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An innovative circuit for testing hot carrier and trap generation in GaN Devices

Moshe Azoulay, Gilad Orr, Gady Golan

TL;DR

GaN power transistors offer high performance but reliability under high voltage/current remains a concern. The authors develop a novel boost-converter-based stress test and apply it to EPC2038 GaN transistors to accelerate hot-carrier and trap generation. They observe RDS(on) increasing with time following a log-law under HV stress, supporting the EPC first-principles model and enabling accelerated life predictions. The work provides a practical reliability-testing framework for GaN devices and informs MTOL model development and device design for robust high-frequency, high-power applications.

Abstract

Microelectronic devices in modern systems are working continuously for prolonged periods of many years. Thus, there is a crucial need for reliability model that will enable us to predict precisely the life cycle of the device and point out on the governing failure mechanisms that are responsible for degradation and failure. This is even more important when high power and frequency devices, especially Normally Off Switch Power transistors are concerned, since the reliability research on those devices lay far behind that of low power digital devices. Our main goal in our lab is to investigate the failure mechanisms of GaN transistors, aimed at determining the reliability factors of the innovative MTOL model. The main goal is to understand the reason for the transformation of the failure mechanism. Employing the recorded data may enable us to predict the performance and life time of the device at different operation parameters such as current, voltage, frequency and temperatures. In this study we employ a new different use for the well-known boost convertor circuit, based on GaN Devices in order to stress the transistor to the maximum values of voltage and current which allows us to examine the reliability of the transistor and accelerating Hot Carrier And Trap Generation failures mechanisms. The acceleration of the failure mechanism should be done in a way that will not affect the electronic device detrimentally and on the other hand we would not need to wait a long time in order to observe the degradation. In this work we will present our new boost converter circuit based on high power GaN HEMT.

An innovative circuit for testing hot carrier and trap generation in GaN Devices

TL;DR

GaN power transistors offer high performance but reliability under high voltage/current remains a concern. The authors develop a novel boost-converter-based stress test and apply it to EPC2038 GaN transistors to accelerate hot-carrier and trap generation. They observe RDS(on) increasing with time following a log-law under HV stress, supporting the EPC first-principles model and enabling accelerated life predictions. The work provides a practical reliability-testing framework for GaN devices and informs MTOL model development and device design for robust high-frequency, high-power applications.

Abstract

Microelectronic devices in modern systems are working continuously for prolonged periods of many years. Thus, there is a crucial need for reliability model that will enable us to predict precisely the life cycle of the device and point out on the governing failure mechanisms that are responsible for degradation and failure. This is even more important when high power and frequency devices, especially Normally Off Switch Power transistors are concerned, since the reliability research on those devices lay far behind that of low power digital devices. Our main goal in our lab is to investigate the failure mechanisms of GaN transistors, aimed at determining the reliability factors of the innovative MTOL model. The main goal is to understand the reason for the transformation of the failure mechanism. Employing the recorded data may enable us to predict the performance and life time of the device at different operation parameters such as current, voltage, frequency and temperatures. In this study we employ a new different use for the well-known boost convertor circuit, based on GaN Devices in order to stress the transistor to the maximum values of voltage and current which allows us to examine the reliability of the transistor and accelerating Hot Carrier And Trap Generation failures mechanisms. The acceleration of the failure mechanism should be done in a way that will not affect the electronic device detrimentally and on the other hand we would not need to wait a long time in order to observe the degradation. In this work we will present our new boost converter circuit based on high power GaN HEMT.

Paper Structure

This paper contains 14 sections, 4 equations, 19 figures, 1 table.

Table of Contents

  1. Introduction
  2. TESTING METHOD & SETUP CONFIGURATIONS
  3. Boost Converter
  4. Boost Converter Operation
  5. Boost convertor based on the EPC 2038 GaN transistor
  6. $GaN$ DEGRADATION MECHANISMS
  7. Hot -Carriers and Trap Generation
  8. Contact Degradation
  9. RESULTS OF THE EXPERIMENTAL TESTS
  10. Boost converter HVRB continues test
  11. Test with 40V stress, 400mA
  12. Test with 70V stress, 400mA
  13. Test with 100V stress, 400mA
  14. DISCUSSION

Figures (19)

  • Figure 1: (top) simplified representation of a switching mode power converter (boost configuration); (bottom) simplified representation of the different operating regimes of the transistor in a boost converter.
  • Figure 2: Current Path with GaN Off
  • Figure 3: Boost Converter Operation at Switch On
  • Figure 4: Current Path with GaN Off
  • Figure 5: Current Path with GaN On
  • ...and 14 more figures