3C-SiC hetero-epitaxial films for sensor fabrication R. Anzalone 1,2,a , A. Severino 1,2,b , C. Locke 3c ,D. Rodilosso 4d , C. Tringali 4e S. E. Saddow 3f , F. La Via 1g and G. D’Arrigo 1h 1 IMM-CNR, sezione di Catania, Stradale Primosole 50, 95121, Catania, Italy 2 University of Catania, Phys. Dept., via Santa Sofia 64, 95125, Catania, Italy 3 Dept. of Electrical Engineering, USF, 4202 E. Fowler Ave., Tampa, Florida 33620, USA 4 ST-Microelectronics, Stradale Primosole 50, 95121, Catania, Italy a ruggero.anzalone@imm.cnr.it, b andrea.severino@imm.cnr.it, c clocke@mail.usf.edu, d davide.rodilosso@st.com, e cristina.tringali@st.com, f saddow@ieee.org, g Francesco.lavia@imm.cnr.it, h Giuseppe.darrigo@imm.cnr.it Abstract Silicon Carbide (SiC) is a very promising material for the fabrication of a new category of sensors and devices, to be used in very hostile environments (high temperature, corrosive ambient, presence of radiation, etc.). The fabrication of SiC MEMS-based sensors requires new processes able to realize microstructures on bulk material or on the SiC surface. The hetero-epitaxial growth of 3C- SiC on silicon substrates allows one to overcome the traditional limitations of SiC micro- fabrication. This approach puts together the standard silicon bulk microfabrication methodologies with the robust mechanical properties of 3C-SiC. Using this approach we were able to fabricate SiC cantilevers for a new class of pressure sensor. The geometries studied were selected in order to study the internal residual stress of the SiC film. X-Ray Diffraction polar figure and Bragg- Brentano scan analysis were used to check to crystal structure and the orientations of the film. SEM analysis was performed to analyze the morphology of the released MEMS structures. Introduction Silicon is a dominant material for the fabrication of micro-electromechanical systems (MEMS); however, its mechanical properties begin to degrade at elevated temperatures (>350 °C), making it increasingly unsuitable for high-temperature applications [1]. In contrast, SiC is well known for its mechanical hardness, chemical inertness, high thermal conductivity, and electrical stability at temperatures well above 600 °C. These properties, in combination with its compatibility with silicon processing techniques, make SiC one of the leading materials for harsh environment MEMS. Most MEMS devices require a structural layer to be formed over a sacrificial „release‟ oxide layer. Such structures based on SiC have been demonstrated by using single crystal 3C-SiC films, which can be heteroepitaxially grown on silicon substrates [2]. Furthermore, the important property of 3C– SiC is that it can be grown on large diameter Si (silicon) substrates, but cubic 3C–SiC also possesses unique properties, such as high electron drift velocity, which is more suitable for high- frequency power devices [3]. Many efforts have been made to develop processes that produce good quality hetero-epitaxial 3C- SiC films. The heteroepitaxial growth of SiC on Si substrates using conventional CVD reactors has yielded high-quality thin films of 3C–SiC. In the present research, chemical vapour deposition (CVD) in the low pressure regime of 3C–SiC on silicon substrates was carried out, using silane (SiH 4 ), propane (C 3 H 8 ) and hydrogen (H 2 ) as the silicon supply, carbon supply and gas carrier, respectively. With this process it is possible to obtain good quality of 3C-SiC single crystal films in order to study the residual internal stress for MEMS applications. Advances in Science and Technology Vol. 54 (2008) pp 411-415 online at http://www.scientific.net © (2008) Trans Tech Publications, Switzerland Online available since 2008/Sep/02 All rights reserved. No part of contents of this paper may be reproduced or transmitted in any form or by any means without the written permission of the publisher: Trans Tech Publications Ltd, Switzerland, www.ttp.net. (ID: 88.39.221.61-03/09/08,12:57:11)