@article{lindquist_jarrendahl_peters_zettler_cobet_esser_aspnes_henry_edwards_2001, title={Ordinary and extraordinary dielectric functions of 4H-and 6H-SiC from 3.5 to 9.0 eV}, volume={78}, ISSN={["0003-6951"]}, DOI={10.1063/1.1369617}, abstractNote={We report ordinary (ε⊥c axis) and extraordinary (ε∥c axis) dielectric function data of 4H– and 6H–SiC from 3.5 to 9.0 eV. These data, which were obtained by with spectroscopic ellipsometry, are also compared to recently reported ab initio calculations. Critical point energies were found using real and reciprocal space analysis.}, number={18}, journal={APPLIED PHYSICS LETTERS}, author={Lindquist, OPA and Jarrendahl, K and Peters, S and Zettler, JT and Cobet, C and Esser, N and Aspnes, DE and Henry, A and Edwards, NV}, year={2001}, month={Apr}, pages={2715–2717} }
 @article{ronning_dalmer_uhrmacher_restle_vetter_ziegeler_hofsass_gehrke_jarrendahl_davis_2000, title={Ion implanted dopants in GaN and AlN: Lattice sites, annealing behavior, and defect recovery}, volume={87}, ISSN={["1089-7550"]}, DOI={10.1063/1.372154}, abstractNote={The recovery of structural defects in gallium nitride (GaN) and aluminum nitride (AlN) after implantation of In+111 and Sr+89 in the dose range (0.1–3) 1013 cm−2 and ion energies of 60–400 keV has been investigated as a function of annealing temperature with emission channeling (EC) and perturbed γγ angular correlation spectroscopy. The implanted In and Sr atoms occupied substitutional sites in heavily perturbed surroundings of point defects after room temperature implantation. No amorphization of the lattice structure was observed. The point defects could be partly removed after annealing to 1473 K for 10–30 min. Lattice site occupation of implanted light alkalis, Na+24 in GaN and AlN as well as Li+8 in AlN, were also determined by EC as a function of implantation and annealing temperature. These atoms occupied mainly interstitial sites at room temperature. Lithium diffusion and the occupation of substitutional sites was observed in GaN and AlN at implantation temperatures above 700 K. A lattice site change was also observed for sodium in AlN, but not in GaN after annealing to 1073 K for 10 min.}, number={5}, journal={JOURNAL OF APPLIED PHYSICS}, author={Ronning, C and Dalmer, M and Uhrmacher, M and Restle, M and Vetter, U and Ziegeler, L and Hofsass, H and Gehrke, T and Jarrendahl, K and Davis, RF}, year={2000}, month={Mar}, pages={2149–2157} }
 @article{edwards_madsen_robbie_powell_jarrendahl_cobet_esser_richter_aspnes_2000, title={Real-time assessment of overlayer removal on 4H-SiC surfaces: Techniques and relevance to contact formation}, volume={338-3}, ISBN={["*************"]}, ISSN={["0255-5476"]}, DOI={10.4028/www.scientific.net/msf.338-342.1033}, abstractNote={We applied real-time spectroscopic ellipsometric (SE) measurements to assess the removal of overlayer material from 4H-SiC Si- and C-face surfaces in order to investigate the final step of an other ...}, number={3}, journal={SILICON CARBIDE AND RELATED MATERIALS - 1999 PTS, 1 & 2}, author={Edwards, NV and Madsen, LD and Robbie, K and Powell, GD and Jarrendahl, K and Cobet, C and Esser, N and Richter, W and Aspnes, DE}, year={2000}, pages={1033–1036} }
 @article{edwards_jarrendahl_aspnes_robbie_powell_cobet_esser_richter_madsen_2000, title={Real-time assessment of selected surface preparation regimens for 4H-SiC surfaces using spectroscopic ellipsometry}, volume={464}, ISSN={["1879-2758"]}, DOI={10.1016/S0039-6028(00)00689-0}, abstractNote={Spectroscopic ellipsometry (SE) was used to assess the removal of overlayer material from 4H–SiC (0001) and (0001) [Si- and C-face] surfaces in real time and, in particular, the critical final step of an otherwise standard RCA cleaning regimen commonly used to prepare SiC surfaces for contact formation. The treatments selected [buffered hydrofluoric acid (HF), concentrated HF, and dilute HF] removed 4–40 Å of effective SiO2 overlayer thickness from these surfaces. The concentrated HF treatment yielded the best surface, i.e. that with the most abrupt transition region between bulk and surface and with the most oxide material removed. A fourth treatment regimen (sequential application of methanol, water, and 5% HF in methanol) was also developed for comparison with the full RCA clean.}, number={1}, journal={SURFACE SCIENCE}, author={Edwards, NV and Jarrendahl, K and Aspnes, DE and Robbie, K and Powell, GD and Cobet, C and Esser, N and Richter, W and Madsen, LD}, year={2000}, month={Sep}, pages={L703–L707} }
