Temperature dependent electrical characteristics of rectifying graphitic contacts to p-type silicon

Abstract

Graphitic contacts to semiconductors have been shown to provide highly rectifying current–voltage characteristics coupled with high thermal/chemical stability. Energetically deposited graphitic contacts to p-type Si have exhibited rectification ratios (at ±1.0 V) up to 106:1 and ideality factors approaching unity. Here, we report temperature dependent current–voltage (I–V–T) measurements performed on such devices. The measurements and subsequent analysis show that during energetic carbon deposition, deleterious oxide/contaminants are removed from the Si substrate surface. The Richardson constant of the p-type Si extracted from the I–V–T measurements agrees with the theoretical value, indicating that the surface contaminants are removed without significant damage to the underlying Si. Therefore, by energetic deposition of C on Si, C–Si junctions can be formed with low lateral inhomogeneity and low interface defect density. These attributes of the junctions enable the observed near-ideal Schottky diode characteristics.