Certification of diamond HPHT-plates for their use as substrates for CVD-synthesis

Abstract

Incoming control of substates and gases is very important part of technological chain. The properties of diamond layer on substrates with different misorientation angles may differ considerably, therefore, determining the deviation of diamond growth plane (100) from the direction [100] is important. Also, in order to select diamond substrates that are most suitable for synthesis of pure quality crystal, it is required to determine the content of impurities in them and the roughness of their surface. In this research, HPHT-plates of one lot were examined using Fourier transform infrared spectrometry, high-resolution diffractometry and scanning probe microscopy in order to classify them according to the studied parameters. Further the classified diamond substrates were used to synthesize diamond layers. Ardis 300 was used for deposition of monocrystalline diamond; synthesis was carried out from a methane-hydrogen plasma with 3% methane at a temperature of 1100 °C, a pressure of 26.7 kPa and a power of 3800 W. The studies have shown that certification of diamond HPHT-plates allows to select substrates for the synthesis of pure quality monocrystalline diamonds.