Abstract
A Ti(12 nm)/W(20 nm)/Au(50 nm) metallization scheme has been investigated for obtaining thermally stable low-resistance ohmic contacts to n-type GaN (4.0×1018 cm-3). It is shown that the current-voltage (I-V) characteristics of the samples are abnormally dependent on the annealing temperature. For example, the samples that were annealed at temperatures below 750 °C for 1 min in a N2 ambient show rectifying behavior. However, annealing the samples at temperatures in excess of 850 °C results in linear I-V characteristics. The contact produces a specific contact resistance as low as 8.4×10-6 Ω∈cm2 when annealed at 900 °C. It is further shown that the contacts are fairly thermally stable even after annealing at 900 °C; annealing the samples at 900 °C for 30 min causes insignificant degradation of the electrical and structural properties. Based on glancing angle X-ray diffraction and Auger electron microscopy results, the abnormal temperature dependence of the ohmic behavior is described and discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 561-564 |
| Number of pages | 4 |
| Journal | Applied Physics A: Materials Science and Processing |
| Volume | 81 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2005 Aug 1 |
| Externally published | Yes |
Fingerprint
ASJC Scopus subject areas
- Materials Science(all)
- Physics and Astronomy (miscellaneous)
Cite this
Formation of thermally stable low-resistance Ti/W/Au ohmic contacts on n-type GaN. / Reddy, V. R.; Kim, S. H.; Seong, Tae Yeon.
In: Applied Physics A: Materials Science and Processing, Vol. 81, No. 3, 01.08.2005, p. 561-564.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Formation of thermally stable low-resistance Ti/W/Au ohmic contacts on n-type GaN
AU - Reddy, V. R.
AU - Kim, S. H.
AU - Seong, Tae Yeon
PY - 2005/8/1
Y1 - 2005/8/1
N2 - A Ti(12 nm)/W(20 nm)/Au(50 nm) metallization scheme has been investigated for obtaining thermally stable low-resistance ohmic contacts to n-type GaN (4.0×1018 cm-3). It is shown that the current-voltage (I-V) characteristics of the samples are abnormally dependent on the annealing temperature. For example, the samples that were annealed at temperatures below 750 °C for 1 min in a N2 ambient show rectifying behavior. However, annealing the samples at temperatures in excess of 850 °C results in linear I-V characteristics. The contact produces a specific contact resistance as low as 8.4×10-6 Ω∈cm2 when annealed at 900 °C. It is further shown that the contacts are fairly thermally stable even after annealing at 900 °C; annealing the samples at 900 °C for 30 min causes insignificant degradation of the electrical and structural properties. Based on glancing angle X-ray diffraction and Auger electron microscopy results, the abnormal temperature dependence of the ohmic behavior is described and discussed.
AB - A Ti(12 nm)/W(20 nm)/Au(50 nm) metallization scheme has been investigated for obtaining thermally stable low-resistance ohmic contacts to n-type GaN (4.0×1018 cm-3). It is shown that the current-voltage (I-V) characteristics of the samples are abnormally dependent on the annealing temperature. For example, the samples that were annealed at temperatures below 750 °C for 1 min in a N2 ambient show rectifying behavior. However, annealing the samples at temperatures in excess of 850 °C results in linear I-V characteristics. The contact produces a specific contact resistance as low as 8.4×10-6 Ω∈cm2 when annealed at 900 °C. It is further shown that the contacts are fairly thermally stable even after annealing at 900 °C; annealing the samples at 900 °C for 30 min causes insignificant degradation of the electrical and structural properties. Based on glancing angle X-ray diffraction and Auger electron microscopy results, the abnormal temperature dependence of the ohmic behavior is described and discussed.
UR - http://www.scopus.com/inward/record.url?scp=21644482411&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=21644482411&partnerID=8YFLogxK
U2 - 10.1007/s00339-004-2673-3
DO - 10.1007/s00339-004-2673-3
M3 - Article
AN - SCOPUS:21644482411
VL - 81
SP - 561
EP - 564
JO - Applied Physics
JF - Applied Physics
SN - 0340-3793
IS - 3
ER -