Thermal stability of Pd/Zn and Pt based contacts to p- In0.53Ga0.47AsInP with various barrier layers
P.W. Leecha, G.K. Reevesb, W. Zhoub, P. Resselc
Published in:
J. Vac. Sci. Technol. B, vol. 16, no. 1, pp. 227–231 (1998).
Abstract:
Pd/Zn/Au contacts to p- In0.53Ga0.47AsInP with various types of barrier layers to the indiffusion of Au have been examined by Rutherford backscattering spectrometry (RBS). For the metallizations with a barrier layer of Pd, the aging of the contacts at 400°C for 20 h produced a widespread indiffusion of Au for all thicknesses of the Pd. In comparison, the incorporation of a layer of Pt or amorphous LaB6 in the contacts prevented an indiffusion of Au and significantly reduced any outdiffusion of the semiconductor elements. The presence of the barrier layer of Pt or LaB6 produced little or no detrimental increase in ρc for this contact system. In the as-deposited Pd-based contacts, a layer of Zn in the structure was necessary in order to produce a minimum value of ρc. After annealing at 500°C, a specific contact resistance in the range 8-10×10-6 Ω cm2 was obtained for all of the contacts based on Pd/Zn/Au. A comparison has been made with the characteristics of Pt/Ti/Pt/Au contacts to p- In0.53Ga0.47AsInP which were shown as stable against the indiffusion of Au.
a CSIRO Division of Manufacturing Science and Technology, Clayton, 3168, Victoria, Australia
b Department of Communication and Electronic Engineering, R.M.I.T., Melbourne, Victoria, Australia
c Ferdinand-Braun-Institut für Höchstfrequenztechnik, Rudower Chaussee 5, D-12489 Berlin, Germany
Topics:
Metallization process, Contact impedance, Materials properties
© 1998 American Vacuum Society.
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