| 摘要 |
PURPOSE:To obtain a ZnS film not causing cracking, having high adhesive strength to an optical substrate and hard to scratch by forming a thin ZnS film on the surface of the optical substrate while irradiating the substrate with electron beams. CONSTITUTION:An Si substrate as an optical substrate transmitting IR is held by a substrate holder 3 so that it, confronts an evaporating source 2 and an electron gun 4 in a vacuum deposition vessel 1. This vessel 1 is evacuated and a ZnS film is formed on the unheated substrate fitted to the holder 3 in a prescribed optical thickness by depositing ZnS evaporated from the evaporating source 2 on the substrate at the prescribed rate of deposition while irradiating the substrate with electron beams from the electron gun 4. Since ZnS is irradiated with electron beams during film formation, internal stress is relaxed like the case of ion beam assisted deposition, cracking is inhibited and adhesive strength is enhanced. |