 @article{jarrendahl_smith_zheleva_kern_davis_1998, title={Growth of highly (0001)-oriented aluminum nitride thin films with smooth surfaces on silicon carbide by gas-source molecular beam epitaxy}, volume={49}, ISSN={["0042-207X"]}, DOI={10.1016/S0042-207X(97)00177-2}, abstractNote={Aluminum nitride thin films with very smooth surfaces have been grown by gas-source molecular beam epitaxy on 4H and 6H silicon carbide substrates. High purity ammonia was used as the nitrogen source in conjunction with Al evaporated from an effusion cell. Streaked reflection high energy electron diffraction patterns and reconstructions of the AlN surfaces indicated smooth films. This surface character was confirmed via atomic force microscopy and transmission electron microscopy which showed roughness root mean square values typically below 1 nm and very flat surfaces, respectively. X-ray diffraction showed the films to be highly c-axis oriented and single phase. Major impurities in the AlN films were oxygen and carbon, as revealed by secondary ion mass spectrometry.}, number={3}, journal={VACUUM}, author={Jarrendahl, K and Smith, SA and Zheleva, T and Kern, RS and Davis, RF}, year={1998}, month={Mar}, pages={189–191} }
 @article{jarrendahl_davis_1998, title={Materials properties and characterization of SiC}, volume={52}, ISBN={["0-12-752160-7"]}, ISSN={["0080-8784"]}, DOI={10.1016/S0080-8784(08)62843-4}, abstractNote={This chapter discusses the materials properties and characterization of silicon carbide (Sic). Wide energy bandgaps, high thermal conductivity, high-saturated electron drift velocities, and high-breakdown electric fields make Sic a candidate of choice for high-temperature, high-speed, high-frequency, and high-power applications. In a polytypic compound, similar sheets of atoms or symmetrical variants are stacked atop each other and related according to a symmetry operator. The most stable way to stack an identical second sheet of close-packed spheres is to place the spheres atop the valleys in the first sheet. The Sic polytypes can be n-type doped using nitrogen or phosphorus as donors and p-type using boron, aluminum, or gallium as acceptors. In general, unintentionally doped Sic has n-type conductivity because of nitrogen donors included as a contaminant during the production of the material. The electron and hole mobilities in Sic are a function of the nature of the material (carrier concentration, polytype, structural quality) and temperature.}, journal={SIC MATERIALS AND DEVICES}, author={Jarrendahl, K and Davis, RF}, year={1998}, pages={1–20} }
 @article{jarrendahl_arwin_1998, title={Multiple sample analysis of spectroscopic ellipsometry data of semi-transparent films}, volume={313}, ISSN={["0040-6090"]}, DOI={10.1016/S0040-6090(97)00781-5}, abstractNote={When analyzing spectroscopic ellipsometry data it can be difficult to find unique solutions if, for instance, the dielectric function of a film must be found together with the film thickness. One method to find the solutions is `multiple sample analysis'. The basic assumption for this method is that the optical properties of the unknown layers are identical in all samples. In the analysis procedure a set of samples with different film thicknesses are prepared and measured, preferably at multiple angles of incidence. Several (one for each sample) identical optical models are then defined with coupled optical properties of the unknown layers and all data are fitted simultaneously. This will give solutions for the dielectric function of the films and the film thicknesses due to parameter decoupling. The analysis can also be extended to more complex samples including more than one film thickness, surface and interface roughness, and porosity. In this study we have applied the multiple sample analysis method to find dielectric functions, film thicknesses and surface roughnesses of thin films of Ta2O5, ScN and CeO2.}, journal={THIN SOLID FILMS}, author={Jarrendahl, K and Arwin, H}, year={1998}, month={Feb}, pages={114–118} }
