Electron cyclotron resonance (ECR) plasma was applied to enhance the direct cur- rent magnetron sputtering to prepare hydrogenated diamond-like carbon (H-DLC) ¯lms. Fordi®erent microwave powers, both argon and hydrogen gas are introduced separately as the ECR working gas to investigate the in°uence of microwave power on the microstructure and electricalproperty of the H-DLC ¯lms deposited on P-type silicon substrates. A series of characterization methods including the Raman spectrum and atomic force microscopy are used. Results show that,within a certain range, the increase in microwave power a®ects the properties of the thin ¯lms, namely the sp3 ratio, the hardness, the nanoparticle size and the resistivity all increase while the roughness decreases with the increase in microwave power. The maximum of resistivity amounts to 1.1£109 ­¢ cm. At the same time it is found that the in°uence of microwave power on the
properties of H-DLC ¯lms is more pronounced when argon gas is applied as the ECR working gas, compared to hydrogen gas.