Surface micromachining of polycrystalline SiC films using microfabricated molds of SiO2 and polysilicon

As an alternative to conventional SiC reactive ion etching (RIE), polycryst alline (poly-SiC) films were patterned into micron-sized structures using s acrificial SiO2 and polycrystalline silicon (polysilicon) molds in conjunct ion with mechanical polishing. The molds were made from thermally grown SiO 2 and LPCVD polysilicon films and were fabricated using conventional patter ning techniques. The poly-SiC micromolding process combines film deposition , polishing, and selective wet chemical etching of the molds to achieve the desired pattern. The process is simple and does not suffer from the diffic ulties associated with RIE of SiC. Micrometer-sized lines, spaces, and comp lex device structures have been patterned using this technique. The micromo lding technique has been used in a SiC surface micromachining process to fa bricate fully released lateral resonant structures.