Fabrication and Characterization of High Power Gallium Nitride Devices and Material
Gallium Nitride (GaN) Schottky diodes were studied to determine their effectiveness in electronic devices. Research of Schottky barriers and Ohmic contacts are being investigated to develop high quality GaN contacts that are necessary for efficient electronic devices. The Ohmic and Schottky contacts were fabricated on p-type GaN samples. Schottky contacts will be fabricated using aluminum (Al) and titanium/gold (Ti/Au) metals. Matlab simulations of GaN-based Ohmic contacts and Schottky barriers will be analyzed to provide a better understanding of the material's characteristics and how different factors affected the contacts to the semiconductor. Physical test will include I-V and C-V measurements and characterizations using a HP4155. Fabrication of GaN Ohmic contacts was successful. However the Schottky contacts were not suitable and exhibited Ohmic characteristics rather than Schottky characteristics. The experiments still did not show conclusive understanding of the formation of Ohmic contacts because only a percentage of the fabricated contacts exhibited Ohmic behavior. In addition, the Schottky contacts could have been contaminated in the fabrication process due to unclean surfaces or some other interfacial processes. The inability to create the desired contacts may be a result of the lack of understanding of the chemical and electrical reactions of GaN and metal contacts.
School:
University of Illinois at Urbana-Champaign
Department:
Electrical Engineering
Research Advisor:
Kevin Kim
Department of Research Advisor:
Electrical and Computer Engineering
Year of Publication:
2003