 @article{kern_jarrendahl_tanaka_davis_1997, title={Growth and doping via gas-source molecular beam epitaxy of SiC and SiC/AlN heterostructures and their microstructural and electrical characterization}, volume={6}, ISSN={["0925-9635"]}, DOI={10.1016/S0925-9635(97)00066-6}, abstractNote={Gas-source molecular beam epitaxy has been employed to grown thin films of SiC and AlN on vicinal and on-axis 6H-SiC(0001). Growth using the SiH4C2H4 system resulted in 3C-SiC(111) epilayers under all conditions of reactant gas flow and temperatures. Films of 6H-SiC(0001) were deposited on vicinal 6H-SiC(0001) substrates using the SiH4C2H4H2 system at deposition temperatures ⩾ 1350°C. In situ doping was achieved by intentional introduction of nitrogen and aluminum into the growing crystal. Monocrystalline AlN was deposited using evaporated Al and ECR plasma derived N or NH3. Films <50 Å grown on the vicinal substrates had higher defect densities compared to those on the on-axis substrates due to the higher density of inversion boundaries forming at most SiC steps in the former material. Metal/AlN/6H-SiC(0001) thin film heterostructures which had a density of trapped charges as low as of 1 × 1011 cm−2 at room temperature were prepared without post growth treatment. Superior single crystal AlNSiC heterostructures were achieved when very thin AlN was deposited on the on-axis substrates. Single phase monocrystalline solid solutions of (AlN)x(SiC)1−x were deposited between 0.2 ≤ x ≤ 0.8. A transition from the zincblende to the wurtzite structure was observed at x ≈ 0.25.}, number={10}, journal={DIAMOND AND RELATED MATERIALS}, author={Kern, RS and Jarrendahl, K and Tanaka, S and Davis, RF}, year={1997}, month={Aug}, pages={1282–1288} }
 @article{kern_jarrendahl_tanaka_davis_1997, title={Homoepitaxial SiC growth by molecular beam epitaxy}, volume={202}, number={1}, journal={Physica Status Solidi. B, Basic Solid State Physics}, author={Kern, R. S. and Jarrendahl, K. and Tanaka, S. and Davis, R. F.}, year={1997}, pages={379–404} }
 @article{jarrendahl_ivanov_sundgren_radnoczi_czigany_greene_1997, title={Microstructure evolution in amorphous Ge/Si multilayers grown by magnetron sputter deposition}, volume={12}, ISSN={["0884-2914"]}, DOI={10.1557/JMR.1997.0249}, abstractNote={Microstructure evolution in amorphous Ge/Si multilayers grown by dual-target dc magnetron sputtering was investigated by cross-sectional transmission electron microscopy, x-ray diffraction, and growth simulations. In films grown under low intensity ion-irradiation conditions, the structure is columnar with low-density regions along column boundaries where layer intermixing was observed. By increasing the low-irradiation intensity (controlled by an applied negative substrate-bias), structures with smooth and well-defined layers could be grown. This was achieved at bias voltages between 80 and 140 V, depending on the sputtering gas pressure. As the ion-irradiation intensity is further increased, ion-induced intermixing degrades the layer interfaces and finally an amorphous Si1−xGex alloy forms. The combination of x-ray diffraction measurements and reflectivity calculations reveals an asymmetry between the Ge/Si and Si/Ge interface widths due, primarily, to a corresponding asymmetry in incident particle energies during the growth of alternate layers.}, number={7}, journal={JOURNAL OF MATERIALS RESEARCH}, author={Jarrendahl, K and Ivanov, I and Sundgren, JE and Radnoczi, G and Czigany, Z and Greene, JE}, year={1997}, month={Jul}, pages={1806–1815} }