@article{ives_zeller_lucovsky_schamiloglu_marsden_collins_nichols_karimov_2015, title={Multipactor Coating for Sapphire RF Windows Using Remote Plasma-Assisted Deposition}, volume={43}, ISSN={["1939-9375"]}, DOI={10.1109/tps.2015.2450678}, abstractNote={Traditional application of multipactor coatings applied with sputtering techniques to high-power RF windows typically performs well when applied to sintered powder ceramics. Unfortunately, sputtered coatings do not adhere well to crystal materials, such as sapphire. This publication describes a plasma-assisted process that molecularly bonds the multipactor coating to the base window material. The performance was verified by measuring secondary electron emission yield and operating the window at high power. The coating process and performance are presented.}, number={8}, journal={IEEE TRANSACTIONS ON PLASMA SCIENCE}, author={Ives, Robert Lawrence and Zeller, Daniel and Lucovsky, Gerry and Schamiloglu, Edl and Marsden, David and Collins, George and Nichols, Kimberley and Karimov, Rasul}, year={2015}, month={Aug}, pages={2571–2580} }
 @article{lucovsky_zeller_cheng_zhang_2014, title={Remote plasma-processing (RPP), medium range order, and precursor sites for dangling bond defects in "amorphous-Si(H)" alloys: Photovoltaic and thin film transistor devices}, volume={242}, ISSN={["0257-8972"]}, DOI={10.1016/j.surfcoat.2013.06.104}, abstractNote={Remote plasma processing (RPP) provides pathways to the formation of photovoltaic (PV) and thin-film-transistor (TFT) devices that include buried interfaces. This is made possible by separate and independent control of (i) plasma excited O- and N-atom deposition precursors in a up-stream plasma chamber, combined with (ii) down-stream injection of Si- and Ge-atoms with control gas flow rates providing control of buried interface bonding at monolayer levels. Devices with intrinsic, B p-type and P n-type "a-Si(H)" & "a-Si,Ge(H)" layers require 10% bonded H in monolayer (SiH arrangements) and deposition and/or annealing at temperatures between 240 and 275 °C. Deposition from SiH4 with either PH3 or B2H6 dopant gasses provides spectrally reflecting films which can be annealed yielding fine-grain films for gate, or source and drain regions for TFTs or FETs.}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Lucovsky, G. and Zeller, D. J. and Cheng, C. and Zhang, Y.}, year={2014}, month={Mar}, pages={183–186} }
 @article{lucovsky_kim_wu_zeller_2013, title={Noncrystalline SiO2 and GeO2: Process induced pre-existing defects and vacated O-atom intrinsic bonding sites}, volume={31}, ISSN={["2166-2746"]}, DOI={10.1116/1.4773923}, abstractNote={Electron spin resonance (ESR) studies on bulk-quenched, noncrystalline (nc-) silica glasses (henceforth, nc-SiO2) have distinguished between (1) pre-existing process-induced defects introduced either after growth or annealing at high temperatures and (2) x-ray or γ-ray radiation or energetic electron particle-created defects. The ESR activity in these pre-existing defects is activated by x-rays. Similar pre-exiting defects have been demonstrated for remote plasma-deposited thin films of nc-SiO2 and nc-GeO2. Concentrations of pre-existing defects increase exponentially with increasing quenching and annealing temperatures. This is always the case for so-called “dry silicas” with no detectable Si–OH bonding. Nonbonding O-hole centers or nonbonding O-associated hole centers are also detected in dry silicas but only after significant x-ray, γ-ray, or energetic electron irradiation. Pre-existing defect has also been detected by second derivative O K pre-edge x-ray absorption spectroscopy in thermally grown and remote plasma-deposited nc-SiO2 and nc-GeO2 thin films. These spectra display singlet and triplet features that can be symmetry state labeled according to Tanabe–Sugano diagrams. This is demonstrated by combining ab initio theory and experiment by identifying the pre-existing defects as vacated O-atom sites in which an O-atom has never been resident.}, number={1}, journal={JOURNAL OF VACUUM SCIENCE & TECHNOLOGY B}, author={Lucovsky, Gerald and Kim, Jinwoo and Wu, Kun and Zeller, Daniel}, year={2013}, month={Jan} }
