Browsing by Author "Yeh, MH"

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Low resistance Ohmic contacts to n-GaN by Ar plasma and forming gas ambient treatments
(2003-07-01)
Lee, CC
;
Lee, CP
;
Yeh, MH
;
Lee, WI
;
Kuo, CT
In this article, a scheme for fabricating low resistance Ohmic contacts to n-GaN was developed. This approach takes advantage of Ar plasma treatment and thermal annealing in forming gas ambient. As a result, the adjustment of Ar flow rate was very effective in improving the contact resistance. After proper Ar plasma treatment, the contact resistance and specific contact resistance of as-deposited Ohmic contacts were reduced to 0.362 Omega mm and 3.9 x 10(-5) Omega cm(2), respectively. Low contact resistance (0.103 Omega mm) and specific contact resistance (3.2 x 10(-6) Omega cm(2)) were obtained after annealing in N-2 gas ambient. By performing thermal annealing in forming gas ambient, even lower contact resistance (0.093 Omega mm) and specific contact resistance (2.6 x 10(-6) Omega cm(2)) were successfully achieved, indicating that the electrical characteristics of Ohmic contacts would not be affected by the effect of hydrogen passivation of dopants in n-GaN. (C) 2003 American Vacuum Society.
Thermal stability of plasma-treated ohmic contacts to n-GaN
(2003-04-01)
Lee, CC
;
Lin, SD
;
Lee, CP
;
Yeh, MH
;
Lee, WI
In this study, the thermal stability of plasma-treated ohmic contacts by either Cl-2/Ar or Ar plasma to n-GaN was investigated by high-temperature aging tests. With proper plasma treatment, ohmic contacts to n-GaN have a lower contact resistance than those without plasma treatment. High-temperature aging tests were performed at temperatures ranging from 400 to 600degreesC for 2h in N-2 or air ambient. No apparent electrical degradation in contact resistance was observed after aging, showing the thermal stability of plasma-treated ohmic contacts is not affected by the recovery of plasma-induced damages on the wafer surface.