@article{mcginnis_thomson_davis_chen_michel_lamb_2001, title={In situ cleaning of GaN/6H-SiC substrates in NH3}, volume={222}, ISSN={["0022-0248"]}, DOI={10.1016/s0022-0248(00)00947-7}, abstractNote={Metalorganic chemical vapor deposition-grown GaN on 6H-SiC substrates were cleaned by annealing in an NH3 flux. Oxygen contamination was removed by thermal desorption, and carbon removal was facilitated by reaction with NH3. The GaN(0 0 0 1) surface after NH3 beam cleaning at 730°C was smooth with distinct atomic steps. The roughness (0.20 nm RMS) was only slightly greater than that of the untreated substrate (0.17 nm RMS). Carbon and oxygen concentrations were reduced to background levels (∼1 at%) by annealing in an NH3 flux at 800°C. The surface step structure was destroyed by annealing in an NH3 flux of 4×1015 cm−2 s−1 from a seeded supersonic beam; however, annealing in an NH3 flux of 7×1015 cm−2 s−1 from a leak valve inhibited surface roughening and produced a relatively smooth surface (0.28 nm RMS) with a 3×3 R30° reconstruction. We infer from the effects of annealing temperature and NH3 flux that the observed surface roughening is due to GaN decomposition.}, number={3}, journal={JOURNAL OF CRYSTAL GROWTH}, author={McGinnis, AJ and Thomson, D and Davis, RF and Chen, E and Michel, A and Lamb, HH}, year={2001}, month={Jan}, pages={452–458} }
 @article{mcginnis_thomson_davis_chen_michel_lamb_2001, title={Kinetics and gas-surface dynamics of GaN homoepitaxial growth using NH3-seeded supersonic molecular beams}, volume={494}, ISSN={["1879-2758"]}, DOI={10.1016/S0039-6028(01)01466-2}, abstractNote={The kinetics of homoepitaxial growth of GaN thin films on metal-organic chemical vapor deposition (MOCVD)-grown GaN(0 0 0 1)/AlN/6H-SiC substrates was probed using NH3-seeded supersonic molecular beams. NH3 was seeded in H2 and He and antiseeded in N2 and Ar in order to obtain incident kinetic energies of 0.08–1.8 eV. Nozzle temperatures of 35–600 °C were used to adjust the NH3 internal energy. Intense NH3 beams (fluxes >2×1015cm−2s−1 at the substrate) are produced for low seeding percentages (<5%) in the lighter carrier gases, because the heavier species (NH3) is focused along the centerline of the beam. The NH3 flux is proportional to the ratio of its molecular weight to the average molecular weight of the binary gas mixture. A steady-state Langmuir–Hinshelwood kinetics model was used to extract zero-coverage NH3 sticking coefficient (αNH30) values from GaN growth kinetics data. An αNH30 value of 0.14 at 750 °C was determined using seeded supersonic beams of NH3 in He with incident kinetic energies of 0.4–0.5 eV. In comparison, GaN growth rates using low-energy NH3 molecules (0.03 eV) from a leak valve indicate an αNH30 of 0.29. Growth rate measurements using NH3 beams with kinetic energies of 0.08–1.8 eV confirmed that αNH30 generally decreases with increasing incident kinetic energy, leading us to conclude that NH3 chemisorption on GaN(0 0 0 1) is unactivated and occurs via a precursor-mediated mechanism. Internal energy enhancement of NH3 chemisorption via a precursor-mediated channel is proposed to explain the effects of nozzle temperature on GaN growth kinetics. The effects of NH3 incident kinetic energy on film morphology are indirect. Rough, highly faceted films are observed under Ga-limited growth conditions. The surface morphology of films grown under NH3-limited conditions changes from rough to smooth as the effective V/III ratio is decreased.}, number={1}, journal={SURFACE SCIENCE}, author={McGinnis, AJ and Thomson, D and Davis, RF and Chen, E and Michel, A and Lamb, HH}, year={2001}, month={Nov}, pages={28–42} }
 @article{michel_hanser_davis_qiao_lau_yu_sun_asbeck_2000, title={Growth and characterization of piezoelectrically enhanced acceptor-type AlGaN/GaN heterostructures}, volume={5}, journal={MRS Internet Journal of Nitride Semiconductor Research}, author={Michel, A. and Hanser, D. and Davis, R. F. and Qiao, D. and Lau, S. S. and Yu, L. S. and Sun, W. and Asbeck, P.}, year={2000}, pages={U520–525} }
 @inproceedings{michel_felder_genzer_fuller_2000, title={Student use of instructional technology in the introductory chemical engineering course}, DOI={10.18260/1-2--28492}, abstractNote={An introductory computer engineering course where students learn about combinational and sequential circuits is fundamental to any Electrical and Computer Engineering (ECE) curriculum. Many of these courses are taught using a hardware description language (HDL) such as Verilog or VHDL. However, younger students traditionally struggle with HDLs due to their abstract nature. The students are used to designing with traditional logic gates and structures, but are often confused by the software-like interface that an HDL provides. This creates a disconnection between the student's experience in the classroom where the students learn with one method (visually with gates and structures) and in labs or projects where they are asked to implement designs using text descriptors. Often times a student's frustration with HDLs leads to them being disinterested in digital systems or even computer engineering as a major. This paper will describe the transition of an introductory Computer Engineering course from primarily using Verilog for its assignments to instead using a combination of schematic capture (which is very similar to what they see in class) and Verilog. With this course's redesign, the author saw the student's self-reported confidence in their design skills improve by 44% (from 41% to 85%) and their interest in taking additional computer engineering courses improve by 10% (from 66% to 76%).}, booktitle={2000 ASEE Annual Conference Proceedings, ASEE, June 2000}, publisher={Washington, D.C.: American Society for Engineering Education}, author={Michel, A. and Felder, R.M. and Genzer, Jan and Fuller, H.}, year={2000} }