@article{govindaraju_aleksov_li_okuzumi_wolter_collazo_prater_sitar_2006, title={Comparative study of textured diamond films by thermal conductivity measurements}, volume={85}, ISSN={["1432-0630"]}, DOI={10.1007/s00339-006-3697-7}, number={3}, journal={APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING}, author={Govindaraju, N. and Aleksov, A. and Li, X. and Okuzumi, F. and Wolter, S. D. and Collazo, R. and Prater, J. T. and Sitar, Z.}, year={2006}, month={Nov}, pages={331–335} }
 @article{yushin_aleksov_wolter_okuzumi_prater_sitar_2004, title={Wafer bonding of highly oriented diamond to silicon}, volume={13}, ISSN={["1879-0062"]}, DOI={10.1016/j.diamond.2004.04.007}, abstractNote={Polished, highly oriented diamond (HOD) with an RMS roughness of less than 3 nm was bonded to single-side polished silicon wafers in ultra-high vacuum (UHV) at 32 MPa of applied uniaxial pressure. Successful fusion of HOD to silicon was achieved at temperatures above 850 °C. Fusion resulted in the formation of an abrupt interface between the wafers in the areas away from diamond grain boundaries. Voids, partially filled with amorphous material, were observed at the fused interface near the diamond grain boundaries. Preferential diamond polishing, potential out-diffusion of hydrogen from diamond and oxygen from silicon are believed to have contributed to the observed non-uniformity of the bonded interface.}, number={10}, journal={DIAMOND AND RELATED MATERIALS}, author={Yushin, GN and Aleksov, A and Wolter, SD and Okuzumi, F and Prater, JT and Sitar, Z}, year={2004}, month={Oct}, pages={1816–1821} }
 @article{wolter_okuzumi_prater_sitar_2003, title={Bias frequency, waveform and duty-cycle effects on the bias-enhanced nucleation of epitaxial diamond}, volume={440}, ISSN={["0040-6090"]}, DOI={10.1016/S0040-6090(03)00827-7}, abstractNote={In contrast to conventional DC bias-enhanced nucleation, a pre-carburization step was not needed in the processing of epitaxial diamond on (1 0 0) silicon using pulsed biasing. Otherwise, the procedure showed little frequency dependence on the epitaxial process in the range of 1 Hz–2 kHz, resulting in a constant percentage of highly oriented diamond of nearly 50%. The only variation with frequency was a linear increase in the bias current and a corresponding decrease in the biasing time required to form a quasi-continuous nucleation layer. In contrast, the variation of a 60-Hz square waveform duty cycle from 3 to 75% showed a decreasing hyperbolic relationship with the percentage of oriented diamond, with a plateau of ∼45% occurring at duty cycles of ⩽17%. The bias time to film formation was also determined to be inversely proportional to the duty cycle. The collective data highlights the relevance of the waveform attributes on the epitaxial nucleation of diamond on (1 0 0) silicon.}, number={1-2}, journal={THIN SOLID FILMS}, author={Wolter, SD and Okuzumi, F and Prater, JT and Sitar, Z}, year={2003}, month={Sep}, pages={145–151} }
 @article{wolter_borca-tasciuc_chen_govindaraju_collazo_okuzumi_prater_sitar_2003, title={Thermal conductivity of epitaxially textured diamond films}, volume={12}, ISSN={["0925-9635"]}, DOI={10.1016/S0925-9635(02)00248-0}, abstractNote={The in-plane thermal conductivity of epitaxially textured, (1 0 0) diamond has been evaluated in comparison to (1 0 0) diamond possessing a random fiber texture. The diamond films were bias-enhanced nucleated using an alternating current source and grown on (1 0 0) silicon using microwave plasma chemical vapor deposition. Thermal conductivity values of ∼1120 (±11%) W/m K and ∼550 (±11%) W/m K were determined for the epitaxial versus non-epitaxial diamond, respectively, using Joule heating thermometry. This twofold improvement in the thermal conductivity of the epitaxially textured diamond is ascribed to a reduction in the grain boundary defects within the film.}, number={1}, journal={DIAMOND AND RELATED MATERIALS}, author={Wolter, SD and Borca-Tasciuc, DA and Chen, G and Govindaraju, N and Collazo, R and Okuzumi, F and Prater, JT and Sitar, Z}, year={2003}, month={Jan}, pages={61–64} }
 @article{wolter_okuzumi_prater_sitar_2002, title={AC vs. DC bias-enhanced nucleation of highly oriented diamond on silicon (100)}, volume={149}, ISSN={["0013-4651"]}, DOI={10.1149/1.1430720}, abstractNote={Bias-enhanced nucleation of highly oriented diamond on silicon (100) has been investigated in the context of bias type. The formation of aligned crystallites using conventional de substrate biasing was facilitated by a preceding carburization. The optimum biasing conditions following a 1 h carburization involved a bias voltage of -250 V and a stringent bias duration of 3-4 min which produced total nucleation densities of ∼1 × 10 10 cm -2 and highly oriented diamond percentages of -50%. In comparison, the application of a 55-65 min ac substrate bias of 175 V rms (±250 V peak-to-peak ) resulted in a comparable percentage of oriented crystallites and similar crystallographic alignment. However, in this approach a precarburization was not found to be beneficial. This simplification in the processing of the oriented diamond was further aided by a broader bias duration window for producing the optimum combination of high total nucleation density and highly oriented diamond percentage.}, number={2}, journal={JOURNAL OF THE ELECTROCHEMICAL SOCIETY}, author={Wolter, SD and Okuzumi, F and Prater, JT and Sitar, Z}, year={2002}, month={Feb}, pages={G114–G117} }
