Hydrogen implantation combined with bonding enables the transfer of large scale, single crystal thin films. This process, known as Smart Cut™, is well-established for silicon in the fabrication of SOI stacks but remains challenging for diamond due to its rough and non-planar surface hindering bonding. To improve bonding energy, surface activation bonding was used which led to a successful transfer of diamond thin films onto silicon with nearly 90% surface yield. However, the post-fracture diamond film exhibited a pyramidal surface topology. This particular topology is characterized by Raman spectroscopy, Cathodoluminescence, Scanning Electron Microscopy, Transmission Electron Microscopy, Atomic Force Microscopy, and Laue microdiffraction, and results from the formation of dihydrogen pressurized microcracks. The deformation of the crack walls causes the formation of vertical graphite sheets on the film's surface and induce plastic deformation in the underlying silicon substrate without compromising the diamond film's crystallinity or the bonding. Additionally, we propose a post-fracture surface cleaning method to obtain an epi-ready diamond film and to enable the reuse of the donor substrate. • High transfer rate of diamond film onto Si substrate using the Smart Cut™ process • Characterization of pyramidal surface morphology on the transferred diamond film • Cleaning process to recover a monocrystalline diamond surface suitable for epitaxial growth
Chrétien et al. (Mon,) studied this question.