Fabrication and Characterization of 4H-SiC MOSFET with MOCVD-Grown Al2O3 Gate Insulator


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We have fabricated and characterized MOS capacitors and lateral MOSFETs using Al2O3 as a gate insulator. Al2O3 films were deposited by metal-organic chemical vapor deposition (MOCVD) at temperatures as low as 190 oC using tri-ethyl-aluminum and H2O as precursors. We first demonstrate from the capacitance – voltage (C-V) measurements that the Al2O3/SiC interface has lower interface state density than the thermally-grown SiO2/SiC interface. No significant difference was observed between X-ray photoelectron spectroscopy (XPS) Si 2p spectrum from the Al2O3/SiC interface and that from the SiC substrate, which means the SiC substrate was not oxidized during the Al2O3 deposition. Next, we show that the fabricated lateral SiC-MOSFETs with Al2O3 gate insulator have good drain current – drain voltage (ID-VD) and drain current – gate voltage (ID-VG) characteristics with normally-off behavior. The obtained peak values of field-effect mobility (μFE) are between 68 and 88 cm2/Vs.



Materials Science Forum (Volumes 556-557)

Edited by:

N. Wright, C.M. Johnson, K. Vassilevski, I. Nikitina and A. Horsfall




S. Hino et al., "Fabrication and Characterization of 4H-SiC MOSFET with MOCVD-Grown Al2O3 Gate Insulator ", Materials Science Forum, Vols. 556-557, pp. 787-790, 2007

Online since:

September 2007




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[4] S. Hino, T. Hatayama, N. Miura, T. Ozeki and E. Tokumitsu: International Conference on Silicon Carbide and Related Materials (ICSCRM 2005), Pittsburgh, 2005 Fig. 4. ID - VD characteristic of Al2O3/SiC MOSFET. Fig. 5. ID - VG and µFE - VG characteristics of Al2O3/SiC MOSFET.

2 4 6 8 10.

0. 5.

[1] 1. 5 Drain Voltage (V) Drain Current (mA) VG = 9V VG = 8V VG = 7V VG = 6V VG = 5V VG = 4V VG = 3V VG = 0-2 V.

DOI: https://doi.org/10.1515/9783110912067.420

1 2 3.

[10] [20] [0] [20] [40] [60] [80] Gate Voltage (V) Drain Current (µA) Field Effect Mobility (cm2/Vs) L/W=10/100µm VD=0. 1V.