Dr. Jacob H. Leach Profile

Dr. Jacob H. Leach

at Kyma Technologies Inc

SPIE Involvement:

Author

Publications (26)

Proceedings Article | 8 March 2024 Presentation + Paper

Toward high-throughput deposition of III-V materials and devices using halide vapor phase epitaxy

A. Ptak, M. Hassanaly, K. Udwary, J. Leach, G. Dodson, H. Splawn, K. Schulte, J. Simon

Proceedings Volume 12881, 1288102 (2024) https://doi.org/10.1117/12.3003229

KEYWORDS: Vacuum chambers, Design, Solar cells, Vapor phase epitaxy, Semiconducting wafers, Modeling, Transistors, Light emitting diodes, Indium gallium phosphide, Gallium arsenide

Read Abstract +

Proceedings Article | 27 March 2020 Presentation

HVPE growth of [beta]-Ga2O3 films for devices on bulk and thermally enhanced [beta]-Ga2O3 composite substrates (Conference Presentation)

Jacob Leach, T. Hess, H. Splawn, Sukwon Choi, Craig McGray

Proceedings Volume 11281, 112810F (2020) https://doi.org/10.1117/12.2556295

Read Abstract +

Proceedings Article | 8 March 2019 Presentation

Halide vapor phase epitaxy of a- and b-Ga2O3 films (Conference Presentation)

Jacob Leach

Proceedings Volume 10919, 109190S (2019) https://doi.org/10.1117/12.2527567

KEYWORDS: Vapor phase epitaxy, Switching, Silicon, Silicon carbide, Carbon

Read Abstract +

Proceedings Article | 18 March 2016 Paper

Frequency conversion in free-standing periodically oriented gallium nitride

Christopher Brown, Steven Bowman, Jennifer Hite, Jaime Freitas, Francis Kub, Charles Eddy, Igor Vurgaftman, Jerry Meyer, Jacob Leach, Kevin Udwary

Proceedings Volume 9731, 97310E (2016) https://doi.org/10.1117/12.2213447

KEYWORDS: Gallium nitride, Frequency conversion, Nonlinear optics, Absorption, Optical semiconductors, Semiconductor materials, Semiconductors, Nonlinear frequency conversion, Gallium, Second-harmonic generation, Nonlinear crystals, Scanning electron microscopy, Metalorganic chemical vapor deposition, Harmonic generation, Infrared radiation, Crystals

Read Abstract +

Proceedings Article | 22 May 2015 Paper

Synthesis of two-dimensional materials for beyond graphene devices

Kehao Zhang, Sarah Eichfeld, Jacob Leach, Bob Metzger, Yu-Chuan Lin, Keith Evans, Joshua Robinson

Proceedings Volume 9467, 94670O (2015) https://doi.org/10.1117/12.2177985

KEYWORDS: Graphene, Metalorganic chemical vapor deposition, Chemical vapor deposition, Sapphire, Raman spectroscopy, Atomic force microscopy, Crystals, Scanning electron microscopy, Temperature metrology, Tungsten

Read Abstract +

Proceedings Article | 22 May 2015 Paper

Two-dimensional materials for low power and high frequency devices

Brian Bersch, Yu-Chuan Lin, Kehao Zhang, Sarah Eichfeld, Jacob Leach, Robert Metzger, Keith Evans, Joshua Robinson

Proceedings Volume 9467, 94670T (2015) https://doi.org/10.1117/12.2177986

KEYWORDS: Atomic layer deposition, Graphene, Dielectrics, Heterojunctions, Transistors, Transition metals, Field effect transistors, Oxides, Electronics, Semiconductors

Read Abstract +

Proceedings Article | 8 March 2014 Paper

Large-area bow-free n+ GaN templates by HVPE for LEDs

J. Leach, Y. Shishkin, K. Udwary, E. Preble, K. Evans

Proceedings Volume 8986, 898602 (2014) https://doi.org/10.1117/12.2041642

KEYWORDS: Gallium nitride, Semiconducting wafers, Polishing, Light emitting diodes, Sapphire, Surface finishing, Epitaxy, Metalorganic chemical vapor deposition, Manufacturing, Crystals

Read Abstract +

Proceedings Article | 8 March 2014 Paper

Polarized time-resolved photoluminescence measurements of m-plane AlGaN/GaN MQWs

Daniel Rosales, B. Gil, T. Bretagnon, F. Zhang, S. Okur, M. Monavarian, N. Izioumskaia, V. Avrutin, Ü. Özgür, H. Morkoç, J. Leach