 @article{wolter_yushin_okuzumi_stoner_prater_sitar_2002, title={Direct fusion bonding of silicon to polycrystalline diamond}, volume={11}, ISSN={["0925-9635"]}, DOI={10.1016/S0925-9635(01)00608-2}, abstractNote={High temperature fusion of silicon to diamond is reported. Polished, randomly oriented diamond films and unpolished (100) highly oriented diamond films were bonded to single-side polished (100) silicon in a dedicated ultrahigh vacuum bonding apparatus. Direct bonding under an applied uniaxial stress of ∼32 MPa was observed at temperatures above 950 °C. The bonded interface was examined by scanning acoustic microscopy revealing only partial bonding at fusion temperatures of 950 and 1050 °C. In contrast, complete bonding was evidenced at 1150 and 1200 °C, although cracking of the diamond films became more prominent at these higher fusion temperatures.}, number={3-6}, journal={DIAMOND AND RELATED MATERIALS}, author={Wolter, SD and Yushin, GN and Okuzumi, F and Stoner, BR and Prater, JT and Sitar, Z}, year={2002}, pages={482–486} }
 @article{wolter_schlesser_okuzumi_prater_sitar_2001, title={Angle-dependent reflectometry as a technique for fast assessment of highly oriented diamond film quality}, volume={10}, ISSN={["0925-9635"]}, DOI={10.1016/S0925-9635(01)00487-3}, abstractNote={An expedient technique for assessing the quality of highly oriented diamond films is described. This analysis is based on light reflection from the {111} faces of oriented diamond octahedra as a function of azimuthal sample orientation. Significant light reflection was detected at 90° rotation intervals and the full-width-at-half-maximum of these periodic peaks was determined to be adequate for gauging the upper limit of crystal misorientation. In addition, a two-dimensional surface mapping of the distribution of highly oriented diamond across the sample was determined by analyzing reflectivity properties at equally spaced spots on the surface.}, number={11}, journal={DIAMOND AND RELATED MATERIALS}, author={Wolter, SD and Schlesser, R and Okuzumi, F and Prater, JT and Sitar, Z}, year={2001}, month={Nov}, pages={2092–2095} }
 @article{wolter_okuzumi_prater_sitar_2001, title={Frequency and duty cycle dependence on the pulsed bias-enhanced nucleation of highly oriented diamond on (100) silicon}, volume={186}, ISSN={["0031-8965"]}, DOI={10.1002/1521-396x(200108)186:2<331::aid-pssa331>3.0.co;2-1}, abstractNote={Pulsed bias-enhanced nucleation of highly oriented diamond on (100) silicon is reported. A square waveform substrate bias was implemented in this investigation employing a pulse ON bias voltage of -250 V and a pulse OFF bias voltage of 0 V. An evaluation of the pulse ON fractions of 0.17 and 0.50 revealed a duty cycle dependence on the bias time required for forming a diamond film as well as the highly oriented diamond percentage. Oriented crystallite percentages of nearly 50% and 20% were observed for the 0.17 and 0.50 pulse ON fractions, respectively. Pulse biasing from 10 to 100 Hz (again implementing a square waveform bias and a pulse ON fraction of 0.17) did not influence the process of forming the epitaxial diamond. Throughout this frequency range the onset of diamond film formation was approximately 60 min and a nominal highly oriented diamond percentage of 50% was observed.}, number={2}, journal={PHYSICA STATUS SOLIDI A-APPLIED RESEARCH}, author={Wolter, SD and Okuzumi, F and Prater, JT and Sitar, Z}, year={2001}, month={Jul}, pages={331–337} }
 @article{wolter_schlesser_okuzumi_prater_sitar_2001, title={Process optimization in the low-pressure flat flame growth of diamond}, volume={10}, ISSN={["0925-9635"]}, DOI={10.1016/S0925-9635(00)00477-5}, abstractNote={Abstract The influence of oxy-acetylene gas mixture (O 2 /C 2 H 2 gas ratio — 0.95:1.06) and substrate temperature (ranging from 650 to 850°C) on diamond growth in the low-pressure flat flame is reported. Deconvolution of the Raman spectra was employed to qualitatively estimate the ratio of diamond-to-non-diamond carbon in the film deposits by an area comparison of these discriminate peaks. The diamond crystallinity was assessed quantitatively by a determination of the full-width-at-half-maximum of the 1332 cm −1 Raman line representing sp 3 -bonded carbon. An optimum oxygen/acetylene molar ratio of ∼1.05 and substrate temperature of 650–750°C were observed for limiting both the non-diamond carbon content and a deterioration in the diamond crystallinity. The crystallite morphology was also evaluated as a function of this same parametric regime based on assignment of the parameter α describing growth rate competition between the {100} and {111} faces. The collective data indicates the process conditions required to produce the optimum in film quality according to a desired film morphology.}, number={3-7}, journal={DIAMOND AND RELATED MATERIALS}, author={Wolter, SD and Schlesser, R and Okuzumi, F and Prater, JT and Sitar, Z}, year={2001}, pages={289–294} }