Low Resistivity n‐type GaN Ohmic Contacts on GaN Substrates
(2024) In Physica Status Solidi. A: Applications and Materials Science- Abstract
- In this study, a report is prepared on significantly low specific contact resistivity of alloyed and non-alloyed ohmic contacts fabricated on an as-grown n+-GaN layer and measured with the transfer length method. A low ρc = 8 × 10−8 Ω cm2 is extracted for the alloyed Ti/Al/Ni/Au, and ρc = 4 × 10−7 Ω cm2 for the unannealed Ti/Pd/Au. To achieve these, a highly doped n+-GaN layer with ND = 1.5 × 1019 cm−3 is used. The results are derived from a study of three different metal contact stacks, namely Ti/Al/Ni/Au (20 nm/300 nm/20 nm/400 nm), Ti/Pd/Au (2 nm/5 nm/200 nm), and Mo/Au (30 nm/200 nm). The Ti/Al/Ni/Au metal contact is studied in both annealed and non-annealed conditions, whereas for the Ti/Pd/Au and Mo/Au ohmic contacts, a study is... (More)
- In this study, a report is prepared on significantly low specific contact resistivity of alloyed and non-alloyed ohmic contacts fabricated on an as-grown n+-GaN layer and measured with the transfer length method. A low ρc = 8 × 10−8 Ω cm2 is extracted for the alloyed Ti/Al/Ni/Au, and ρc = 4 × 10−7 Ω cm2 for the unannealed Ti/Pd/Au. To achieve these, a highly doped n+-GaN layer with ND = 1.5 × 1019 cm−3 is used. The results are derived from a study of three different metal contact stacks, namely Ti/Al/Ni/Au (20 nm/300 nm/20 nm/400 nm), Ti/Pd/Au (2 nm/5 nm/200 nm), and Mo/Au (30 nm/200 nm). The Ti/Al/Ni/Au metal contact is studied in both annealed and non-annealed conditions, whereas for the Ti/Pd/Au and Mo/Au ohmic contacts, a study is conducted without annealing. Their performance and thermal stability are evaluated with a four-probe TLM, with temperatures ranging from 25 to 150 °C. Finally, a theoretical model based on thermionic emission theory is employed to gain a deeper understanding of the physical mechanisms governing the behavior of the ohmic contacts. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/c227b1c8-3931-4086-bda8-4b48c2e7bd6b
- author
- Logotheti, Adamantia
LU
; Garigapati, Navya Sri LU ; So, Byeongchan LU
; Colvin, Jovana LU ; Darakchieva, Vanya LU and Lind, Erik LU
- organization
- publishing date
- 2024-11-19
- type
- Contribution to journal
- publication status
- epub
- subject
- keywords
- gallium nitride (GaN), contact resistivity, alloyed and non-alloyed
- in
- Physica Status Solidi. A: Applications and Materials Science
- pages
- 6 pages
- publisher
- Wiley-VCH Verlag
- external identifiers
-
- scopus:85209774948
- ISSN
- 1862-6300
- DOI
- 10.1002/pssa.202400692
- language
- English
- LU publication?
- yes
- id
- c227b1c8-3931-4086-bda8-4b48c2e7bd6b
- date added to LUP
- 2024-11-27 16:53:17
- date last changed
- 2025-05-29 18:51:12
@article{c227b1c8-3931-4086-bda8-4b48c2e7bd6b, abstract = {{In this study, a report is prepared on significantly low specific contact resistivity of alloyed and non-alloyed ohmic contacts fabricated on an as-grown n+-GaN layer and measured with the transfer length method. A low ρc = 8 × 10−8 Ω cm2 is extracted for the alloyed Ti/Al/Ni/Au, and ρc = 4 × 10−7 Ω cm2 for the unannealed Ti/Pd/Au. To achieve these, a highly doped n+-GaN layer with ND = 1.5 × 1019 cm−3 is used. The results are derived from a study of three different metal contact stacks, namely Ti/Al/Ni/Au (20 nm/300 nm/20 nm/400 nm), Ti/Pd/Au (2 nm/5 nm/200 nm), and Mo/Au (30 nm/200 nm). The Ti/Al/Ni/Au metal contact is studied in both annealed and non-annealed conditions, whereas for the Ti/Pd/Au and Mo/Au ohmic contacts, a study is conducted without annealing. Their performance and thermal stability are evaluated with a four-probe TLM, with temperatures ranging from 25 to 150 °C. Finally, a theoretical model based on thermionic emission theory is employed to gain a deeper understanding of the physical mechanisms governing the behavior of the ohmic contacts.}}, author = {{Logotheti, Adamantia and Garigapati, Navya Sri and So, Byeongchan and Colvin, Jovana and Darakchieva, Vanya and Lind, Erik}}, issn = {{1862-6300}}, keywords = {{gallium nitride (GaN); contact resistivity; alloyed and non-alloyed}}, language = {{eng}}, month = {{11}}, publisher = {{Wiley-VCH Verlag}}, series = {{Physica Status Solidi. A: Applications and Materials Science}}, title = {{Low Resistivity n‐type GaN Ohmic Contacts on GaN Substrates}}, url = {{http://dx.doi.org/10.1002/pssa.202400692}}, doi = {{10.1002/pssa.202400692}}, year = {{2024}}, }