Proceedings Volume 8986, 89860L (2014) https://doi.org/10.1117/12.2036984

KEYWORDS: Luminescence, Quantum wells, Polarization, Gallium nitride, Temperature metrology, Excitons, Anisotropy, Picosecond phenomena, 3D modeling, Tantalum

Read Abstract +

Proceedings Article | 4 March 2013 Paper

Recombination dynamics in non-polar m-plane GaN investigated by time- and polarization-resolved photoluminescence

Serdal Okur, Kestutis Jarašiūnas, Shopan din Ahmad Hafiz, Jacob Leach, Tania Paskova, Vitaliy Avrutin, Hadis Morkoç, Ümit Özgür

Proceedings Volume 8625, 86252D (2013) https://doi.org/10.1117/12.2005252

KEYWORDS: Excitons, Polarization, Gallium nitride, Luminescence, Temperature metrology, Spectroscopy, Dual energy x-ray absorptiometry, Polarizers, Continuous wave operation, Time resolved spectroscopy

Read Abstract +

Proceedings Article | 4 March 2013 Paper

High voltage bulk GaN-based photoconductive switches for pulsed power applications

J. Leach, R. Metzger, E. Preble, K. Evans

Proceedings Volume 8625, 86251Z (2013) https://doi.org/10.1117/12.2005548

KEYWORDS: Switches, Gallium nitride, Resistance, Pulsed laser operation, Pulsed power, Absorption, Semiconductors, Resistors, Switching, Capacitors

Read Abstract +

Proceedings Article | 28 February 2012 Paper

Recombination and diffusion processes in polar and nonpolar bulk GaN investigated by time-resolved photoluminescence and nonlinear optical techniques

Kęstutis Jarašiūnas, Patrik Ščajev, Saulius Nargelas, Ramūnas Aleksiejūnas, Jacob Leach, Tania Paskova, Serdal Okur, Ümit Özgür, Hadis Morkoç

Proceedings Volume 8262, 82620G (2012) https://doi.org/10.1117/12.906303

KEYWORDS: Diffusion, Gallium nitride, Carrier dynamics, Luminescence, Excitons, Picosecond phenomena, Interfaces, Crystals, Transient nonlinear optics, Absorption

Read Abstract +

Proceedings Article | 4 March 2011 Paper

Low-frequency noise measurements of generation-recombination effect and field-assisted emission in AlGaN/GaN MOSHFETs and HFETs

Cemil Kayis, Jacob Leach, C. Y. Zhu, Mo Wu, X. Li, X. Yang, Veena Misra, Peter Handel, Ü. Özgür, H. Morkoç

Proceedings Volume 7939, 79392F (2011) https://doi.org/10.1117/12.875692

KEYWORDS: Dielectrics, Oxides, Temperature metrology, Interfaces, Gallium nitride, Scattering, Heterojunctions, Transistors, Interference (communication), Sapphire

Read Abstract +

Proceedings Article | 4 March 2011 Paper

Heterostructure designs for enhanced performance and reliability in GaN HFETs: camelback channels

J. Leach, M. Wu, H. Morkoç, M. Ramonas, A. Matulionis

Proceedings Volume 7939, 79391P (2011) https://doi.org/10.1117/12.877717

KEYWORDS: Phonons, Electrons, Gallium nitride, Heterojunctions, Plasmons, Reliability, Scattering, Picosecond phenomena, Field effect transistors, Channel projecting optics

Read Abstract +

Proceedings Article | 4 March 2011 Paper

Deep inductively coupled plasma etching of ELO-GaN grown with high fill factor

Haiyong Gao, Jaesoong Lee, Xianfeng Ni, Jacob Leach, Ümit Özgür, Hadis Morkoç

Proceedings Volume 7939, 793920 (2011) https://doi.org/10.1117/12.876870

KEYWORDS: Etching, Gallium nitride, Scanning electron microscopy, Epitaxial lateral overgrowth, Dielectrics, Plasma etching, Silica, Metalorganic chemical vapor deposition, Atomic force microscopy, Nickel

