Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts
Abstract Epitaxial regrowth processes are presented for achieving Al‐rich aluminum gallium nitride (AlGaN) high electron mobility transistor (HEMTs) with p‐type gates with large, positive threshold voltage for enhancement mode operation and low resistance Ohmic contacts. Utilizing a deep gate recess...
Saved in:
| Main Authors: | , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley-VCH
2025-01-01
|
| Series: | Advanced Materials Interfaces |
| Subjects: | |
| Online Access: | https://doi.org/10.1002/admi.202301080 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832593513733160960 |
|---|---|
| author | Brianna Klein Andrew Allerman Andrew Armstrong Mary Rosprim Colin Tyznik Yinxuan Zhu Chandan Joishi Chris Chae Siddharth Rajan |
| author_facet | Brianna Klein Andrew Allerman Andrew Armstrong Mary Rosprim Colin Tyznik Yinxuan Zhu Chandan Joishi Chris Chae Siddharth Rajan |
| author_sort | Brianna Klein |
| collection | DOAJ |
| description | Abstract Epitaxial regrowth processes are presented for achieving Al‐rich aluminum gallium nitride (AlGaN) high electron mobility transistor (HEMTs) with p‐type gates with large, positive threshold voltage for enhancement mode operation and low resistance Ohmic contacts. Utilizing a deep gate recess etch into the channel and an epitaxial regrown p‐AlGaN gate structure, an Al0.85Ga0.15N barrier/Al0.50Ga0.50N channel HEMT with a large positive threshold voltage (VTH = +3.5 V) and negligible gate leakage is demonstrated. Epitaxial regrowth of AlGaN avoids the use of gate insulators which can suffer from charge trapping effects observed in typical dielectric layers deposited on AlGaN. Low resistance Ohmic contacts (minimum specific contact resistance = 4 × 10−6 Ω cm2, average = 1.8 × 10−4 Ω cm2) are demonstrated in an Al0.85Ga0.15N barrier/Al0.68Ga0.32N channel HEMT by employing epitaxial regrowth of a heavily doped, n‐type, reverse compositionally graded epitaxial structure. The combination of low‐leakage, large positive threshold p‐gates and low resistance Ohmic contacts by the described regrowth processes provide a pathway to realizing high‐current, enhancement‐mode, Al‐rich AlGaN‐based ultra‐wide bandgap transistors. |
| format | Article |
| id | doaj-art-fa9e7d2d7dae430ba486b150f88fd25a |
| institution | Kabale University |
| issn | 2196-7350 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | Wiley-VCH |
| record_format | Article |
| series | Advanced Materials Interfaces |
| spelling | doaj-art-fa9e7d2d7dae430ba486b150f88fd25a2025-01-20T13:56:18ZengWiley-VCHAdvanced Materials Interfaces2196-73502025-01-01122n/an/a10.1002/admi.202301080Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic ContactsBrianna Klein0Andrew Allerman1Andrew Armstrong2Mary Rosprim3Colin Tyznik4Yinxuan Zhu5Chandan Joishi6Chris Chae7Siddharth Rajan8Sandia National Laboratories PO Box 5800 Albuquerque NM 87185‐1085 USASandia National Laboratories PO Box 5800 Albuquerque NM 87185‐1085 USASandia National Laboratories PO Box 5800 Albuquerque NM 87185‐1085 USASandia National Laboratories PO Box 5800 Albuquerque NM 87185‐1085 USASandia National Laboratories PO Box 5800 Albuquerque NM 87185‐1085 USA205 Dreese Laboratory 2015 Neil Avenue Columbus OH 43210 USA205 Dreese Laboratory 2015 Neil Avenue Columbus OH 43210 USA205 Dreese Laboratory 2015 Neil Avenue Columbus OH 43210 USA205 Dreese Laboratory 2015 Neil Avenue Columbus OH 43210 USAAbstract Epitaxial regrowth processes are presented for achieving Al‐rich aluminum gallium nitride (AlGaN) high electron mobility transistor (HEMTs) with p‐type gates with large, positive threshold voltage for enhancement mode operation and low resistance Ohmic contacts. Utilizing a deep gate recess etch into the channel and an epitaxial regrown p‐AlGaN gate structure, an Al0.85Ga0.15N barrier/Al0.50Ga0.50N channel HEMT with a large positive threshold voltage (VTH = +3.5 V) and negligible gate leakage is demonstrated. Epitaxial regrowth of AlGaN avoids the use of gate insulators which can suffer from charge trapping effects observed in typical dielectric layers deposited on AlGaN. Low resistance Ohmic contacts (minimum specific contact resistance = 4 × 10−6 Ω cm2, average = 1.8 × 10−4 Ω cm2) are demonstrated in an Al0.85Ga0.15N barrier/Al0.68Ga0.32N channel HEMT by employing epitaxial regrowth of a heavily doped, n‐type, reverse compositionally graded epitaxial structure. The combination of low‐leakage, large positive threshold p‐gates and low resistance Ohmic contacts by the described regrowth processes provide a pathway to realizing high‐current, enhancement‐mode, Al‐rich AlGaN‐based ultra‐wide bandgap transistors.https://doi.org/10.1002/admi.202301080semiconductorstransistorsultra‐wide bandgaps |
| spellingShingle | Brianna Klein Andrew Allerman Andrew Armstrong Mary Rosprim Colin Tyznik Yinxuan Zhu Chandan Joishi Chris Chae Siddharth Rajan Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts Advanced Materials Interfaces semiconductors transistors ultra‐wide bandgaps |
| title | Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts |
| title_full | Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts |
| title_fullStr | Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts |
| title_full_unstemmed | Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts |
| title_short | Al‐Rich AlGaN Transistors with Regrown p‐AlGaN Gate Layers and Ohmic Contacts |
| title_sort | al rich algan transistors with regrown p algan gate layers and ohmic contacts |
| topic | semiconductors transistors ultra‐wide bandgaps |
| url | https://doi.org/10.1002/admi.202301080 |
| work_keys_str_mv | AT briannaklein alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT andrewallerman alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT andrewarmstrong alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT maryrosprim alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT colintyznik alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT yinxuanzhu alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT chandanjoishi alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT chrischae alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts AT siddharthrajan alrichalgantransistorswithregrownpalgangatelayersandohmiccontacts |