THE EFFECTS OF BORON DOPING ON RESIDUAL STRESS OF HFCVD DIAMOND FILM FOR MEMS APPLICATIONS

Abstract

In this study, the residual stress of boron-doped diamond (BDD) films is investigated as a function of boron doping level using X-ray diffraction (XRD) analysis. Boron doping level is controlled from 1000[Formula: see text]ppm to 9000[Formula: see text]ppm by dissolving trimethyl borate into acetone. BDD films are deposited on silicon wafers using a bias-enhanced hot filament chemical vapor deposition (BE-HFCVD) system. Residual stress calculated by [Formula: see text] method varies linearly from [Formula: see text]2.4[Formula: see text]GPa to [Formula: see text]1.1[Formula: see text]GPa with increasing boron doping level. On the BDD film of [Formula: see text]1.75[Formula: see text]GPa, free standing BDD cantilevers are fabricated by photolithography and ICP-RIE processes, then tested by laser Doppler vibrometer (LDV). A cantilever with resonant frequency of 183[Formula: see text]KHz and [Formula: see text] factor of 261 in the air is fabricated.