Chapter 9 - Heteroepitaxial Growth on cBN, Ni, and Other Substrates

Abstract

This chapter describes the growth of heteroepitaxial diamond particles and films on cubic boron nitride (cBN), Ni, Co, Cu, TiC, BeO, Ni3Si, graphite, sapphire, and Si. Cubic boron nitride (cBN) has a zinc blende-type crystal structure with a lattice constant of 3.615 Å, which is very close to that of diamond. According to RHEED measurements with the electron beam parallel to the {111} layer of cBN, a growth of diamond by DC plasma chemical vapor deposition (CVD) on cBN (lll) [150] using c=0.5%CH4/H2, Ts=900°C and P= 180Torr led to a result that a smooth { 111 } layer of diamond was epitaxially deposited in such a way that the [110] direction of diamond was parallel to that of cBN. On the other hand, diamond growth on cBN(100) studied using c=2%CH4/H2, Ts 950°C and P = 180 Torr by DC plasma CVD (152) seemed to be appropriate for (100) growth of diamond. Then, a more thorough study of diamond growth on cubooctahedral cBN crystals with diameters of about 500gin was undertaken by DC plasma CVD. The growth conditions were c ∼ 2%CH4/H2, Ts = 950–970 ∼ and P = 200 Torr. The chapter briefly describes the interface between diamond and Si substrate. The major issues that are discussed are whether an interface layer is present, and what are the interface material and its atomic structure.