High temperature line electrode assembly for continuous substrate flow VHF PECVD

Abstract Plasma enhanced chemical vapour deposition is a preferred deposition technique for various thin films with high deposition rates. The increase of the excitation frequency and the substrate area in a fixed substrate processing mode is limited by the film non-uniformity due to standing waves, high process gas consumption and expensive substrate handling technology. To overcome these limitations VHF line electrode assemblies for a continuous substrate flow processing can be used. The active electrode area in one spatial dimension is reduced by moving the substrate perpendicular to the larger electrode dimensions. To meet the requirements of continuous substrate flow VHF PECVD processes at higher substrate temperature, a new high temperature VHF line electrode assembly VEA 750 HT was developed. The line electrode dimensions are 750 × 250 mm. It can be operated at substrate temperatures of up to 500 °C and with an excitation frequency of 40.68 or 81.36 MHz. The operating pressure was in the range of 5–10 Pa. The line electrode was tested in a laboratory type a-SiN x :H ARC PECVD system. High deposition rates up to 1 nm/s with film thickness variations of less than 3% have been achieved. Process chamber cleaning under vacuum conditions was carried out by a dry plasma etching process.