Zachary Lochner
Zachary M. Lochner, Ph.D.
Senior Associate
Electrical Engineering & Computer Science
  • New York

Dr. Lochner has extensive experience performing root-cause failure analysis of electrical systems and consumer electronics such as semiconductor manufacturing equipment, medical devices, surge protectors, microwave ovens, washing machines, and mobile phones. This includes technical analysis of specific components such as integrated circuits, flash memory, printed circuit boards, LCDs, and LEDs. Dr. Lochner has provided scientific consultation to litigation matters involving intellectual property for microelectronic devices, class-action lawsuits involving household appliances, insurance claims for large electrical infrastructure and fire investigations. He has applied an in depth knowledge of relevant electrical codes and standards including NFPA, NEC, UL, and NEMA.

Dr. Lochner received his M.S. and Ph.D. in Electrical Engineering at the Georgia Institute of Technology. His PhD dissertation focused on semiconductor crystal growth as well as design, fabrication and characterization of heterojunction bipolar transistors, laser diodes, light emitting diodes, and heterojunction field-effect transistors in the III-nitride material system. He has expertise with the following semiconductor tools: metalorganic chemical vapor deposition (MOCVD), atomic force microscopy, X-ray diffraction, Hall effect measurement, photoluminescence, electroluminescence, capacitance-voltage measurement, impedance spectroscopy, ellipsometry, resistivity measurements, reflectometry, profilometry, scanning electron microscopy, secondary ion mass spectrometry, photolithography and electron beam lithography.

During his studies he interned at Robert Bosch GmbH in Stuttgart, Germany where he worked on the characterization of dye sensitized solar cells. He also interned at the Electricity Generating Authority of Thailand near Chang Mai working on power plant system control and failure simulations.

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Electrical and Computer Engineering, Georgia Institute of Technology (Georgia Tech), 2013
  • M.S., Electrical and Computer Engineering, Georgia Institute of Technology (Georgia Tech), 2010
  • B.S., Electrical Engineering, State University of New York, Buffalo, 2007, summa cum laude

Publications

Liu Y-S, Kao T-T, Satter M, Lochner Z, Shen S-C, Detchprohm T, Yoder PD, Dupuis RD, Ryou J-H, Fischer AM, Wei YO, Xie H, Ponce FA. Inverse-tapered p-waveguide for vertical hole transport in high-[Al] AlGaN Emitters. IEEE Photonics Technology Letters 2015; 27:1768–1771.

Kim J, Lochner Z, Ji M-H, Choi S, Kim HJ, Kim JS, Dupuis RD, Fischer AM, Juday R, Huang Y, Li T, Huang JY, Ponce FA, Ryou J-H. Origins of unintentional incorporation of gallium in InAlN layers during epitaxial growth, part II: Effects of underlying layers and growth chamber conditions. Journal of Crystal Growth 2014; 388:143–149.

Choi S, Kim H.J., Lochner Z, Kim J, Dupuis RD, Fischer AM, Juday R, Huang Y, Li T, Huang JY, Ponce F.A., Ryou J-H. Origins of unintentional incorporation of gallium in AlInN layers during epitaxial growth, part I: Growth of AlInN on AlN and effects of prior coating. Journal of Crystal Growth 2014; 388:137–142.

Satter MM, Lochner Z, Kao T-T, Liu Y-S, Li X-H, Shen S-C, Dupuis RD, Yoder PD. AlGaN-based vertical injection laser diodes using inverse tapered p-waveguide for efficient hole transport. IEEE Journal of Quantum Electronics 2014; 50(3):166–173.

Liu Y-S, Kao T-T, Satter Md M, Lochner Z, Li X-H, Shen S-C, Yoder PD, Detchprohm T, Dupuis RD, Wei Y, Xie H, Fischer A, Ponce FA. Optically pumped deep-ultraviolet AlGaN multi-quantum-well lasers grown by metalorganic chemical vapor deposition. Proceedings, SPIE 2014; 9002, 90020H.

