Electrical and Structural Properties of W-Capped Er Ohmic Contact to n-Type in0.53Ga0.47As Channel

Tuesday, 7 October 2014
Expo Center, 1st Floor, Center and Right Foyers (Moon Palace Resort)
C. H. Leem, M. S. Kang, Y. J. Lee, Y. R. Lim, K. H. Shim, and C. J. Choi (Chonbuk National University)
We have investigated electrical and microstructural properties of W-capped Er Ohmic contact to n-type In0.53Ga0.47As channel using (I-V) current-voltage characteristics, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The interfacial reaction between Er and In0.53Ga0.47As driven by rapid thermal annealing (RTA) process led to the formation of Er-InGaAs alloy. The increase in the RTA temperature resulted in the degradation of surface and interface morphologies of Er-InGaAs alloy film, which could be associated with the reduction of its surface energy combined with intense interfacial reaction between Er and In0.53Ga0.47As. The specific contact resistivity of Er-InGaAs alloy film extracted using four-point (Kelvin) probe technique was investigated as a function of RTA temperature. The specific contact resistivity was found to vary with the variation in RTA temperature. Such a dependency of specific contact resistivity on RTA temperature could be attributed to the phase evolution surface/interface morphologies of Er-InGaAs alloy film. A minimum specific contact resistivity of ~ 10-6 Ωcm2 was achieved after RTA process at 400 °C.