Tellurium Doped p-n Device Fabrication by Thermal Diffusion on GaSb-VDS-Substrate

The III-V compound semiconductors exhibit the advantage of wide bandgap and high electron mobility, making them appropriate for optoelectronics and microelectronics sector. Vertical directional solidification (VDS) is a technique developed to grow the high quality III-V semiconducting bulk crystals. One of the Sb based III-V materials, Gallium Antimonide (GaSb) was grown by VDS. This direct band gap semiconductor was realized as a ρ-type substrate and thermally diffused in vacuum by Tellurium (Te) ions as n-type dopant to fabricate ρ-n junction. Fabrication of successful ρ-n junction was confirmed by its electrical behaviour. It was later subjected to furnace annealing in vacuum at 200°C and 400°C for dopant to compensate deep in crystal geometry. Rectification characteristics of this junction were distinctly sharp for either biasing. It is revealed that rectification was approaching to optimum ideality factor (1-2) after vacuum furnace annealing at higher temperature. This device exhibits an applicability for NIR sensing close to 1.7 µm.