The Impact of Low Temperature Materials on the Breakdown and Noise Properties of GaAs and InP Based Hemt's and FET's
Abstract
The breakdown voltage in GaAs field effect transistors (FET) has been the fundamental limitation of power performance in these devices. Previous studies have identified the high electric field at the drain edge of the gate metal as the cause of breakdown. At the start of this project, we successfully demonstrated that a low-temperature-grown GaAs (LTG-GaAs) surface 'insulator' dramatically improved the breakdown voltage in a GaAs MISFET. Subsequent device studies have concentrated on the use of LTG-GaAs as a surface passivation layer in GaAs MESFETs due to the potential shortcomings of a MESFET in its rf performance. Despite the early success, very little was known about the relevant electrical properties of LTG-GaAs. To better understand why LTG-GaAs works, what are its device limitations, and how device performance can be further improved, an extensive study of the material properties of LTG-GaAs has been carried out in parallel with device fabrication and testing. In this report, the results from our investigations will be split into two sections. The first section will discuss issues related to the fundamental understanding of LTG-GaAs, the second with device results using LTG-GaAs surface layers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 30, 1994
- Accession Number
- ADA285176
Entities
People
- Umesh Mishra
Organizations
- University of California, Santa Barbara