Read Abstract +

Proceedings Article | 4 March 2011 Paper

Effect of substrate offcut on AlGaN/GaN HFET structures on bulk GaN substrates

J. Leach, N. Biswas, T. Paskova, E. Preble, K. Evans, M. Wu, X. Ni, X. Li, Ü. Özgür, H. Morkoç

Proceedings Volume 7939, 79390E (2011) https://doi.org/10.1117/12.875755

KEYWORDS: Gallium nitride, Heterojunctions, Aluminum, Resistance, Semiconducting wafers, Sapphire, Crystals, Polishing, Epitaxy, X-ray diffraction

Read Abstract +

Proceedings Article | 17 March 2010 Paper

Measurements of gate lag in high-quality nearly lattice matched InAlN/AlN/GaN HFET structures

J. Leach, M. Wu, X. Ni, X. Li, Ü. Özgür, H. Morkoç

Proceedings Volume 7602, 76020O (2010) https://doi.org/10.1117/12.843700

KEYWORDS: Gallium nitride, Field effect transistors, Polarization, Binary data, Sapphire, Heterojunctions, Aluminum nitride, Indium nitride, Interfaces, Solids

Read Abstract +

Proceedings Article | 12 March 2010 Paper

1/f noise: a window to HFET stability

Peter Handel, Taher Sherif, Cemil Kayis, Jacob Leach, Congyong Zhu, Hadis Morkoç

Proceedings Volume 7602, 76020M (2010) https://doi.org/10.1117/12.842948

KEYWORDS: Phonons, Gallium nitride, Field effect transistors, Polarization, Plasma, Phase measurement, Reliability, Plasmons, Quantum physics, Resistance

Read Abstract +

Proceedings Article | 20 February 2009 Paper

Transient current spectroscopy of lattice matched InAlN/AlN/GaN HFETs for identification of traps resulting in gate lag

J. Leach, Q. Fan, J. Xie, M. Wu, Ü. Özgür, H. Morkoç

Proceedings Volume 7216, 72162L (2009) https://doi.org/10.1117/12.809795

KEYWORDS: Field effect transistors, Aluminum nitride, Gallium nitride, Measurement devices, Reliability, Spectroscopes, Spectroscopy, Temperature metrology, Heterojunctions, Heart

Read Abstract +

Proceedings Article | 20 February 2009 Paper

Two dimensional electron gas in GaN heterojunction field effect transistors structures with AlN spacer

Qian Fan, Jacob Leach, Jinqiao Xie, Umit Ozgur, Hadis Morkoç, L. Zhou, D. Smith

Proceedings Volume 7216, 72162N (2009) https://doi.org/10.1117/12.811678

KEYWORDS: Aluminum nitride, Gallium nitride, Heterojunctions, Polarization, Field effect transistors, Data modeling, Metals, Scanning transmission electron microscopy, Nickel, Fluctuations and noise

Read Abstract +

Proceedings Article | 20 February 2009 Paper

Electrical defects in AlGaN and InAlN

D. Johnstone, Jacob Leach, Vladimir Kovalskii, Qian Fan, Jingqiao Xie, Hadis Morkoç

Proceedings Volume 7216, 72162R (2009) https://doi.org/10.1117/12.815020

KEYWORDS: Gallium nitride, Capacitance, Temperature metrology, Spectroscopes, Aluminum, Diodes, Semiconductors, Heterojunctions, Spectroscopy, Metalorganic chemical vapor deposition

Read Abstract +

Proceedings Article | 19 February 2009 Paper

GaN-based vertical cavities on highly reflective and crack-free nitride distributed Bragg reflectors

X. Ni, R. Shimada, T. Kang, J. Leach, Ü. Özgür, H. Morkoç

Proceedings Volume 7216, 72162F (2009) https://doi.org/10.1117/12.807902

KEYWORDS: Reflectivity, Gallium nitride, Semiconducting wafers, Distributed Bragg reflectors, Vertical cavity surface emitting lasers, Aluminum nitride, Silica, Scanning electron microscopy, Aluminum, Photomasks

Read Abstract +

Proceedings Article | 28 February 2008 Paper

Comparison of various gate dielectrics on the performance of AlGaN/GaN HFETS

Qian Fan, Jacob Leach, Mo Wu, Bo Xiao, Xing Gu, Hadis Morkoç, Peter Handel

Proceedings Volume 6894, 689426 (2008) https://doi.org/10.1117/12.763688

KEYWORDS: Dielectrics, Ferroelectric materials, Silica, Zirconium dioxide, Transistors, Heterojunctions, Gallium nitride, Plasma enhanced chemical vapor deposition, Capacitance, Crystals

