Mechanical characterization of sub-micrometer thick DLC films by AFM tensile testing for surface modification in MEMS

Abstract

This paper describes mechanical properties of Diamond-like Carbon (DLC) films for the protection of MEMS against their friction and wear. The compact tensile tester operated in atomic force microscope (AFM) was developed in this research to evaluate Young's modulus, Poisson's ratio and fracture strength of DLC films. Single crystal silicon (SCS) and DLC coated SCS (DLC/SCS) specimens on a micrometer scale were used in the tests. The DLC films with thickness of 0.2 and 0.3 /spl mu/m were deposited on 20 /spl mu/m-thick SCS specimens by Plasma-enhanced Chemical Vapor Deposition (PE-CVD) method of the hot cathode Penning Ionization Gauge (PIG) discharge type. The AFM tensile test and nano-indentation test were revealed that Young's modulus and Poisson's ratio of the DLC films ranged from 99 GPa to 112 GPa, and from 0.36 to 0.46, respectively.