© The Institution of Engineering and Technology
An effective surface treatment method has been developed to realise low resistance ohmic contacts on the lapped backsides of m-plane n-GaN substrates with a moderate doping level of 5.5×1017 cm−3. Ti/Al/Au contacts with fine polishing and an ICP treatment followed by annealing at 700°C for 5 min yielded a specific contact resistance as low as 3.9×10−5 Ωcm2. The same low specific contact resistance was also achieved by annealing at 500°C for 5 min on a relatively rough surface. The effective removal of the lapping damage by ICP treatment and the creation of nitrogen vacancies during annealing are believed to improve the contacts.
References
-
-
1)
-
L.L. Smith ,
R.F. Davis ,
R.-J. Liu ,
M.J. Kim ,
R.W. Carpenter
.
Microstructure, electrical properties, and thermal stability of Ti-based ohmic contacts to n-GaN.
J. Mater. Res.
,
1032 -
1038
-
2)
-
D.K. Schroder
.
(2005)
Semiconductor material and device characterization.
-
3)
-
Y.-D. Lin ,
A. Chakraborty ,
S. Brinkley ,
H.C. Kuo ,
T. Melo ,
K. Fujito ,
J.S. Speck ,
S.P. DenBaars ,
S. Nakamura
.
Characterization of blue-green m-plane InGaN light emitting diodes.
Appl. Phys. Lett.
-
4)
-
R.H. Cox ,
H. Strack
.
Ohmic contacts for GaAs devices.
Solid-State Electron.
,
1213 -
1218
-
5)
-
L. Wang ,
F.M. Mohammed ,
I. Adesida
.
Characterization of Au and Al segregation layer in post-annealed thin Ti/Al/Mo/Au ohmic contacts to n-GaN.
J. Appl. Phys.
-
6)
-
K. Okamoto ,
J. Kashiwagi ,
T. Tanaka ,
M. Kubota
.
Nonpolar m-plane InGaN multiple quantum well laser diodes with a lasing wavelength of 499.8 nm.
Appl. Phys. Lett.
-
7)
-
S.N. Mohammad
.
Contact mechanisms and design principles for nonalloyed ohmic contacts to n-GaN.
J. Appl. Phys.
,
4856 -
4865
http://iet.metastore.ingenta.com/content/journals/10.1049/el.2010.2976
Related content
content/journals/10.1049/el.2010.2976
pub_keyword,iet_inspecKeyword,pub_concept
6
6