Semiconductor transistors have shaped the modern world and have a multitude of applications including digital microelectronics and radio frequency (RF) electronics. Modern RF power amplifier modules employ compound semiconductors for their superior performance. However, the main disadvantage of compound semiconductor-based power amplifier transistors, specifically gallium nitride (GaN) high electron mobility transistors (HEMTs), is semiconductor defects which degrade electrical performance and can result in transistor reliability issues. This project will involve characterization and analysis of defects, also called traps, in GaN HEMTs. The student will learn multiple measurement techniques for characterizing traps and will study their effects on transistor performance. One such method is called drain current transient (DCT) measurements. During the 10-week program, the student will work with a graduate student mentor to measure DCT data for different GaN HEMT samples. Furthermore, the student will study the ambient temperature effects on the traps and will extract an Arrhenius plot to capture the defect activation energy. The student will compile their results from the program and present them to the RF measurements group and at the MSU undergraduate research conference.

Scientific goals:   

• Characterize trapping effects in various GaN HEMTs and create Arrhenius plots to determine the salient trap activation energies.
• Study the effects of traps on GaN HEMT performance including DCIV and pulsed IV performance.

Student learning goals:

• Basic understanding of GaN HEMTs and their operation.
• Characterization techniques for measuring traps including DCT measurements.
• Basic understanding of traps and their impact on GaN HEMTs.
• Arrhenius plot analyses to determine trap activation energies.