Abstract
We report on the electrical and microstructural analysis on Si/Ti/Al/Cu Ohmic contact for AlGaN/GaN high-electron-mobility transistors grown on Si (111) substrate. With optimized Si and Ti thickness in Si/Ti/Al/Cu Ohmic metallization, a minimum Ohmic contact resistance of 0.44 Ω mm and specific contact resistance of 3 × 10- 6 -cm2 with smooth surface morphology were achieved. Significant change in electrical performance and morphology showed high dependence of Ti and Si thickness on the multilayer metal scheme. Importantly, refractory behavior was shown in low annealing temperature, though uniform and continuous TiSix with low work function was formed on AlGaN. However, Ohmic behavior was shown in high annealing temperature, because thin AIN surrounding TiN promotes further N vacancies in GaN than the conventional Ti/Al-based Ohmic contact does. An outer Cu layer has low resistivity and the interfacial Si layer forms TiSix, which works as only a barrier to prevent Cu in-diffusion, not to transport current. As a result, we revealed that Ohmic contact mechanism in Si/Ti/Al/Cu is governed mainly by field emission near the Fermi level or themionic-field emission. Microstructural study on metal/semiconductor interface region was conducted by using transmission electron microscopy (TEM).
| Original language | English |
|---|---|
| Pages (from-to) | 60-63 |
| Number of pages | 4 |
| Journal | Microelectronic Engineering |
| Volume | 151 |
| DOIs | |
| Publication status | Published - 2016 Feb 5 |
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All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Surfaces, Coatings and Films
- Electrical and Electronic Engineering
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Interfacial AlN formation of Si/Ti/Al/Cu Ohmic contact for AlGaN/GaN high-electron-mobility transistors. / Yoon, Seonno; Bang, Jangwon; Lee, Hi Deok; Oh, Jungwoo.
In: Microelectronic Engineering, Vol. 151, 05.02.2016, p. 60-63.Research output: Contribution to journal › Article
TY - JOUR
T1 - Interfacial AlN formation of Si/Ti/Al/Cu Ohmic contact for AlGaN/GaN high-electron-mobility transistors
AU - Yoon, Seonno
AU - Bang, Jangwon
AU - Lee, Hi Deok
AU - Oh, Jungwoo
PY - 2016/2/5
Y1 - 2016/2/5
N2 - We report on the electrical and microstructural analysis on Si/Ti/Al/Cu Ohmic contact for AlGaN/GaN high-electron-mobility transistors grown on Si (111) substrate. With optimized Si and Ti thickness in Si/Ti/Al/Cu Ohmic metallization, a minimum Ohmic contact resistance of 0.44 Ω mm and specific contact resistance of 3 × 10- 6 -cm2 with smooth surface morphology were achieved. Significant change in electrical performance and morphology showed high dependence of Ti and Si thickness on the multilayer metal scheme. Importantly, refractory behavior was shown in low annealing temperature, though uniform and continuous TiSix with low work function was formed on AlGaN. However, Ohmic behavior was shown in high annealing temperature, because thin AIN surrounding TiN promotes further N vacancies in GaN than the conventional Ti/Al-based Ohmic contact does. An outer Cu layer has low resistivity and the interfacial Si layer forms TiSix, which works as only a barrier to prevent Cu in-diffusion, not to transport current. As a result, we revealed that Ohmic contact mechanism in Si/Ti/Al/Cu is governed mainly by field emission near the Fermi level or themionic-field emission. Microstructural study on metal/semiconductor interface region was conducted by using transmission electron microscopy (TEM).
AB - We report on the electrical and microstructural analysis on Si/Ti/Al/Cu Ohmic contact for AlGaN/GaN high-electron-mobility transistors grown on Si (111) substrate. With optimized Si and Ti thickness in Si/Ti/Al/Cu Ohmic metallization, a minimum Ohmic contact resistance of 0.44 Ω mm and specific contact resistance of 3 × 10- 6 -cm2 with smooth surface morphology were achieved. Significant change in electrical performance and morphology showed high dependence of Ti and Si thickness on the multilayer metal scheme. Importantly, refractory behavior was shown in low annealing temperature, though uniform and continuous TiSix with low work function was formed on AlGaN. However, Ohmic behavior was shown in high annealing temperature, because thin AIN surrounding TiN promotes further N vacancies in GaN than the conventional Ti/Al-based Ohmic contact does. An outer Cu layer has low resistivity and the interfacial Si layer forms TiSix, which works as only a barrier to prevent Cu in-diffusion, not to transport current. As a result, we revealed that Ohmic contact mechanism in Si/Ti/Al/Cu is governed mainly by field emission near the Fermi level or themionic-field emission. Microstructural study on metal/semiconductor interface region was conducted by using transmission electron microscopy (TEM).
UR - http://www.scopus.com/inward/record.url?scp=84951000536&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84951000536&partnerID=8YFLogxK
U2 - 10.1016/j.mee.2015.12.005
DO - 10.1016/j.mee.2015.12.005
M3 - Article
AN - SCOPUS:84951000536
VL - 151
SP - 60
EP - 63
JO - Microelectronic Engineering
JF - Microelectronic Engineering
SN - 0167-9317
ER -