Physics of On-State Breakdown in InAIAs/InGaAs High Electron Mobility Transistors

Franklin W. Olin College Of Engineering, Needham MA

Investigators

Abstract

9906552 Somerville The goal of this proposal is to illuminate experimentally the physics of burnout and on-state breakdown in InAlAs/InGaAs high electron mobility transistors (HEMTs). These devices are extremely attractive for a growing number of high frequency applications, including collision avoidance radar systems, wireless LANS, and ultra high speed switching networks. Many of the applications require high breakdown voltage; as a result, great effort has been devoted to understanding and improving off-state breakdown in InAlAs/InGaAs HEMTs. However, as off-state breakdown has improved, it has become clear that the bottleneck is the problem of on-state breakdown and associated burnout. Relatively little work has been done in this area. It is thought that impact ionization is involved, but the details of the mechanism are unknown, as are the impact of various device design parameters. By investigating the physics of on-state breakdown and burnout, the proposed research program will identify promising design directions for InAlAs/InGaAs HEMTs to help alleviate the problem. The research program involves development of a customized measurement system to allow visible and NIR spectroscopy of on-state breakdown in InAlAs/InGaAs HEMTs under a variety of thermal and bias conditions; the use of the system for extensive measurements on a large sample set of state-of-the-art devices; and extensive data reduction and model development. The project is designed with student participation in mind; much of the work will be done by undergraduate researchers under the supervision of the PI. Thus, in addition to enhancing understanding of the problem of on-state breakdown, the proposed research program will introduce undergraduate students to modern research techniques and instrumentation in the area of device physics, and will afford these students the opportunity to do real research on a critical technology. ***