Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


Theses of Sadia K. Monika.pdf (2.92 MB)

ETD Abstract Container

Abstract Header

III- Nitride Enhancement Mode Device

Monika, Sadia K
http://rave.ohiolink.edu/etdc/view?acc_num=osu1483535296785214

Abstract Details

2017, Master of Science, Ohio State University, Electrical and Computer Engineering.
GaN is a promising material for energy efficient high power switching applications due to its wide bandgap, and high critical field. However, for such applications normally off devices with high positive threshold voltage and low off-state current is desirable. In this thesis, first, we investigated the effects of different scattering mechanisms on the low field mobility of GaN MOSFET. We found that, unlike AlGaN/GaN HEMTs, where mobility is limited by phonon scattering, mobility in GaN MOSFET is limited by interface ionized impurity scattering and surface roughness scattering. Next, we investigate the effect of different process steps, namely, O2 plasma treatment, post dielectric anneal(PDA), and post metal anneal(PMA), on the threshold voltage, hysteresis, and mobility of Al2O3/GaN MOSFETs. Our study reveals that (a) lower hysteresis can be achieved by high temperature PDA in the presence of O2 plasma and PMA treatment, (b) large positive threshold voltage can be achieved with high temperature PDA and PMA treatment in absence of O2 plasma, and (c) high mobility can be achieved with only high temperature PMA treatment without O2 plasma and PDA treatment. Using our optimized process condition we achieved GaN MOSFET with 1.5 V threshold, 0.1 V hysteresis, 225 cm2V-1s-1 mobility, 67 mV/dec subthreshold swing, and 1010 on-off ratio. We also investigated the potential of AlON as a gate dielectric in GaN MOSFET. It is found that AlON can increase the threshold voltage in both HEMTs and MOSFET structures, most probably due to behavior of nitrogen atoms as acceptor like states. We demonstrate a 5 V, and 1.5 V shift in HEMT, and MOSFET structure using AlON as gate dielectric.
Rajan Siddharth, Dr. (Advisor)
Steven Ringel, Dr. (Committee Member)
72 p.
Electrical Engineering
GaN MOSFET, E-mode, GIT, Power Device, Positive threshold voltage, Mobility, Hysteresis, Subthreshold slope, Normally off device

Recommended Citations

Citations

  • Monika, S. K. (2017). III- Nitride Enhancement Mode Device [Master's thesis, Ohio State University]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=osu1483535296785214

    APA Style (7th edition)

  • Monika, Sadia. III- Nitride Enhancement Mode Device . 2017. Ohio State University, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=osu1483535296785214.

    MLA Style (8th edition)

  • Monika, Sadia. " III- Nitride Enhancement Mode Device ." Master's thesis, Ohio State University, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=osu1483535296785214

    Chicago Manual of Style (17th edition)

osu1483535296785214
784
© 2017, some rights reserved.Creative Commons License III- Nitride Enhancement Mode Device by Sadia K Monika is licensed under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License. Based on a work at etd.ohiolink.edu.
This open access ETD is published by The Ohio State University and OhioLINK.