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Vamsi_Thesis.pdf (3.28 MB)
ETD Abstract Container
Abstract Header
Failure Analysis and High Temperature Characterization of Silicon Carbide Power MOSFETs
Author Info
Mulpuri, Vamsi
ORCID® Identifier
http://orcid.org/0000-0002-6288-6164
Permalink:
http://rave.ohiolink.edu/etdc/view?acc_num=akron151076214366849
Abstract Details
Year and Degree
2017, Master of Science in Engineering, University of Akron, Electrical Engineering.
Abstract
The reliability of power semiconductor switches is important when considering their vital role in power electronic converters for aerospace, railway, hybrid electric vehicle, and power system applications. Due to technology advancements in material sciences, power MOSFETs manufactured with wide band gap materials such as silicon carbide (SiC), gallium nitride (GaN) have been proposed as an alternative to existing silicon (Si) based MOSFETs and IGBTs. However, thorough reliability analysis should be performed before substituting SiC MOSFETs in the place of existing Si MOSFETs and IGBTs. Therefore, this thesis is carried out with an aim to evaluate the reliability of 1.2 kV SiC MOSFETs. In this study devices from semiconductor industry’s well-known manufacturers were evaluated. Accelerated life testing with repeated high pulse currents and high electric field stress were introduced in the experiments. The devices under test were also tested at elevated temperatures ranging from 25oC to 200oC as the SiC technology is renowned for high temperature applications. To carry out accelerated life testing a RC circuit was designed to repeatedly impose high pulse currents on the device. Care is taken in choosing the width of the pulse current such that the devices do not fail during the initial cycles of test. High temperature gate bias stress introducing high electric fields on SiC MOSFET gate is carried out to test the reliability of the device. Another experimental set up was designed for generating cyclic thermal stress. To identify the fault precursors, characterization of the device is conducted to observe the variations in electrical parameters such as on state resistance (RDS-on), threshold voltage (Vth), and gate to source leakage current (IGss) during and after aging conditions. Comparison of the fault precursors based on measurement complexity, sensitivity, and variation range are discussed. The characterization data was further used to determine the optimal aging precursor, and to analyze the root cause responsible for failure. Additionally, physical degradation analysis was carried out by using optical and scanning electron microscopes to observe the damage in bond wire, die attach, and aluminum metallization during stress conditions.
Committee
Choi Seundeog (Advisor)
Elbuluk Malik (Committee Member)
Toonen Ryan Christopher (Committee Member)
Pages
75 p.
Subject Headings
Engineering
Keywords
Silicon Carbide, Threshold Voltage, On state Resistance, Gate leakage Current, Gate Oxide, Metallization, Bond wire
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Refworks
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Citations
Mulpuri, V. (2017).
Failure Analysis and High Temperature Characterization of Silicon Carbide Power MOSFETs
[Master's thesis, University of Akron]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=akron151076214366849
APA Style (7th edition)
Mulpuri, Vamsi.
Failure Analysis and High Temperature Characterization of Silicon Carbide Power MOSFETs.
2017. University of Akron, Master's thesis.
OhioLINK Electronic Theses and Dissertations Center
, http://rave.ohiolink.edu/etdc/view?acc_num=akron151076214366849.
MLA Style (8th edition)
Mulpuri, Vamsi. "Failure Analysis and High Temperature Characterization of Silicon Carbide Power MOSFETs." Master's thesis, University of Akron, 2017. http://rave.ohiolink.edu/etdc/view?acc_num=akron151076214366849
Chicago Manual of Style (17th edition)
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Document number:
akron151076214366849
Download Count:
3,244
Copyright Info
© 2017, all rights reserved.
This open access ETD is published by University of Akron and OhioLINK.