Read Abstract +

Proceedings Article | 15 February 2008 Paper

Optical properties of polar, nonpolar, and semipolar InGaN/GaN multiple quantum wells on sapphire

X. Ni, R. Shimada, J. Leach, J. Xie, Ü. Özgür, H. Morkoç

Proceedings Volume 6894, 689428 (2008) https://doi.org/10.1117/12.763260

KEYWORDS: Gallium nitride, Quantum wells, Epitaxial lateral overgrowth, Polarization, Sapphire, Optical properties, Quantum efficiency, Metalorganic chemical vapor deposition, Luminescence, Scanning electron microscopy

Read Abstract +

The polarization fields in the c-axis-oriented hexagonal GaN system cause spatial separation of electrons and holes in quantum wells, reducing the quantum efficiency, and resulting in a red shift of the emission as well as a blue shift with increasing injected carrier density. In this paper, we report on the growth and optical characterization of InGaN/GaN multiple quantum wells (MQWs) on nonpolar (112¯0) a- and polar (0001) c-planes, as well as two semipolar planes, (112¯2) and (11¯01) of GaN. There are two kinds of a-plane used in this study. One of the (112¯0) a-planes was obtained on (11¯00) m-plane sapphire substrates during the epitaxial lateral overgrowth (ELO) of (112¯2) oriented semipolar GaN films, while the other one was planar a-plane GaN which was grown on (11¯01) r-plane sapphire substrates. The semipolar (112¯2) and (11¯01) planes were obtained as sidewall facets during the ELO of c-plane GaN with the mask stripes aligned along the GaN m-axis and a-axis, respectively. InGaN/GaN multiple quantum wells (MQWs) with a nominal well thickness of 4 nm and a barrier thickness of 8 nm were grown on these five GaN samples by metalorganic chemical vapor deposition. Excitation power dependent photoluminescence (PL) measurements were carried out on these quantum well structures to study the effect of polarization-induced electric field on the band-edge emission. The quantum-well emission energy from the two a-plane MQWs showed zero shift, compared to a 74 meV blue shift for the c-plane MQWs when the excitation power was increased from 1.3 mW to 37.0 mW. The semipolar (112¯2) showed a blue shift of 35 meV with increased excitation power, suggesting reduced polarization compared to that of c-plane. No quantum-well emission could be observed for the MQWs on (11¯01) semipolar planes. The shift in the quantum-well emission energy was attributed to the change of the screening effect of photon-generated carriers in the quantum wells at different excitation powers. For exact notation please see manuscript

Proceedings Article | 15 February 2008 Paper

AlxIn1-xN/GaN heterostructure field effect transistors

J. Xie, X. Ni, M. Wu, J. Leach, Ü. Özgür, H. Morkoç

Proceedings Volume 6894, 68941R (2008) https://doi.org/10.1117/12.771297

KEYWORDS: Aluminum nitride, Gallium nitride, Heterojunctions, Aluminum, Indium, Field effect transistors, Polarization, Metalorganic chemical vapor deposition, Temperature metrology, Scattering

Read Abstract +

Proceedings Article | 15 February 2008 Paper

Evolution of surface morphology of polar and nonpolar GaN thin films during photoelectrochemical etching

J. Leach, Ü. Özgür, X. Ni, J. Xie, H. Morkoç

Proceedings Volume 6894, 689425 (2008) https://doi.org/10.1117/12.762383

KEYWORDS: Etching, Gallium nitride, Epitaxial lateral overgrowth, Scanning electron microscopy, Thin films, Nanostructures, Transmission electron microscopy, Ions, Oxides, Active optics

Read Abstract +

Proceedings Article | 20 February 2007 Paper

Carrier relaxation and stimulated emission in ZnO nanorods grown by catalyst-assisted vapor transport on various substrates

V. Avrutin, Ü. Özgür, N. Izyumskaya, S. Chevtchenko, J. Leach, J. Moore, A. Baski, C. Litton, H. Everitt, K. Tsen, M. Abouzaid, P. Ruterana, H. Morkoç

Proceedings Volume 6474, 64741M (2007) https://doi.org/10.1117/12.708835

KEYWORDS: Zinc oxide, Silicon, Near field scanning optical microscopy, Atomic force microscopy, Luminescence, Transmission electron microscopy, Gallium nitride, Raman spectroscopy, Nanostructures, Nanorods

Read Abstract +

Showing 5 of 26 publications

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Keywords/Phrases

Search In:

Publication Years