@article{fitting_ware_haywood_walter_nemanich_2005, title={Self-organized nanoscale Ge dots and dashes on SiGe/Si superlattices}, volume={98}, ISSN={["1089-7550"]}, DOI={10.1063/1.1993751}, abstractNote={This study explores the self-organization of Ge nanostructures on SiGe/Si superlattices grown on Si substrates with the surface normal tilted from (001) towards (111) by up to 25°. Prior studies found two-dimensional ordering of Ge dots on nominally flat Si(001) surfaces with a very homogeneous size distribution. Our results show that the Ge islands are less ordered for tilted Si(001) substrates. For substrates with a miscut of 25°, Ge dots nucleate on top of the ripples that form approximately perpendicular to the [1-10]Si direction, i.e., perpendicular to the step direction. Additionally, we observe the formation of Ge dashes, which align preferentially along the [1-10]Si direction.}, number={2}, journal={JOURNAL OF APPLIED PHYSICS}, author={Fitting, L and Ware, ME and Haywood, JR and Walter, JJH and Nemanich, RJ}, year={2005}, month={Jul} }
 @article{ware_nemanich_gray_hull_2004, title={Analysis of a nonorthogonal pattern of misfit dislocation arrays in SiGe epitaxy on high-index Si substrates}, volume={95}, DOI={10.1063/1.1630362}, abstractNote={We have investigated the formation of misfit dislocations resulting from the growth of partially strained Si0.7Ge0.3 epitaxial films on Si substrates with surface normals rotated off of the [001] axis toward [110] by 0°, 13°, and 25°. Transmission electron microscopy has shown that the dislocations form in a modified cross-hatch pattern for samples grown on the off-axis substrates. This modified cross hatch consists of three arrays along which the dislocations align. This is in contrast to the two orthogonal arrays found on the on-axis (001) substrates. These dislocations correspond well with the intersection of the (111) slip planes with the respective surfaces. We present a simple analysis of the amount of relaxation due to probable Burger’s vectors for these dislocations, which reveals the most likely directions for these vectors and shows that the density of dislocations only accounts for a fraction of the total film relaxation as measured by Raman peak shifts. These studies form the basis for the use of high index surfaces as components in modern devices, and provide pathways to possible templates for use in the growth of nanostructures.}, number={1}, journal={Journal of Applied Physics}, author={Ware, M. E. and Nemanich, R. J. and Gray, J. L. and Hull, R.}, year={2004}, pages={115–122} }
 @article{park_sakhrani_maria_cuomo_teng_muth_ware_rodriguez_nemanich_2003, title={Wavelength-dependent Raman scattering of hydrogenated amorphous silicon carbon with red, green, and blue light excitation}, volume={18}, ISSN={["2044-5326"]}, DOI={10.1557/JMR.2003.0106}, abstractNote={This study presents results of wavelength-dependent Raman scattering from amorphous silicon carbon (a-Si:C:H). The a-Si:C:H films were produced by radio-frequency plasma-enhanced chemical vapor deposition. Prior results with amorphous carbon indicate that laser excitation selectively probes clusters with differing sizes. Our measurements with a-Si:C:H indicate that when using red (632.8 nm), green (514.5 nm), and blue (488.0 nm) excitation, the Raman D and G peaks shift to higher wave numbers as the excitation energy increases. The higher frequency is associated with smaller clusters that are preferentially excited with higher photon energy. It appears that photoluminescence occurs due to radiative recombination from intracluster transitions in Si-alloyed sp2-bonded carbon clusters}, number={4}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Park, M and Sakhrani, V and Maria, JP and Cuomo, JJ and Teng, CW and Muth, JF and Ware, ME and Rodriguez, BJ and Nemanich, RJ}, year={2003}, month={Apr}, pages={768–771} }
 @article{gracin_borjanovic_vlahovic_sunda-meya_patterson_dutta_hauger_pinayev_ware_alexson_et al._2001, title={Selective bond breaking in amorphous hydrogenated silicon by using Duke FEL}, volume={475}, ISSN={["0168-9002"]}, DOI={10.1016/S0168-9002(01)01578-9}, abstractNote={In order to study the possibility of influencing the phase containing predominantly Si–H bonds, while having minimal influence on the surrounding materials, samples of a-Si were exposed to Duke-FEL Mark III radiation. The wavelength of the radiation was selected to fit the absorption maximum of stretching vibrations of Si–H bonds (5 μm). By varying the wavelength in the vicinity of 5 μm, the illumination time and the power density, different types and degrees of structural ordering, of Si–H bonds and Si–Si bonds were obtained, and monitored by Raman spectroscopy. By increasing the energy density, at certain level the crystallization occurs. We were able to demonstrate a direct correlation between short and intermediate range ordering and the wavelength and intensity of the radiation. Using 5 μm at 10 kW/cm2 leads to increase in structural disordering. However, increasing power to 60 kW/cm2 improves both short and intermediate order in a-Si : H, as demonstrated by Raman spectroscopy. Further increasing power density by an order of magnitude results in crystallization of the sample.}, number={1-3}, journal={NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT}, author={Gracin, D and Borjanovic, V and Vlahovic, B and Sunda-Meya, A and Patterson, TM and Dutta, JM and Hauger, S and Pinayev, I and Ware, ME and Alexson, D and et al.}, year={2001}, month={Dec}, pages={635–639} }