 @article{lucovsky_zeller_kim_wu_2013, title={Process induced pre-existing defects in non-crystalline SiO2 and GeO2 at vacated O-atom bonding sites and comparisons with Ge-S(Se) alloy bonding sites}, volume={428}, ISSN={["1742-6596"]}, DOI={10.1088/1742-6596/428/1/012017}, abstractNote={Three related topics are addressed in this article: (i) X-ray spectroscopy (XAS) studies of remote plasma deposited (RPD) nc-SiO2 and nc-GeO2 emphasizing (a) band-edge states and (b) pre-existing bonding defects; (ii) interpretation of X-ray absorption and photoemission spectra based on many electron theory, and in particluar charge transfer multiplets (CTs); and (iii) band-edge electronic structure and intrinsic defects in nc-SiO2 and nc-GeO2 thin films and their interfaces with Si and Ge substrates. The most significant result is the identification of local atomic structure in medium range order (MRO) clusters in which the pre-existing defects are embedded. These defects are vacated O-atom sites in which O-atoms have never been resident. They are confined to 1 nm scale chemically-ordered clusters distributed non-periodically with quartz-structured 4-fold coordinated Si(Ge) and 2-fold coordinated O bonding in 12-atom regular rings. Vacated O-atom sites defects are formed during processing and annealing, and reducing macroscopic as well as local bond-strain strain. They are qualitatively different, and readily distinguished from defects introduced by electrical, and by X-ray, γ-ray or high energy electron stressing of nc-SiO2 and nc-GeO2.}, journal={XXIST INTERNATIONAL SYMPOSIUM ON THE JAHN-TELLER EFFECT 2012}, author={Lucovsky, Gerald and Zeller, Daniel and Kim, JinWoo and Wu, Kun}, year={2013} }
 @article{lucovsky_parsons_zeller_kim_2013, title={Spectroscopic Detection of Medium Range Order in Device Grade Hydrogenated Amorphous Silicon}, volume={52}, ISSN={["1347-4065"]}, DOI={10.7567/jjap.52.04cr10}, abstractNote={ 
 This article addresses low defect densities in hydrogenated amorphous silicon, a-Si1-x
                  :H
                     x
                   with approximately 10 at. % bonded H, x∼0.1. Based low defect densities at mid-gap, ∼0.5 to 1×1016 cm-3, a-Si:H thin films have been integrated into photovoltaic (PV) devices and thin film transistors (TFT's). Amorphous Si (a-Si) thin films with no detectable bonded-H have been used as precursors for polycrystalline gate electrodes in microelectronic applications. PV and TFT alloys have been deposited by glow discharge (GD), remote plasma-enhanced chemical vapor deposition (RPECVD), and reactive magnetron sputtering (RMS) with different bonded-H content determined by deposition precursors and substrate temperatures. Two conditions are required for the lowest Si dangling bond densities: (i) a monohydride, Si–H, concentration of ∼10 at. % H, and (ii) deposition, and/or a post-deposition annealing at 240 to 300 °C. 
 }, number={4}, journal={JAPANESE JOURNAL OF APPLIED PHYSICS}, author={Lucovsky, Gerry and Parsons, Greg and Zeller, Daniel and Kim, Jinwoo}, year={2013}, month={Apr} }
 @article{lucovsky_kim_wu_zeller_papas_whitten_2011, title={Non-crystalline SiO(2): processing induced pre-existing defects associated with vacated O-atom intrinsic bonding sites}, volume={13}, number={11-12}, journal={Journal of Optoelectronics and Advanced Materials}, author={Lucovsky, G. and Kim, J. W. and Wu, K. and Zeller, D. and Papas, B. and Whitten, J. L.}, year={2011}, pages={1359–1363} }
 @article{lucovsky_zeller_whitten_2011, title={O-vacancies in transition metal (TM) oxides: Coordination and local site symmetry of transition and negative ion states in TM2O3 and TMO2 oxides}, volume={88}, ISSN={0167-9317}, url={http://dx.doi.org/10.1016/j.mee.2011.03.153}, DOI={10.1016/j.mee.2011.03.153}, abstractNote={Removal of neutral O-atoms from a transition metal (TM) oxide results in two electrons residing within the vacated site. Two-electron multiplet theory has been used to develop a d2 equivalent model. When applied to tetragonal HfO2, the two electrons of neutral vacancy in the d2 equivalent limit reside on two Hf d-state orbitals in a high-spin configuration. Transition energies and negative ion state features are detected in transition metal (TM) oxides by X-ray absorption spectroscopy (XAS) in the O K pre-edge/sub-band gap energy regime, and are compared with the model. These transitions are from the O 1s2 doubly occupied core level approximately 543 eV below vacuum, and terminate in empty virtual bound states. In addition these strong spin-allowed transitions, spectra include weaker features corresponding to either spin-forbidden transitions in the d2 model, or alternatively to a near-degeneracy with a singlet ground state with weak Hf-atom pair bonds. The analysis of O K edge XAS spectra identify a significant distinction between multiplet (i) triplet transition energies for neutral O-vacancies that are not active as electron or hole traps, (ii) O-vacancy negative ion states that are active as electron traps in Poole–Frenkel conduction or trap-assisted tunneling (TAT), and (iii) O-vacancy occupied ground states that can trap holes.}, number={7}, journal={Microelectronic Engineering}, publisher={Elsevier BV}, author={Lucovsky, G. and Zeller, D. and Whitten, J.L.}, year={2011}, month={Jul}, pages={1471–1474} }
