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The chemical and microstructural characteristics of silicon carbide films deposited on 100 mm diam, silicon ͑100͒ wafers in a large-volume, low-pressure chemical vapor deposition ͑LPCVD͒ furnace using dichlorosilane (SiH 2 Cl 2 ) and acetylene (C 2 H 2 ) were investigated. The deposition temperature was held constant at 900°C and the pressure ranged between 460 and 510 mTorr. X-ray photoelectron spectroscopy data indicated that stoichiometric SiC was deposited using SiH 2 Cl 2 -to-C 2 H 2 molar ratios of 4:1, 6:1, and 8:1. X-ray diffraction showed that the stoichiometric films were highly textured, 3C-SiC͑111͒ at all locations across each wafer. These findings indicate that the SiH 2 Cl 2 /C 2 H 2 precursor system has great potential for use in large-scale LPCVD furnaces and produces SiC films with a microstructure that has advantageous properties for use in high-frequency resonator micromechanical devices.SiC is well known for its excellent properties, making it an outstanding addition to the microelectromechanical systems ͑MEMS͒ technology toolbox. Increasing interest in SiC for coating and structural device applications, combined with recent demonstrations of SiC surface micromachining processes, 1,2 have provided substantial impetus for developing deposition and process technologies similar to those for polysilicon; films that are typically deposited on largearea silicon wafers in large horizontal low-pressure chemical vapor deposition ͑LPCVD͒ furnaces. This paper reports the development of recipes for the deposition of polycrystalline SiC ͑poly-SiC͒ films in a high-throughput, LPCVD furnace on large-area substrates at 900°C. This technology is being developed to support a multilayer SiC surface micromachining process named MUSiC™ ͑for MultiUser SiC͒. 3 The MUSiC process is a four-layer poly-SiC process that generally embodies the design rules and capabilities of the now well established Cronos Integrated Microsystems polysilicon MUMPs™ process.While a few LPCVD processes have been reported for deposition of poly-SiC in recent years, 4-8 it appears that these processes were performed in research-sized chambers too small in volume to meet the batch processing needs required of commercially viable technologies. Nevertheless, the successes reported in these early studies provide sufficient motivation to develop similar large-scale LPCVD systems for the deposition of SiC.Silicon carbide films were deposited on 100 mm diam silicon ͑100͒ wafers in a conventional, hot-wall horizontal furnace using SiH 2 Cl 2 and C 2 H 2 as silicon and carbon-containing precursors. The furnace tube was large by SiC deposition standards, measuring 2007 mm in length and 225 mm in diameter. Although the furnace is capable of holding up to 100 wafers, each load consisted of 10 wafers held in a single, 50 slot quartz boat, with the first three and last three slots in the boat filled with wafers, and the other four wafers evenly distributed throughout the remaining slots. Prior to loading the furnaces, all wafers were cleaned using a stand...

Abslracf -Silicon carbide (SIC) is an excellent candidate for use in next generation RF MEMS devices such as microfabricated switches, micromechanical resonators, and filters. SIC is characterized ,by a wide bandgap, high acoustic velocity, high thermal conductivity, high electrical breakdown strength, and low chemical reactivity. These material properties lead to potential improvements in operating frequency, power handling capability, and reliability for such devices relative to their silicon counterparts.Furthermore, film deposition and micromachining techniques for Sic have been developed which leverage established tools and processes found in silicon-based microfahrication facilities, thereby demonstrating Sic as a commercially viable microsystem material. This paper will present recent performance results from Sic-based RF MEMS components.

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X-ray lithography is a very good option for the fabrication of micro-devices especially when high aspect ratio patterns are required. Membrane-based x-ray masks are commonly used for high-resolution x-ray lithography. A thin layer of silicon nitride (Si 3 N 4 ) or silicon carbide (SiC) film (1-2 µm) is normally used as the membrane material for x-ray mask fabrication (Wells