PEER Project Descriptions: Summer 2004
1.
High Temperature Dielectrics for Wide Bandgap Power Devices
Prof. R. D. Vispute, (Physics, UMCP)
Our current research activites under the PEER are focused on wide bandgap (WBG) semiconductors (particularly SiC) and related materials, their processing, and the successful passivation of WBG power electronics devices, including diodes and transistors, using alternative dielectric films such as AlN. This work involves understanding how to deposit these dielectric films and analyze their quality using various diagnostic tools.
2.
Growth, Characterization, and Processing of Materials for Improving the
P-N Junction Characteristics in Wide Bandgap Semiconductors
Prof. T. Venkatesan and Dr. K. Jones (ARL)
Wide bandgap semiconductors such as SiC and GaN have many potential high power, high temperature applications, but their implementation has been limited, in part, by an ability to obtain isolated, high quality p-n junctions. This is due to the higher leakage currents and lower breakdown voltages produced by defects created by the ion implantation process used to create them. We will continue exploring ways to better define these defects so we can better control their negative effects, and we will explore replacing the ion implantation process with selective area growth by developing a high temperature cap that can withstand the high temperature corrosive environment of the growth process. This will be done by growing cap material using pulsed laser deposition (PLD), characterizing it, and learning how to etch it selectively.
3.
Modeling, Characterization, and Design of Wide Bandgap MOSFETs and MISFETs for High-Temperature/High-Power Applications
Prof. N. Goldsman
This project is investigating the design of new high-temperature /high-power electronics based on silicon carbide (SiC), a material which shows great promise for use in power electronics. Power-conversion/motor-control systems that can operate at high power densities and high temperatures are being designed. To control these systems, we will investigate the design and development of high temperature voltage-controlled electronics. As was demonstrated in industry for room-temperature applications, the optimal component for electronic control circuits was the silicon MOSFET. For high temperature we intend to build on this strategy by developing SiC MOSFETs. SiC is unique in the sense that it appears to be the only semiconductors capable of operating at high temperatures, which can also be used as a basis for MOSFET fabrication.
4.
Wide Band Gap Heterostructures of Oxides and Nitrates for Fabrication
of Advanced MEMS
Prof. R. D. Vispute, (Physics, UMCP)
Micro- and nanoelectromechanical systems (MEMS/NEMS) are promising for a variety of applications in advanced military and commercial systems operating in harsh environments such as high temperatures, intense vibrations, erosive flow, corrosive media, and aerospace. This project, based on joint efforts between UMD and ARL, will investigate thin film growth of AlN and/or MgZnO composite structures for MEMS and NEMS device applications, fabrication and characterization of high frequency resonant MEMS and NEMS test devices, an investigation of novel oxide films as improved structural layers, and investigation of loss mechanisms and their relation to material properties and device quality factor. Specific goals include pulsed laser deposition of AlN and/or MgZnO piezoelectric films integrated with appropriate structural and conductive layers on silicon and/or SiC substrates, and the design, fabrication, and testing of bandpass and notch filters based on micro- and nanoscale electromechanical resonator technology.