We report an Ohmic contact to lightly doped (5× 1017 cm-3) n-In 0.53 Ga0.47 As with a specific contact resistance of =2.6× 10-8± 1.7× 10 -8Ω-cm2, rivaling the lowest reported values on n-In0.53 Ga0.47 As with significantly higher original dopant concentrations (>1× 1019 cm-3) than the epilayer used in this letter. This reduction of ρc was achieved using the combination of a Pd/Si-based solid phase regrowth (SPR) contact with an ammonium sulfide surface treatment before contact deposition. Transmission electron microscopy confirmed that the SPR mechanism still occurred when the ammonium sulfide treatment was used. Both the SPR and sulfide-treated SPR cases reduced ρc versus a Pd/Ti/Au contact. For comparison, a sulfide-treated Pd/Ti/Au contact that does not undergo SPR was fabricated, and it did not have a lower c compared with the same contact without the sulfide treatment. This discrepancy indicates that SPR is essential for benefiting from the sulfide treatment.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Electrical and Electronic Engineering