Liu Y-S, Lochner Z, Kao T-T, Satter Md M, Li X-H, Ryou J-H, Shen S-C, Yoder PD, Detchprohm T, Dupuis RD, Wei Y, Xie H, Fischer A, Ponce F. Optically pumped AlGaN quantum-well lasers at sub-250 nm grown by MOCVD on AlN substrates. Physica Status Solidi C 2014; 11:258–260.

Satter, Md. M., Liu Y-S, Kao T-T, Lochner Z, Li X, Ryou J-H, Shen S-C, Detchprohm T, Dupuis RD, Yoder PD. Theoretical analysis of strategies for improving p-type conductivity in wurtzite III-nitride devices for high-power opto- and microelectronic applications. Physica Status Solidi C 2014; 11:828–831.

Kao T-T, Liu Y-S, Mahbub Satter Md, Li X-H, Lochner Z, Yoder PD, Theeradetch D, Dupuis RD, Shen S-C, Ryou J-H, Fischer AM, Wei Y, Xie H, Ponce FA. Sub-250 nm low-threshold deep-ultraviolet AlGaN-based heterostructure laser employing HfO2/SiO2 dielectric mirrors. Applied Physics Letters 2013; 103, 211103.

Satter MM, Lochner Z, Ryou JH, Shen SC, Dupuis RD, Yoder PD. AlGaN-based lateral currentinjection laser diodes using regrown ohmic contacts. IEEE Photonics Technology Letters 2013; 25:313–316.

Li T, Wei QY, Fischer AM, Huang JY, Huang YU, Ponce FA, Liu JP, Lochner Z, Ryou JH, Dupuis RD. The effect of InGaN underlayers on the electronic and optical properties of InGaN/GaN quantum wells. Applied Physics Letters 2013; 102, 041115.

Lochner Z, Kao T-T, Liu Y-S, Li X-H, Mahbub Satter M, Shen S-C, Yoder PD, Ryou J-H, Dupuis RD, Wei Y, Xie H, Fischer A, Ponce FA. Stimulated emission at 257 nm from optically-pumped AlGaN/AlN heterostructure on AlN substrate. Physica Status Solidi A 2013; 210:1768–1770.

Lochner Z, Kao T-T, Liu Y-S, Li X-H, Satter MM, Shen S-C, Yoder PD, Ryou J-H, Dupuis RD, Wei Y, Xie H, Fischer A, Ponce FA. Deep-ultraviolet lasing at 243 nm from Photo-pumped AlGaN/AlN heterostructure on AlN substrate. Applied Physics Letters 2013; 102:101110.

Lochner Z, Kao T-T, Liu Y-S, Li X-H, Satter MM, Shen S-C, Yoder PD, Ryou J-H, Dupuis RD, Wei Y, Xie H, Fischer A, Ponce FA. Room-temperature optically pumped AlGaN-AlN multiple-quantum-well lasers operating at <260 nm grown by metalorganic chemical vapor deposition. Proceedings, SPIE 2013; 8625:862519.

Lochner Z, Hee Jin Kim, Yi-Che Lee, Yun Zhang, Suk Choi, Shen S-C, P. Doug Yoder, Jae-Hyun Ryou, Dupuis RD. NpN-GaN/InxGa1-xN/GaN heterojunction bipolar transistor on free-standing GaN substrate. Applied Physics Letters 2011; 99, 193501. 

Lochner Z, Kim HJ, Choi S, Lee Y-C, Zhang Y, Shen S-C, Ryou J-H, Russell D, Dupuis RD. Growth and characterization of NpN heterojunction bipolar transistors with In0.03Ga0.97N and In0.05Ga0.95N bases. Journal of Crystal Growth 2011; 315:278–282.

Kim HJ, Lee YC, Zhang Y, Ryou JH. III-nitride heterojunction field-effect transistors and heterojunction bipolar transistors for next-generation power electronics. ECS Transactions 2011; 41(8):73–85.

