Investigation in the effect of nitrogen incorporation in heteroepitaxial diamond film growth, texture, morphology, and crystalline quality

Summary form only given. It has been shown that even small concentrations of nitrogen have a substantial effect on the growth of CVD diamond films, while larger concentrations may result in degraded and rough growth. In the present study we show the effect of nitrogen concentration on the growth, texture, morphology, and crystalline quality of CVD diamond films. All films are heteroepitaxially grown on a 3 inch silicon substrate and are scratch-seeded with a seeding density of 10/sup 9//cm/sup 2/. A computer controlled 5 inch discharge 2.45GHz microwave plasma reactor with ultra-high vacuum gas handling systems combined with optical emission spectroscopy allows exact control of the gas phase concentrations and reactor input variables. Nitrogen gas phase concentration is varied from l0ppm to over 1000ppm and is controlled by the measurement of CN bands in the optical emission spectrum of the plasma. Pressure ranges from 38-50 Torr, methane/hydrogen from 0.5-2%, and flow rate from 50-200 sccm. Growth and morphology are carefully determined using SEM while texture is obtained using XRD. Crystalline quality is measured by determining the FWHM of the diamond Raman peak at 1332/cm using unpolarized micro-Raman spectroscopy. Detailed growth, texture, morphology, and crystalline quality maps are given to show the sequential effect of increasing nitrogen versus all other reactor input variables.