 @article{lucovsky_zeller_2011, title={Remote Plasma Enhanced Chemical Deposition of Non-Crystalline GeO2 on Ge and Si Substrates}, volume={11}, ISSN={["1533-4880"]}, DOI={10.1166/jnn.2011.5090}, abstractNote={Non-crystalline GeO2 films remote were plasma deposited at 300 degrees C onto Ge substrates after a final rinse in NH4OH. The reactant precursors gas were: (i) down-stream injected 2% GeH4 in He as the Ge precursor, and (ii) up-stream, plasma excited O2-He mixtures as the O precursor. Films annealed at 400 degrees C displayed no evidence for loss of O resulting in Ge sub-oxide formation, and for a 5-6 eV mid-gap absorption associated with formation of GeOx suboxide bonding, x < 2. These films were stable in normal laboratory ambients with no evidence for reaction with atmospheric water. Films deposited on Ge and annealed at 600 degrees C and 700 degrees C display spectra indicative of loss of O-atoms, accompanied with a 5.5 eV absorption. X-ray absorption spectroscopy and many-electron theory are combined to describe symmetries and degeneracies for O-vacancy bonding defects. These include comparisons with remote plasma-deposited non-crystalline SiO2 on Si substrates with SiON interfacial layers. Three different properties of remote plasma GeO2 films are addressed comparisons between (i) conduction band and band edge states of GeO2 and SiO2, and (ii) electronic structure of O-atom vacancy defects in GeO2 and SiO2, and differences between (iii) annealing of GeO2 films on Ge substrates, and Si substrates passivated with SiON interfacial transition regions important for device applications.}, number={9}, journal={JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY}, author={Lucovsky, Gerald and Zeller, Daniel}, year={2011}, month={Sep}, pages={7974–7981} }
 @article{lucovsky_zeller_wu_whitten_2011, title={Remote plasma-deposited GeO2 with quartz-like Ge- and O-local bonding: Band-edge state and O-vacancy comparisons with SiO2}, volume={88}, ISSN={0167-9317}, url={http://dx.doi.org/10.1016/j.mee.2011.03.152}, DOI={10.1016/j.mee.2011.03.152}, abstractNote={X-ray absorption spectroscopy (XAS) and many-electron theory are combined to describe symmetries and degeneracies for intrinsic bonding defects in remote plasma-deposited (rpd-) non-crystalline (nc-), rpd-nc-GeO2 and rpd-nc-SiO2, hereafter simply GeO2 and SiO2. GeO2 is emerging as an alternative gate dielectric for nano-CMOS devices. High resolution O-vacancy spectral features in O K pre-edge spectra for SiO2 have been assigned to multiplet transitions and negative ion states based on an extended d2 equivalent model, including both weaker singlet and as well the stronger triplet transitions discussed in previous publications. This has revealed predominantly mid-gap Ge and Si singlet and triplet bonding arrangements for the electrons in O-vacancy sites. These have been examined as a function of post deposition rapid thermal annealing in Ar ambients for GeO2 deposited at 300 °C on both Si and Ge substrates, identifying different post-deposition thermal budget processing windows for low defect density GeO2 on Si and Ge substrates. For ultra thin nitrided SiOx, x < 2 interfacial layers on Si, this is at least 700 °C, but on Ge, independent of surface processing it less than 600 °C.}, number={7}, journal={Microelectronic Engineering}, publisher={Elsevier BV}, author={Lucovsky, G. and Zeller, D. and Wu, K. and Whitten, J.L.}, year={2011}, month={Jul}, pages={1537–1540} }
 @article{lucovsky_parsons_zeller_wu_papas_whitten_lujan_street_2011, title={Spectroscopic detection of medium range order in device quality hydrogenated amorphous silicon, a-Si(H)}, volume={13}, number={11-12}, journal={Journal of Optoelectronics and Advanced Materials}, author={Lucovsky, G. and Parsons, G. and Zeller, D. and Wu, K. and Papas, B. and Whitten, J. and Lujan, R. and Street, R. A.}, year={2011}, pages={1586–1589} }