Tb/Ni/TiN Stack for Ultralow Contact Resistive Ni‐Tb‐InGaAs Alloy to n‐In0.53Ga0.47As Layer

This paper presents a Tb/Ni/TiN stack that can act as a metallic contact for n‐In0.53Ga0.47As layer with lower specific contact resistivity. Tb/Ni/TiN layers are deposited sequentially on n‐In0.53Ga0.47As via sputtering and Ni(Tb)‐InGaAs alloy is formed using rapid thermal annealing. The ultralow specific contact resistivity (ρc) of 7.98 × 10−9 Ω cm2 is obtained between Ni(Tb)‐InGaAs and n‐In0.53Ga0.47As layers, which is more than two orders of magnitude lower than that of a control sample with a Ni/TiN stack. The increased dopant concentration in the Ni‐InGaAs alloy and the lowered barrier height between Ni‐InGaAs and n‐In0.53Ga0.47As are considered to be possible reasons for the improved contact resistance. The Tb/Ni/TiN stack is promising as a metallic contact for metal‐oxide‐semiconductor field‐effect transistors (MOSFETs) based on n‐In0.53Ga0.47As layer. A Ni‐Tb‐InGaAs alloy formed by Tb/Ni/TiN stack demonstrates ultralow contact resistance to n‐In0.53Ga0.47As. The extracted specific contact resistivity (ρc) is as low as 7.98 × 10−9 Ω cm2, which is more than three orders of magnitude lower than that of a Ni/TiN stack without a Tb interlayer. The Ni‐Tb‐InGaAs contact seems to be promising to satisfy the requirement of ρc in future InGaAs devices.