Reduction of contact resistance between Ni-InGaAs and n-InGaAs by Ge2Sb2Te5 interlayer

A method using a Ge2Sb2Te5 (GST) interlayer is proposed for reducing the specific contact resistivity (rho(c)) between a self-aligned Ni-InGaAs alloy and the n-In0.53Ga0.47As substrate. Compared with a control sample, a substantially lower rho(c) was obtained by applying the GST interlayer, followed by the in situ deposition of a Ni/TiN layer. rho(c) was reduced by more than 2 orders of magnitude, from 3.1 x 10(-5) to 1.01 x 10(-7) Omega-cm(2), with the GST interlayer. The reduction in the contact resistance was due to the suppression of oxidation in the Ni-InGaAs alloy and at the interface between the Ni-InGaAs and n-InGaAs. (c) 2017 The Japan Society of Applied Physics