Chemical vapor deposition of homoepitaxial diamond films



This paper presents a review of state-of-the-art reports of homoepitaxial diamond growth. Crystal growth and characterization methods that are commonly used for homoepitaxial diamond studies are first described briefly. Then, effects of each process parameter on the growth mode of homoepitaxial diamond are discussed. Methane concentration and substrate temperature were two dominant parameters that determine the growth rate and crystalline quality of diamond films, while conditions of diamond substrates including crystal orientation and pretreatments should be optimized for high-quality diamond deposition. Attempts to increase growth rate of homoepitaxial diamond films while keeping their crystalline quality are discussed in the later section. Increase of microwave power density for plasma-assisted chemical vapor deposition was found to be effective for the high-rate growth of diamond. Free-exciton recombination emission was intensively observed from homoepitaxial films grown at higher growth rate of 3.5 μm/h under the high power density condition. In addition, boron-doped samples grown under the high-power conditions showed high Hall mobility of 1620 cm2 V s−1 at room temperature. The plasma power density is thus one of the important parameters of diamond deposition from the viewpoint of electronic device application. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)