Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing
The reliability of GaN-based devices operating under high temperatures is crucial for their application in extreme environments. To identify the fundamental mechanisms behind high-temperature degradation, we investigated GaN-on-sapphire Schottky barrier diodes (SBDs) under simultaneous heating and e...
Saved in:
| Main Authors: | , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-02-01
|
| Series: | Micromachines |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2072-666X/16/3/242 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850279863971217408 |
|---|---|
| author | Nahid Sultan Al-Mamun Yuxin Du Jianan Song Rongming Chu Aman Haque |
| author_facet | Nahid Sultan Al-Mamun Yuxin Du Jianan Song Rongming Chu Aman Haque |
| author_sort | Nahid Sultan Al-Mamun |
| collection | DOAJ |
| description | The reliability of GaN-based devices operating under high temperatures is crucial for their application in extreme environments. To identify the fundamental mechanisms behind high-temperature degradation, we investigated GaN-on-sapphire Schottky barrier diodes (SBDs) under simultaneous heating and electrical biasing. We observed the degradation mechanisms in situ inside a transmission electron microscope (TEM) using a custom-fabricated chip for simultaneous thermal and electrical control. The pristine device exhibited a high density of extended defects, primarily due to lattice mismatch and thermal expansion differences between the GaN and sapphire. TEM and STEM imaging, coupled with energy-dispersive X-ray spectroscopy (EDS), revealed the progressive degradation of the diode with increasing bias and temperature. At higher bias levels (4–5 V) and elevated temperatures (300–455 °C), the interdiffusion and alloying of the Au/Pd Schottky metal stack with GaN, along with defect generation near the interface, resulted in Schottky contact failure and catastrophic device degradation. A geometric phase analysis further identified strain localization and lattice distortions induced by thermal and electrical stresses, which facilitated diffusion pathways for rapid metal atom migration. These findings highlight that defect-mediated electrothermal degradation and interfacial chemical reactions are critical elements in the high-temperature failure physics of GaN Schottky diodes. |
| format | Article |
| id | doaj-art-2f973a8cedd24f3db99c1b241bc633e3 |
| institution | OA Journals |
| issn | 2072-666X |
| language | English |
| publishDate | 2025-02-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Micromachines |
| spelling | doaj-art-2f973a8cedd24f3db99c1b241bc633e32025-08-20T01:48:57ZengMDPI AGMicromachines2072-666X2025-02-0116324210.3390/mi16030242Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward BiasingNahid Sultan Al-Mamun0Yuxin Du1Jianan Song2Rongming Chu3Aman Haque4Department of Mechanical Engineering, Penn State University, University Park, PA 16802, USADepartment of Electrical Engineering, Penn State University, University Park, PA 16802, USADepartment of Electrical Engineering, Penn State University, University Park, PA 16802, USADepartment of Electrical Engineering, Penn State University, University Park, PA 16802, USADepartment of Mechanical Engineering, Penn State University, University Park, PA 16802, USAThe reliability of GaN-based devices operating under high temperatures is crucial for their application in extreme environments. To identify the fundamental mechanisms behind high-temperature degradation, we investigated GaN-on-sapphire Schottky barrier diodes (SBDs) under simultaneous heating and electrical biasing. We observed the degradation mechanisms in situ inside a transmission electron microscope (TEM) using a custom-fabricated chip for simultaneous thermal and electrical control. The pristine device exhibited a high density of extended defects, primarily due to lattice mismatch and thermal expansion differences between the GaN and sapphire. TEM and STEM imaging, coupled with energy-dispersive X-ray spectroscopy (EDS), revealed the progressive degradation of the diode with increasing bias and temperature. At higher bias levels (4–5 V) and elevated temperatures (300–455 °C), the interdiffusion and alloying of the Au/Pd Schottky metal stack with GaN, along with defect generation near the interface, resulted in Schottky contact failure and catastrophic device degradation. A geometric phase analysis further identified strain localization and lattice distortions induced by thermal and electrical stresses, which facilitated diffusion pathways for rapid metal atom migration. These findings highlight that defect-mediated electrothermal degradation and interfacial chemical reactions are critical elements in the high-temperature failure physics of GaN Schottky diodes.https://www.mdpi.com/2072-666X/16/3/242GaN Schottky diodein situ TEMhigh-temperature operation of GaNelectrothermal degradation of GaNreliability of GaN |
| spellingShingle | Nahid Sultan Al-Mamun Yuxin Du Jianan Song Rongming Chu Aman Haque Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing Micromachines GaN Schottky diode in situ TEM high-temperature operation of GaN electrothermal degradation of GaN reliability of GaN |
| title | Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing |
| title_full | Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing |
| title_fullStr | Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing |
| title_full_unstemmed | Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing |
| title_short | Electrothermal Failure Physics of GaN Schottky Diodes Under High-Temperature Forward Biasing |
| title_sort | electrothermal failure physics of gan schottky diodes under high temperature forward biasing |
| topic | GaN Schottky diode in situ TEM high-temperature operation of GaN electrothermal degradation of GaN reliability of GaN |
| url | https://www.mdpi.com/2072-666X/16/3/242 |
| work_keys_str_mv | AT nahidsultanalmamun electrothermalfailurephysicsofganschottkydiodesunderhightemperatureforwardbiasing AT yuxindu electrothermalfailurephysicsofganschottkydiodesunderhightemperatureforwardbiasing AT jianansong electrothermalfailurephysicsofganschottkydiodesunderhightemperatureforwardbiasing AT rongmingchu electrothermalfailurephysicsofganschottkydiodesunderhightemperatureforwardbiasing AT amanhaque electrothermalfailurephysicsofganschottkydiodesunderhightemperatureforwardbiasing |