Investigation of Pd–InGaAs for the formation of self-aligned source/drain contacts in InGaAs metal–oxide–semiconductor field-effect transistors

The formation of salicide-like source/drain contacts on III–V MOSFETs necessitates a search for suitable metals that can react with III–V materials to form ohmic contacts with low sheet resistance and contact resistivity. To advance this search, the reaction between Pd and In0.53Ga0.47As is explored in this work. Reaction temperatures ranging from 200 to 400 °C were investigated, and extensive physical and electrical characterization was performed. Pd completely reacts with In0.53Ga0.47As after annealing at temperatures as low as 200 °C for 60 s to form a very smooth and uniform Pd–InGaAs film with good interfacial quality. Pd–InGaAs formed at 250 °C was found to have a work function of ∼4.6 ± 0.1 eV, sheet resistance of ∼77.3 Ω/square for a thickness of 20 nm, and contact resistivity of ∼8.35 × 10−5 Ω cm2 on In0.53Ga0.47As with n-type active doping concentration of ∼2 × 1018 cm−3. With further development, Pd–InGaAs could potentially be useful as self-aligned contacts for InGaAs transistors.

► Pd reacts completely with In0.53Ga0.47As at 200 °C to form Pd–InGaAs.
► Pd–InGaAs film has good smoothness, uniformity, and interfacial quality.
► Pd–InGaAs formed at 250 °C has a work function of ∼4.6 ± 0.1 eV.
► 20-nm-thick Pd–InGaAs formed at 250 °C has sheet resistance of ∼77.3 Ω/square.
► Pd–InGaAs (250 °C) on n-In0.53Ga0.47As (∼2 × 1018 cm−3) has ρc of ∼8.35 × 10−5 Ω cm2.