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The high-temperature stability of a Pt/TaSi2/Ni/SiC ohmic contact metallization scheme was characterized using a combination of current-voltage measurements, Auger electron spectroscopy, and transmission electron microscopy imaging and associated analytical techniques. Increasing the thicknesses of the Pt and TaSi2 layers promoted electrical stability of the contacts, which remained ohmic at 600A degrees C in air for the extent of heat treatment; the specific contact resistance showed only a gradual increase from an initial value of 5.2 x 10(-5) Omega cm(2). We observed a continuous silicon oxide layer in the thinner contact structures, which failed after 36 h of heating. Meanwhile, thicker contacts with enhanced stability contained a much lower oxygen concentration that was distributed across the contact layers, precluding the formation of an electrically insulating contact structure. The original publication is available at www.springerlink.com:Ariel Virshup, Fang Liu, Dorothy Lukco, Kristina Buchholt, Anita Lloyd Spetz and Lisa M Porter, Improved Thermal Stability Observed in Ni-Based Ohmic Contacts to n-Type SiC for High-Temperature Applications, 2011, JOURNAL OF ELECTRONIC MATERIALS, (40), 4, 400-405.http://dx.doi.org/10.1007/s11664-010-1449-0Copyright: Springer Science Business Mediahttp://www.springerlink.com/

Silicon carbide (SiC) is one of the major components of cosmic dust. Small silicon carbide dust particles show a prominent lattice vibrational band at ~11.3 m m. In the 1960s, Friedemann et al. (1969) first predicted that SiC condenses in carbon-rich stellar ejecta. Later, SiC was detected in the circumstellar envelopes around evolved C stars through the 11.3 m m spectral feature. The existence of SiC in the interstellar medium (ISM) was established through the detection of presolar SiC grains in primitive meteorites based on the isotopic anomaly. However, the 11.3 m m absorption feature of SiC is surprisingly not seen in the ISM. This work mainly introduces the optical properties of silicon carbide, the observed characteristics of silicon carbon in a series of astrophysical environment, and abundance of silicon carbide in interstellar space and the underlying physics.

Microfabricated thermionic emitters form a crucial part of thermionic energy converters, which could find applications in future concentrated solar thermal power plants. Here we report a new stress-relieved design for p-doped and n-doped silicon carbide (SiC) emitters, measurements of their thermionic emission and work functions at temperatures of up to 2900K, and the effect of optical irradiation on both types of SiC emitters. We also report the first observation of the photon-enhanced thermionic emission (PETE) in a thin-film microfabricated emitter.

Owing to the high power density, long life time and environmentally friendly characteristics, micro-supercapacitors have attracted much attention for powering microelectromechanical systems (MEMS) devices. This paper describes the fabrication and performance of a planar micro-supercapacitor. The fabrication process is large scale and IC compatible, and thus it can be integrated with microelectronics. The device, made of high conductivity graphitic carbon (GC) on nitrogen-doped polycrystalline 3C-SiC (poly-SiC), has very high charge/discharge rates. The incorporated nitrogen in the carbon electrode induces pseudo-capacitance and realizes nearly twice the specific capacitance value reported on carbon nanotube (CNT) supercapacitors.

Electrical contact to silicon carbide with low contact resistivity and high stability is a critical requirement for SiC-based microsystem and nanosystem technology for harsh environment applications. In this letter, nanocrystalline graphitic carbon is grown at the interface between SiC and Pt to lower the Ohmic contact resistivity and enhance the stability of Pt contacts to polycrystalline 3C-SiC operated at elevated temperatures. Analysis shows that reduced barrier height, oxide-free surface, reduced density of vacancy defects, and suppressed reactivity between Pt and SiC are likely responsible for the reduced Ohmic contact resistivity and high thermal stability of Pt contacts to graphitized SiC.

In this paper, we provide the first report of corrosion occurring at the anode of polycrystalline 3C-silicon carbide MEMS electrodes under high relative humidity and applied voltage. This unusual phenomenon is determined to be electrochemical in nature. Electrode pair and canary wire corrosion behavior are investigated to yield a detailed evaluation of the stability and oxidation rate during corrosion. The effects of film stress on anodic oxidation are discussed, and suggestions to prevent damage due to corrosion are presented.