Thermally grown indium (In) thin-film for creating ohmic contact and In-bumps for HgCdTe-based IR detectors

• Indium (In) thin films were grown on HgCdTe substrate for ohmic contact formation. • Thermal evaporation technique was applied to grow thin film. • In film of excellent surface morphology and purity were achieved. • Electrical/microstructural properties of the film were explored via TLM and bumps structures. • In could be a suitable metal to form an ohmic contact and bumps in HgCdTe IR detectors. Indium (In) thin films over the mercury cadmium telluride (HgCdTe) substrate were grown employing the thermal evaporation method. Various techniques, namely X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray, atomic force microscopy, and current-voltage (I-V) were employed to investigate the developed films. The tetragonal phase (bcc lattice) of the In films was recognized with a maximum growth along with preferred orientation (1 0 1). The desired elemental composition and purity of In were realized. Uniform, dense and non-porous In film with low roughness was achieved. The films with desired features (film height, particle size, and minimum grain boundaries) were realized by SEM analysis. The optimized indium films were further used to fabricate In bumps/n-HgCdTe structure and Transfer length method (TLM) structure (with a configuration of In/n/p-HgCdTe). The thermally grown indium-bumps having the microstructural properties (desired film height & particle size, bumps with uniform dia and height, etc.) were established. In metal contacts exhibited ohmic behavior with a specific contact resistance ρ c = 5.96 × 10 −4 Ω∙cm 2 . Thus, In could be applied as the most appropriate material for creating the ohmic n-contact and indium-bumps in HgCdTe-based IR detectors.