Conditioning of the filament for diamond deposition by hot-filament chemical vapour deposition method

摘要

A tungsten filament, 0.12 mm in diame- ter, was conditioned by heating in a mixture of methane and hydrogen of three different concen- tration ratios. The filament was heated by an electric current. The procedure was carried out stepwise keeping either the voltage or the tem- perature of the filament constant. Changes in the filament material were monitored by resistance and temperature measurements. The chemical composition was checked using X-ray diffraction (XRD) analysis. The final state of the filament was investigated and photographed using the scan- ning electron microscopy (SEM) technique.