Surface observation of P-Sic substrate after negative bias treatment in diamond deposition

Recently, high oriented texture growth of diamond thin films on P-Sic has been obtained by the bias-enhanced-nucleation (BEN) method in a microwave plasma-assisted chemical vapor deposition (MPCVD) system. Negative bias treatment, as process of nucleating diamond, is an important process. However, there are a lot of unknown matters in the nucleation process of diamond. We here focused our attention on the interface between (100) P-Sic substrate and grown diamond film. In this study, we exposed P-Sic substrates to (HZ + CH,) plasma during the negative bias application, and found that the P-Sic layer is markedly etched off during this treatment. Nevertheless, once the amorphous ultra-thin layer was formed by a carbonization procedure in advance, there was no sign of P-Sic etching even for negative bias treatment, and moreover this significantly enhances nucleation of diamond on it. In addition, we demonstrated the effect of xenon additive to (H, + CH,) plasma, which increased the deposition rate of diamond films. This might promise mild diamond growth and save the interface from the plasma damage.