Detailed investigations of trap-induced degradation mechanisms in GaN HEMTs
Abstract
Detailed investigations of trap-induced degradation mechanisms in GaN HEMTsShort SOW:Funds are provided to investigate defects in GaN HEMTs for RF applicationsThe PI is Prof. Aaron Arehart at the Ohio State University.This is a 36-month grantThis grant will continue the investigation of the source, impact, and dependence on stressing of deep levels in GaN HEMTs and MMICs, identify how formation or activation of deep levels are accelerated by temperature and electric field, and use newly developed nm-scale defect characterization techniques with conventional chemical and physical characterization techniques to quickly and directly identify the location and physical sources of the detrimental defects in GaN devices to advance future device designs and technologies. Specifically this program, will quantify the defects responsible for degradation and non-ideal behavior in GaN HEMTs, identify the source and location of these defects, understand how electric fields and temperature cause trap formation, activation, or dehydrogenation of these defects, and understand how these defects or new defects will impact next generation devices (e.g. N-polar HEMTs).Objective:Identify and quantify trap related degradation processes and stressors in GaN HEMTs and MMIC sApproach:The research effort is organized into six inter-related, thrusts.DC vs RF stressing of HEMTsWe propose a systematic study to investigate the specific traps formed/activated under different DC life testing conditions with RF life tested MMICs to determine the traps formed at the various conditions, determine which traps are responsible for degradation of each HEMT terminal characteristic, and then the conditions that most match the RF life testing results on the same family of Triquint HEMTs.GaN HEMT buffer designsTwo known buffer designs from AFRL will be investigated before and after RF accelerated life testing. The wafers are grown by commercial vendors and processed at AFRL where they have demonstrated high yield, high uniformity GaN HEMTs. This is a unique opportunity to have access to all the details of the devices and growths unlike commercial devices and AFRL~s processing capabilities will ensure the results are not due to the variability of processing or growth.Degradation in HEMTs with and without field platesTHe push to mm-wave devices has lead to the requirement to characterize non field plate device reliability. Devices will be characterized using CID-DLTS and CID-DLOS in both gate and drain control to study defects under the gate and in the access regions along with pulsed and DC I-V to relate the defects to the changes in the terminal characteristics. This will be compared to RF life testing of these samples in order to understand the defects causing degradation in these HEMTs.Investigation of different class operating points during stressingThe deep levels in GaN HEMTs subjected to RF life testing at different amplifier class operating points such as A/B, and class E will be compared.Scanning-DLTS and scanning-DLOSThis is a new DURIP-funded instrument that will greatly expand the capability and the accessible trap energies spectrum that can be investigated in GaN.Characterization of N-face HEMTSThis effort will begin the first characterization of defects in nitrogen-polar GaN HEMT devices in collaboration with UCSB.Merit and RelevanceThis effort builds on prior D&I projects, nitrogen-polar W-band devices and t and the DRIFT MURI. Advancing GaN HEMTs technology for high-reliability applications through the identification of specific limiting traps will substantially advance a variety of DoD electronic systems.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Sep 30, 2016
- Source ID
- N000141612932
Entities
People
- Aaron R. Arehart
Organizations
- Office of Naval Research
- Ohio State University
- United States Navy