SiC is an extremely promising material for nanoelectromechanical systems given its large Young's modulus and robust surface properties. We have patterned nanometer scale electromechanical resonators from single-crystal 3C-SiC layers grown epitaxially upon Si substrates. A surface nanomachining process is described that involves electron beam lithography followed by dry anisotropic and selective electron cyclotron resonance plasma etching steps. Measurements on a representative family of the resulting devices demonstrate that, for a given geometry, nanometer-scale SiC resonators are capable of yielding substantially higher frequencies than GaAs and Si resonators. Silicon carbide is an important semiconductor for high temperature electronics due to its large band gap, high breakdown field, and high thermal conductivity. Its excellent mechanical and chemical properties have also made this material a natural candidate for microsensor and microactuator applications in microelectromechanical systems ͑MEMS͒. Recently, there has been a great deal of interest in the fabrication and measurement of semiconductor devices with fundamental mechanical resonance frequencies reaching into the microwave bands. Among technological applications envisioned for these nanoelectromechanical systems ͑NEMS͒ are ultrafast, high-resolution actuators and sensors, and high frequency signal processing components and systems.2 From the point of view of fundamental science, NEMS also offer intriguing potential for accessing regimes of quantum phenomena and for sensing at the quantum limit.SiC is an excellent material for high frequency NEMS for two important reasons. First, the ratio of its Young's modulus, E, to mass density, , is significantly higher than for other semiconducting materials commonly used for electromechanical devices, e.g., Si and GaAs. Flexural mechanical resonance frequencies for beams directly depend upon the ratio ͱ (E/). The goal of attaining extremely high fundamental resonance frequencies in NEMS, while simultaneously preserving small force constants necessary for high sensitivity, requires pushing against the ultimate resolution limits of lithography and nanofabrication processes. SiC, given its larger ͱ (E/), yields devices that operate at significantly higher frequencies for a given geometry, than otherwise possible using conventional materials. Second, SiC possesses excellent chemical stability.3 This makes surface treatments an option for higher quality factors ͑Q factor͒ of resonance. It has been argued that for NEMS the Q factor is governed by surface defects and depends on the device surface-to-volume ratio.

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