Diamond-like carbon for MEMS

• Published in: Journal of micromechanics and microengineering 2007-07, Vol.17 (7), p.S83-S90
• Main Authors: Peiner, Erwin, Tibrewala, Arti, Bandorf, Ralf, Lüthje, Holger, Doering, Lutz, Limmer, Wolfgang
• Format: Article
• Language: English
• Subjects: Applied sciences; Electronics; Exact sciences and technology; General equipment and techniques; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Mechanical engineering. Machine design; Mechanical instruments, equipment and techniques; Microelectronic fabrication (materials and surfaces technology); Micromechanical devices and systems; Physics; Precision engineering, watch making; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Transducers
• ISSN: 0960-1317; 1361-6439
• DOI: 10.1088/0960-1317/17/7/S04

Sputter-deposited amorphous diamond-like carbon (DLC, a-C) on silicon has been investigated with respect to micro electro mechanical systems (MEMS) applications. Sputtered a-C with a content of diamond-like sp3 bonded carbon of around 25% showed a high hardness of up to 30 GPa. Self-supporting cantilevers of 0.5 mum in thickness, several hundreds of mum in length and some tens of mum in width have been successfully realized using lift-off patterning of DLC and anisotropic silicon etching. The mechanical properties of DLC (Young's modulus, stress, stress gradient fracture strength) were characterized by cantilever deflection analyses. DLC strain gauge resistors integrated on micromachined silicon boss membranes were investigated under tensile and compressive loading. Piezoresistive gauge factors in the range of 20-30 were observed at temperatures between room temperature and 50 deg C.