Single crystalline diamond grown by repositioning substrate in DC arcjet plasma enhanced chemical vapor deposition

DC arcjet plasma was diagnosed by spatial resolution optical emission spectra (OES). A flexible sample holder was thus constructed to avoid the fluctuation of gas phase species. By this flexible sample holder, single crystalline diamonds were grown on natural diamond substrates without the poly-crystallization. The influence of growth parameters, the total feed gases flow and the substrate movement velocity, on the morphology of the growth surface was studied by the scan electron microscope (SEM). Growth steps and hillocks were observed on as-grown surfaces. There existed compressive stresses in growth surfaces detected by Raman spectra, from which the occurrence of the hillock was thought to be ascribed to the development of Asaro–Tiller–Grinfeld (ATG) type morphology instability.

DC arcjet plasma was diagnosed by spatial resolution optical emission spectra. The fluctuation of gas phase species was found. A flexible sample holder was thus, constructed to avoid the fluctuation of the gas phase species. The single crystal diamond was continuously grown in this sample holder without the poly-crystallization. The repositioning velocity of the substrate was found to influence the morphology of as-grown diamond. The hillock growth was ascribed to the development of ATG type morphology instability caused by the compressive stress.Figure optionsDownload as PowerPoint slideHighlights
► C2 radical optical emission intensity was spatially detected under the condition of different feed gases flow.
► A flexible sample holder was constructed to avoid the fluctuation of the nutrition radical in arcjet plasma.
► Single crystal diamond was continuously grown without the poly-crystallization.
► The movement velocity of the substrate influenced the morphology of the as-grown diamond.
► The hillock growth was thought to be ascribed to the development of the ATG type morphology instability.