Satter Md, Lochner Z, Ryou J-H, Shen S-C, Dupuis RD, Yoder PD. Polarization matching in AlGaN-based multiple-quantum-well deep ultraviolet laser diodes on AlN substrates using quaternary AlInGaN barriers. Journal of Lightwave Technology 2012; 30:3017–3025.

Kim S, Kim HJ, Choi S, Lochner Z, Ryou J-H, Dupuis RD, Kim H. Carrier transport properties of Mg-doped InAlN films. Electronics Letters 2012; 48:1306–1308.

Satter Md M, Kim HJ, Lochner Z, Ryou J-H, Shen -C, Dupuis RD, Yoder PD. Design and analysis of 250nm AlInN laser diodes on AlN substrates using tapered electron blocking layers. IEEE Journal of Quantum Electronics 2012; 48(5): 703–711.

Lee Y-C, Zhang Y, Lochner ZM, Kim H-J, Ryou J-H, Dupuis RD, Shen S-C. GaN/InGaN heterojunction bipolar transistors with ultra-high d.c. power density (>3 MW/cm2). Physica Status Solidi A 2012; 209:497–500.

Abid M, Moudakir T, Orsal G, Gautier S, En Naciri A, Djebbour Z, Ryou J-H, Patriarche G, Largeau L, Kim HJ, Lochner Z, Pantzas K, Alamarguy D, Jomard F, Dupuis RD, Salvestrini J-P, Voss PL, Ougazzaden A. Distributed Bragg reflectors based on diluted boron-based BAlN alloys for deep ultraviolet optoelectronic applications. Applied Physics Letters 2012; 100, 051101.

Yoder PD, Ryou JH. GaN/InGaN heterojunction bipolar transistors with fT > 5 GHz. IEEE Electron Device Letters 2011; 32(8):1065–1067.

Zhang Y, Lee YC, Lochner Z, Kim HJ, Choi S, Ryou JH, Dupuis RD, Shen SC. High-performance GaN/InGaN double heterojunction bipolar transistors with power density >240 kW/cm2. Physica Status Solidi (c) 2011; 8 (7–8):2451–2453.

Zhang Y, Liu JP, Kao T-T, Kim S, Lee Y-C, Lochner Z, Ryou J-H, Yoder PD, Dupuis RD, Shen S-C. Performance enhancement of InGaN-based laser diodes using a step graded AlGaN Electron Blocking Layer. International Journal of High Speed Electronics and Systems 2011; 20:515–520.

Zhang Y, Kao T-T, Liu J, Lochner Z, Kim S-S, Ryou J-H, Dupuis RD, Shen S-C. Effects of a step-graded AlxGa1-xN electron blocking layer in InGaN-based laser diodes. Journal of Applied Physics 2011; 109(8):083115-1–5.

Liu J, Zhang Y, Lochner Z, Kim S-S, Kim H, Ryou J-H, Shen S-C, Yoder D, Dupuis RD, Wei QY, Sun KW, Fischer AM, Ponce FA. Performance characteristics of InAlGaN laser diodes depending on electron blocking layer and waveguiding layer design grown by metalorganic chemical vapor deposition. Journal of Crystal Growth 2011; 315:272–277.

Xu S, Xu C, Liu Y, Hu Y, Yang R, Yang Q, Ryou J-H, Kim HJ, Lochner Z, Choi S, Dupuis R, Wang ZL. Ordered nanowire array blue/near-UV light emitting diodes. Advanced Materials 2010; 22(42): 4749–4753.

Liu JP, Zhang Y, Lochner Z, Kim S-S, Kim H, Ryou J-H, Shen S-C, Yoder PD, Dupuis RD, Wei Q, Sun K, Fischer A, Ponce F. Performance improvement of InGaN-based laser diodes by epitaxial layer structure design. Proceedings, SPIE 2010; 7602: 760219.

Choi S, Kim HJ, Lochner Z, Zhang Y, Lee YC, Shen SC, Ryou JH, Dupuis RD. Threshold voltage change by InxAl1-xN in InAlN/GaN heterostructure field-effect transistors for depletion- and enhancement mode operations. Applied Physics Letters 2010; 96(24):243506-1-3.

