The Effect of RF Substrate Biasing on the Properties and Structure of DLC Films by ECR - PECVD
강대환Dae Hwan Kang, 김기범Ki Bum Kim, 김태호Tae Ho Kim, 이지화Ji Wha Lee
Abstract
DLC(Diamond-Like Carbon) films were deposited using a CH₄-Ar ECR plasma on either Si or slide glass substrates. RF bias was applied to substrate to study the effects of the ion bombardment energy on the structure and properties of the deposited film. We identified that the hard carbon films were obtained above 40V bias. The transition of the as-deposited film from soft polymer-like to hard diamond-like was identified by using Knoops microhardness test, Ellipsometry, Roman and FT-IR spectroscopy. The plasma potential of about 20V were measured at a place close to the substrate to be independent of the rf bias by inserting single langmuir probe into CH₄-Ar ECR plasma. The impacting ion energy was thus calculated by summing the ion energy at bulk plasma and the accelerating energy in sheath due to the plasma potential and rf negative bias. From this we can conclude that the impacting ion energy higher than 60 eV is required to obtain hard diamond-like carbon films.