEST and DGIST . (Renewable Energy and Intelligent Robot Convergence Technology Development). We thank Dr. Bae of the Korea Basic Science Institute Busan Center for obtaining the XPS spectra.
Keywords
- HfInZnO
- High-k material
- Metal oxide thin film transistor