Lee YC, Zhang Y, Kim H-J, Choi S, Lochner Z, Dupuis RD, Ryou JH, Shen SC. High-current-gain GaN/InGaN double heterojunction bipolar transistors. IEEE Transaction on Electron Devices 2010; 57(11):2964–2969.

Ryou JH, Yoder PD, Jianping L, Lochner Z, Suk HC, Jin KH, Dupuis RD. Control of quantum-confined stark effect in InGaN-based quantum wells. IEEE Journal of Selected Topics in Quantum Electronics 2009; 15(4):1080–1091.

Liu JP, Limb J, Lochner Z, Yoo D, Ryou JH, Dupuis RD. Green light-emitting diodes with p-InGaN:Mg grown on c-plane sapphire and GaN substrates. Physica Status Solidi (a) 2009; 204:750–753.

Ougazzaden A, Gautier S, Moudakir T, Djebbour Z, Lochner Z, Choi S, Kim HJ, Ryou JH, Dupuis RD, Sirenko AA. Bandgap bowing in BGaN thin films. Applied Physics Letters 2008; 93:083118.

Dupuis RD, Ryou JH, Shen SC, Yoder PD, Zhang Y, Kim HJ, Choi S, Lochner Z. Growth and fabrication of high-performance GaN-based ultraviolet avalanche photodiodes. Journal of Crystal Growth 2008; 310:5217–5222.

Ryou JH, Limb J, Lee W, Liu JP, Lochner Z, Yoo D, Dupuis RD. Effect of silicon doping in the quantum well barriers on the electrical and optical properties of visible green light emitting diodes. IEEE Photonics Technology Letters 2008; 20:1769–1771.

Liu J, Ryou J-H, Lochner Z, Limb J, Yoo D, Dupuis RD, Zhihao Wu, Fischer AM, Ponce FA. Surface morphology control of green LEDs with p-InGaN layers grown by metalorganic chemical vapor deposition. Journal of Crystal Growth 2008; 310:5166–5169.

Conference Presentations


Dupuis RD, Lochner Z, Kao T-T, Liu Y-S, Li X-H, Satter MM, Shen C, Yoder PD, Ryou J-H, Wei Y, Xie H, Fischer A, Ponce FA. Room-temperature optically pumped AlGaN-AlN multiple-quantum-well lasers operating at <260 nm grown by MOCVD. SPIE Photonics West 2013, San Francisco, CA, February 2013.

Lochner Z, Xiaohang Li, Kim HJ, Zhang Y, Choi S, Lee Y-C, Ryou J-H, Shen S-C, Dupuis RD. High power and RF characterizations of III-nitride heterojunction bipolar transistors on free standing GaN substrates. 54th Electronic Materials Conference (EMC 2012), Penn State University, PA, June 2012.

Dupuis RD, Shen S-C, Lochner ZM, Kim HJ, Lee Y-C, Zhang Y, Ryou J-H. III-nitride heterojunction field-effect transistors and heterojunction bipolar transistors for next-generation power electronics. (E10-2171), 220th Electrochemical Society (ECS) Meeting: GaN and SiC Power Technologies, Boston, MA, October 2011.

Lee Y-C, Zhang Y, Lochner ZM, Kim HJ, Ryou J-H, Dupuis RD, Shen S-C. Ultra-high-power characteristics of GaN/InGaN heterojunction bipolar transistors” (I.1), 9th International Conference on Nitride Semiconductors (ICNS-9), Glasgow, UK, July 2011.

Lochner Z, Kim HJ, Zhang Y, Lee YC, Choi S, Shen SC, Yoder PD, Ryou JH, Dupuis RD. Epitaxial growth and characterization of npn-GaN/InGaN/GaN heterojunction bipolar transistors on foreign and native substrates. 18th American Conference on Crystal Growth and Epitaxy (ACCGE-18)/15th US Biennial Workshop on Organometallic Vapor Phase Epitaxy (OMVPE-15), Monterey, CA, July–August 2011.

