Jeffrey Stevens
Sandia National Laboratories
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Publication
Featured researches published by Jeffrey Stevens.
Physical Review Letters | 2012
James C. Ginn; Igal Brener; David W. Peters; Joel R. Wendt; Jeffrey Stevens; Paul Hines; Lorena I. Basilio; Larry K. Warne; Jon F. Ihlefeld; Paul G. Clem; Michael B. Sinclair
We demonstrate, for the first time, an all-dielectric metamaterial resonator in the mid-wave infrared based on high-index tellurium cubic inclusions. Dielectric resonators are desirable compared to conventional metallo-dielectric metamaterials at optical frequencies as they are largely angular invariant, free of ohmic loss, and easily integrated into three-dimensional volumes. With these low-loss, isotropic elements, disruptive optical metamaterial designs, such as wide-angle lenses and cloaks, can be more easily realized.
Physical Review B | 2009
Eric Nordberg; G. A. Ten Eyck; Harold Stalford; Richard P. Muller; Ralph W. Young; K. Eng; Lisa A Tracy; Kenton D. Childs; Joel R. Wendt; Robert K. Grubbs; Jeffrey Stevens; M. P. Lilly; M. A. Eriksson; Malcolm S. Carroll
We present measurements of silicon (Si) metal-oxide-semiconductor (MOS) nanostructures that are fabricated using a process that facilitates essentially arbitrary gate geometries. Stable Coulomb-blockade behavior showing single-period conductance oscillations that are consistent with a lithographically defined quantum dot is exhibited in several MOS quantum dots with an open-lateral quantum-dot geometry. Decreases in mobility and increases in charge defect densities (i.e., interface traps and fixed-oxide charge) are measured for critical process steps, and we correlate low disorder behavior with a quantitative defect density. This work provides quantitative guidance that has not been previously established about defect densities and their role in gated Si quantum dots. These devices make use of a double-layer gate stack in which many regions, including the critical gate oxide, were fabricated in a fully qualified complementary metal-oxide semiconductor facility.
Applied Physics Letters | 2009
Eric Nordberg; Harold Stalford; Ralph W. Young; G. A. Ten Eyck; K. Eng; Lisa A Tracy; Kenton D. Childs; Joel R. Wendt; Robert K. Grubbs; Jeffrey Stevens; M. P. Lilly; M. A. Eriksson; Malcolm S. Carroll
Laterally coupled charge sensing of quantum dots is highly desirable because it enables measurement even when conduction through the quantum dot itself is suppressed. In this work, we demonstrate such charge sensing in a double-top-gated metal-oxide-semiconductor system. The current through a point contact constriction integrated near a quantum dot shows sharp 2% changes corresponding to charge transitions between the dot and a nearby lead. We extract the coupling capacitance between the charge sensor and the quantum dot, and we show that it agrees well with a three-dimensional capacitance model of the integrated sensor and quantum dot system.
Applied Physics Letters | 2010
Lisa A Tracy; Eric Nordberg; Ralph W. Young; C. Borras Pinilla; Harold Stalford; G. A. Ten Eyck; K. Eng; Kenton D. Childs; Joel R. Wendt; Robert K. Grubbs; Jeffrey Stevens; M. P. Lilly; M. A. Eriksson; Malcolm S. Carroll
We present transport measurements of a tunable silicon metal-oxide semiconductor double quantum dot device with lateral geometry. The experimentally extracted gate-to-dot capacitances show that the device is largely symmetric under the gate voltages applied. Intriguingly, these gate voltages themselves are not symmetric. A comparison with numerical simulations indicates that the applied gate voltages serve to offset an intrinsic asymmetry in the physical device. We also show a transition from a large single dot to two well isolated coupled dots, where the central gate of the device is used to controllably tune the interdot coupling.
IEEE Transactions on Nuclear Science | 2011
James R. Schwank; M.R. Shaneyfelt; Paul E. Dodd; Dale McMorrow; Gyorgy Vizkelethy; V. Ferlet-Cavrois; Pascale M. Gouker; Richard S. Flores; Jeffrey Stevens; Stephen B. Buchner; Scott M. Dalton; Scot E. Swanson
The amounts of charge collection by single-photon absorption (SPA) and by two-photon absorption (TPA) laser testing techniques have been directly compared using specially made SOI diodes. For SPA measurements and some TPA measurements, the back substrates of the diodes were removed by etching with XeF2. With the back substrates removed, the amount of TPA induced charge collection can be correlated to the amount of SPA induced charge collection. There are significant differences, however, in the amount of TPA induced charge collection for diodes with and without substrates. For the SOI diodes of this study, this difference appears to arise from several contributions, including nonlinear-optical losses and distortions that occur as the pulse propagates through the substrate, as well as displacement currents that occur only when the back substrate is present. These results illustrate the complexity of interpreting TPA and SPA single-event upset measurements.
european conference on radiation and its effects on components and systems | 2011
M.R. Shaneyfelt; James R. Schwank; Paul E. Dodd; Jeffrey Stevens; Gyorgy Vizkelethy; Scot E. Swanson; Scott M. Dalton
Techniques for removing the back substrate of SOI devices are described for both packaged devices and devices at the die level. The use of these techniques for microbeam, heavy-ion, and laser testing are illustrated.
Journal of Vacuum Science & Technology. B. Nanotechnology and Microelectronics: Materials, Processing, Measurement, and Phenomena | 2012
E. A. Douglas; Jeffrey Stevens; Kira L. Fishgrab; Christine Ford; R. J. Shul; S. J. Pearton
Highly anisotropic features of benzocyclobutene, a promising low stress layer for microelectromechanical systems, were achieved by inductively coupled plasma (ICP) etching with fluorine/oxygen based chemistry. The effects of chamber pressure, platen power, ICP power, and SF6/O2 relative concentration were studied on etch rate, selectivity, and sidewall morphology. Highly anisotropic features were achieved with sidewall slopes ∼88° for almost all conditions. Grass-like residue, due to redeposition of etch material, was observed under certain conditions and is shown to be dependent on pressure, ICP power, and feature dimensions.
Journal of Electronic Materials | 2009
Mary A. Miller; Mary H. Crawford; A. A. Allerman; Karen Charlene Cross; M.A. Banas; R. J. Shul; Jeffrey Stevens; Katherine H. A. Bogart
41st International Symposium for Testing and Failure Analysis (November 1 - 5, 2015) | 2015
Joshua Beutler; John Joseph Clement; Edward I. Cole; Jeffrey Stevens; V. Carter Hodges; Scott Silverman; Robert Chivas
40th International Symposium for Testing and Failure Analysis (ISTFA 2014) | 2014
Joshua Beutler; Edward I. Cole; Mary A. Miller; John Joseph Clement; Jeffrey Stevens