Title :
Low-resistance Ohmic contacts to digital alloys of n-AlGaN/AlN
Author :
Yun, J. ; Choi, K. ; Mathur, K. ; Kuryatkov, V. ; Borisov, B. ; Kipshidze, G. ; Nikishin, S. ; Temkin, H.
Author_Institution :
Dept. of Electr. Eng., Texas Tech Univ., Lubbock, TX, USA
Abstract :
Low contact resistance to digital alloys of n-type AlGaN/AlN with high average Al concentration is described. Low-energy electron diffraction was used to evaluate surface precleaning with HCl and buffered HF. The contact metallization consisting of a stack of Ti/Al/Ti/Au, 20/100/45/60 nm in thickness, was e-beam deposited and etch-patterned. The lowest specific contact resistance of 5.6×10-5 Ω·cm2 was obtained after annealing in N2 ambient at 700°C.
Keywords :
III-V semiconductors; aluminium; aluminium compounds; annealing; contact resistance; electron beam deposition; gallium compounds; gold; low energy electron diffraction; metallisation; ohmic contacts; semiconductor superlattices; surface cleaning; wide band gap semiconductors; 100 nm; 20 nm; 45 nm; 60 nm; 700 C; AlGaN-AlN; Ti-Al-Ti-Au; annealing process; contact metallization; digital alloys; electron-beam deposition; light-emitting diodes; low contact resistance; low-energy electron diffraction; ohmic contacts; superlattice structure; surface precleaning; Aluminum gallium nitride; Contact resistance; Diffraction; Digital alloys; Electrons; Gold; Hafnium; Metallization; Ohmic contacts; Surface resistance; AlGaN; GaN; light-emitting diode; ohmic contact; superlattices;
Journal_Title :
Electron Device Letters, IEEE
DOI :
10.1109/LED.2005.861255
