| AVS 60th International Symposium and Exhibition | |
| Electronic Materials and Processing | Thursday Sessions |
| Session EM-ThP |
| Session: | Electronic Materials and Processing Poster Session |
| Presenter: | Y. An, Sungkyunkwan University, Republic of Korea |
| Authors: | Y. An, Sungkyunkwan University, Republic of Korea Y.-C. Byun, Sungkyunkwan University, Republic of Korea S. Choi, Sungkyunkwan University, Republic of Korea H. Kim, Sungkyunkwan University, Republic of Korea |
| Correspondent: | Click to Email |
For the development of high speed III-V-based metal-oxide-semiconductor field-effect transistors (MOSFETs) in replacement of current Si-based devices, high-k gate dielectric is the most crucial component and, especially, atomic layer deposition (ALD) technique has been acknowledged to be the ultimate solution in acquiring high electrical quality such as low leakage current and equivalent oxide thickness (EOT). In order to achieve a sub-1nm EOT value, many researchers have tried to introduce TiO2 film due to its much higher k value than Al2O3 and HfO2 [1, 2]. However, one major drawback in adopting TiO2 is relatively high leakage current due to its small band gap (~3.1 eV) [1]. As an effort to reduce the leakage current, recently, Kim et al. employed Al-doped TiO2 (ATO) films for memory capacitor application and demonstrated promising electrical performance [1]. More recently, Mahata et al. tried (TiO2)x(Al2O3)1-x alloy film on In0.53Ga0.47As as a gate insulator [2].
In this study, we deposited various ATO films on S-passivated p-type GaAs substrates and characterized their electrical properties, while varying the Al2O3 doping concentration and film thickness. The nanolaminating ALD process for the formation of ATO films utilized trimethylaluminum, titanium tetrakis-isopropoxide, and H2O precursors at a deposition temperature of 250 °C. After MOS capacitor fabrication, various electrical properties including capacitance-voltage, interface state density, and leakage current were evaluated. The dependency of these electrical properties on the ATO film composition will be discussed and correlated with various interface and film characterization results.
[1] S. K. Kim, G.-J. Choi, S. Y. Lee, M. Seo, S. W. Lee, J. H. Han, H.-S. Ahn, S. Han, and C. S. Hwang, Adv. Mater. 20, 1429 (2008).
[2] C. Mahata, S. Mallik, T. Das, C. K. Maiti, G. K. Dalapati, C. C. Tan, C. K. Chia, H. Gao, M. K. Kumar, S. Y. Chiam, H. R. Tan, H. L. Seng, D. Z. Chi, and E. Miranda, Appl. Phys. Lett. 100, 062905 (2012).