Al/Si/Pd Ohmic contact to n-GaP based on the solid phase regrowth principle

We report the study of an Al/Si/Pd contact scheme, derived from the Si/Pd contact scheme reported previously based on the solid phase regrowth principle, to n-GaP. The Al overlayer was employed to reduce the contact resistivity. Contact resistivity of low 10⁻⁵ Ω-cm² has been obtained. The contact resistivity virtually remained unchanged after aging at 550 °C for up to 25 hours. The ohmic contact formation mechanism can be rationalized in terms of the solid phase regrowth (SPR) principle and the solid phase epitaxy of Si on n-GaP. With such a superior thermal stability, the Al/Si/Pd contact would be a suitable contact candidate for GaP-based device application.