1989 年 55 巻 1 号 p. 155-160
This paper is related to diamond synthesis from mixed methane and hydrogen gas by microwave plasma CVD. In this study, the effects of substrate surface states on nucleation are experimentally examined. Silicon wafers are finished by different procedures to get different surface states. These procedures are grinding with diamond wheels, polishing with alumina, polishing with diamonds, mechano-chemical polishing with zirconia, blusting with glass bead and etching with mixed acid. In order to estimate nucleation density synthesizing are carried out for 2 hours under the condition of 1% methane concentration. Results obtained are as follows : The nucleation density of crystallographically damaged surfaces is higher than that of non-damaged surfaces. As undulations of the substrate surface affect on the flow of mixed gas, the nucleation density highly depends on the surface roughness.