Micro-machine fabrication using diamond-like carbon films

Abstract

In this work we use diamond-like carbon (DLC) films deposited by a RF magnetron sputtering system in micro-electro mechanical systems (MEMS) development. The principal applications of DLC films in MEMS application are micro-channels for microfluidric devices, mechanical micro-machines, micro-optical devices, and mechanical actuators. These films were produced by a reactive RF magnetron sputtering system from a target of carbon in a stable graphite allotropic form with purity of 99.9999% and methane plasma. The DLC films were deposited on silicon substrates. The deposition rate was 2.5 nm/min and the films showed low mechanical stress. The films were patterned by a lithography step and the structures were obtained by a reactive ion etching using oxygen plasma. The etching rate in this process was 1 μm/min. The film thickness was measured with a height step meter and a ellipsometer. Fourier transform infrared (FTIR) and Raman spectroscopy were used to identify the sp 2 and sp 3 hybridization of C, CH bonds and other possible bonds that can appear; atomic force microscopy (AFM), was used to measure film roughness.