Lochner Z, Kim HJ, Zhang Y, Choi S, Lee Y-C, Ryou J-H, Shen S-C, Dupuis RD. Growth and characterization of npn-GaN/InGaN/GaN Double-heterojunction bipolar transistors on a free-standing GaN substrate. (J10), 53rd Electronic Materials Conference (EMC 2011), Santa Barbara, CA, June 2011.

Lochner Z, Kim HJ, Choi S, Lee Y-C, Zhang Y, Ryou J-H, Shen S-C, Dupuis RD. Growth and characterization of InxGa1-xN/GaN heterojunction bipolar transistors. (IP1.14), International Workshop on Nitride Semiconductors (IWN 2010), Tampa, FL, September 2010.

Lochner Z, Kim HJ, Choi S, Lee Y-C, Zhang Y, Ryou J-H, Shen S-C, Dupuis RD. Growth and characterization of InGaN heterojunction bipolar transistors. (L9), 52nd Electronic Materials Conference (EMC 2010), Notre Dame, IN, June 2010.

Lochner Z, Kim HJ, Choi S, Lee Y-C, Zhang Y, Ryou J-H, Shen S-C, Dupuis RD. III-N-based heterojunction bipolar transistors having InxGa1-xN base with varied indium compositions. 15th International Conference of Metalorganic Vapor Phase Epitaxy (ICMOVPE XV), Incline Village, NV, May 2010.


Prior Experience

Research Assistant, Georgia Institute of Technology, 2007–2013

Physical and Chemical Technology Advanced Research Intern, Robert Bosch GmbH, 2009

Assistant Course Builder, SUNY Buffalo, 2006-2007

Simulator Section Engineering Intern, Electricity Generating Authority of Thailand, 2006

Professional Affiliations

IEEE (member)

Project Experience

Thin Film Transistor Liquid Crystal Displays

  • Patent analysis relating to TFT LCDs
  • Validity and prior art investigation of patents related to TFT LCDs

Consumer Electronics – Smartphone

  • Technical analysis on firmware code 
  • Patent infringement analysis of accused smartphone products
  • Root cause failure analysis on specific components such as LEDs, integrated circuits, and batteries

Consumer Electronics – Product Support


  • Performed user studies for electronic products
  • Assembled technology review of components for use in new products
  • Conducted due diligence investigation for semiconductor manufacturing optimization technology

Wi-Fi Router

  • Technical analysis on MIMO data streams 
  • Infringement analysis and product testing of routers and antennae

Microelectronic Flash Memory

  • Patent validity and infringement analysis of flash memory products
  • Reverse engineering SEM/TEM image analysis of accused products
  • Technical analysis of GDS design files, circuit schematics, and logic control of accused products
Hurricane Damage Assessment

  • On-site inspection and documentation of damages
  • Scope-of-loss analysis to mechanical, electrical and plumbing (MEP) systems
  • Investigated the condition of electrical equipment exposed to brackish water

Failure Analysis

  • Root cause analysis of microwave oven failure modes
  • Technical analysis of telecommunication power supply ground detect circuit fault
  • Root cause analysis of medical device failure
  • Investigation of failure in cyclotron used for the production of medical isotopes
  • Investigation of surge protector failure modes
  • Root cause analysis of washing machine electronics failure
  • Root cause analysis of warehouse fire involving automated systems

E-Discovery – Document Translation
  • Developed a procedure to automate the translation of over ~25,000 documents from Japanese to English while maintaining original document formatting for document discovery in litigation

CREDENTIALS & PROFESSIONAL HONORS

  • Ph.D., Electrical and Computer Engineering, Georgia Institute of Technology (Georgia Tech), 2013
  • M.S., Electrical and Computer Engineering, Georgia Institute of Technology (Georgia Tech), 2010
  • B.S., Electrical Engineering, State University of New York, Buffalo, 2007, summa cum laude