金屬(Al)/ 鋁酸鑭（LaAlO3）/矽(Si)薄膜電容器與場效電晶體之製作與電性分析

The Fabrication and Characterization of Metal (Al)-Oxide-Si Capacitors and Field-effect Transistors Using LaAlO3 Gate dielectric

尤聖文(Sheng-Wen You)

指導教授 ： 李雅明

國立清華大學/電機資訊學院/電子工程研究所/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00702

摘要

Lanthanum aluminate (LaAlO3) is considered as a potential candidate for high-K dielectric applications. LaAlO3 has high dielectric constant (13-27), large energy band gap (over 5eV), high thermal stability (up to 850°C), low leakage current density, large electron band offset. The structure of Al/LaAlO3/Si capacitors and transistors were fabricated successfully. The oxide films were deposited by rf-sputtering. The leakage current density was 4.36×10-3A/cm2 when the applied voltage was -1V. The measured dielectric constant was 13.4. The dominant electrical conduction mechanism of LaAlO3 thin film was Schottky emission mechanism at 450K. The electron barrier-height between Al/LaAlO3 interface and electron effective mass in the LaAlO3 film were about 0.94 eV and 0.07 m0, respectively. Secondary ion mass spectrometry (SIMS) and X-ray diffraction (XRD) were also used to examine the material properties of LaAlO3.
The electrical characteristics of N-channel metal-oxide-semiconductor field effect transistors were also measured. The interface trapped charge density, effective electron mobility and sub-threshold swing were 2.27x1012cm-2-eV, 210cm2/V-s and 82.8 mV/dec., respectively. The degradation mechanisms of effective electron channel mobility and the threshold voltage shift in LaAlO3-gated n-MOSFETs were studied by analyzing experimental data at various temperatures from 11 K to 450 K. The mechanisms that influence the electron mobility include coulomb scattering, phonon scattering, surface roughness scattering.

關鍵字

鋁酸鑭 ； 移動率衰退

並列摘要

無資料

並列關鍵字

Lanthanum aluminate ； mobility degradation

參考文獻

[1] H. S. Momose, M. Ono, T. Yoshitomi, T. Ohguro, S. Makamura, M. Saito, and H. Iwai, “1.5 nm direct-tunneling gate oxide Si MOSFET’s,” IEEE Trans. Electron Devices, vol. 43, pp. 1233-1241, 1996.

[2] Y. H. Wu, A. Chin, “Electrical Characteristics of High Quality La2O3 Gate Dielectric with Equivalent Oxide Thickness of 5 Ả,” IEEE Electron Device Lett., vol. 21, no. 7, pp.341-343, 2000.

[3] M. J. Kelly, D. B. Terry, “Properties of La-silicate high-K dielectric films formed by oxidation of La on silicon,” J. Appl. Phys., vol. 93, pp. 1691-1696, 2003.

[4] W. K. Chim, T. H. Ng, B. H. Koh, W. K. Choi, J. X. Zheng, C. H. Tung, and A. Y. Du, “Interfacial and bulk properties of zirconium oxide as a gate dielectric in metal-insulator-semiconductor structures and current transport mechanisms,” J. Appl. Phys., vol. 93, no. 8, pp. 4788-4793, 2003

[5] M. Koyama, K. Suguro, M. Yoshiki, Y. Kamimuta, M. Koike, M. Ohse, C. Hongo, and A. Nishiyama, “Thermally stable ultra-thin nitrogen incorporated Gate Dielectric Prepared by Low Temperature Oxidation of ZrN,” in IEDM Tech. Dig., pp. 459-462, 2001