SiC Field Effect Transistors

Different types of SiC Field Effect Transistors, Metal Oxide Semiconductor Transistors (MOSFETs), Metal Semiconductor Field Effect Transistors (MESFETs), and Junction Field Effect Transistors (JFETs) compete for future applications in high temperature and harsh environment electronics. This Datareview details these various types of FETs, the structures used and the performances obtained. Interesting recent developments and potential applications, such as FET integrated circuits, a hybrid operational amplifier and an inverter circuit are also outlined. 

The first SiC MOSFETs were fabricated by Suzuki et al [1] in 3C-SiC. At the present time, SiC MOSFET research is carried out by several groups, including Cree Research [2-4] and Westinghouse [5]. Enhancement mode and depletion mode (3-SiC MOSFETs have been fabricated by Palmour et al [3]. Enhancement mode devices with 5 pm gate lengths had a maximum transconductance (gm) of 0.46 mS mm 1 at room temperature (see FIGURES 1 and 2). The devices were operational up to 823 K. 

FIGURE 1 Fabrication steps for an enhancement mode P-SiC MOSFET [3]. 

FIGURE 2 Current-voltage characteristics of enhancement mode P-SiC MOSFETs at room temperature and 

FIGURE 3 Cross-section of n-channel enhancement mode a-SiC MOSFET [6]. 

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SiC field effect transistors TABLE 1 Performance of SiC FETs. 

Epitaxial graphene on SiC field effect transistors as gas sensors... 

LED due to the direct bandgap of the Ill-nitrides. However, due to the lack of a native substrate for GaN, sapphire or SiC substrates were and are still used. The biggest use of semiconductor-grade SiC is still for LEDs, but now it serves the role as the substrate for the active GaN layer rather than both the substrate and the active layer. Today there are high-freqnency metal-semiconductor-field effect transistors (MES-EETs) offered commercially, as well as an emerging market for Schottky diodes made from SiC. We are still at the beginning of the SiC revolution, however, and the material s full potential has yet to be realized. 

Palmour, J. W., H. S. Kong, and R. F. Davis, Characterization of Device Parameters in High-Temperature Metal-Oxide-Semiconductor Field-Effect Transistors in fi-SiC Thin Films, J. of Applied Physics, Vol. 64, No. 4, August 15, 1988, pp. 2168-2177. 

The application of modem epitaxial techniques (see Chapter 8) has led to a rapid improvement in the material quality of SiC and made practical SiC devices a reality. The applications of SiC include high-temperature, high-power devices, microwave devices (both avalanche diodes and field effect transistors), and optoelectronic devices, such as photodiodes and light-emitting diodes which emit throughout the visible spectrum into the ultraviolet. 

Moon, J., Curtis, D., Hu, M., Wong, D., McGuire, C., Campbell, P, Jernigan, G., Tedesco, J., VanMil, B. and Myers-Ward, R. (2009), Epitaxial-graphene RF field-effect transistors on Si-face 6H-SiC substrates. Electron Device Letters, IEEE, 36,650-2. 

The continual development of the deposition of SiC thin films and of large diameter single crystal SiC wafers, the associated technologies of doping, etching and electrical contacts have culminated in a host of new solid state devices including field effect transistors capable of operation up to 650°C [275]. 

Luft W, Tsuo YS (1993) Hydrogenated amorphous sUicon aUoy deposition processes. Dekker, New York, NY Lundstrbm I (2001) SiC based field effect gas sensors for industrial appUcations. Phys Status SoUdi (a) 185(1) 15-25 Lundstrbm I, Shirvamavan MS, Svensson C (1975a) A hydrogen-sensitive MOS field-effect transistor. Appl Phys Lett... 

S Yoshida, H Daimon, M Yamanaka, E Sakuma, S Misawa, K End. Schottky-barrier field-effect transistors of 3C-SiC. J Appl Phys 60 2989, 1986. 

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