On electrical and interfacial properties of iron and platinum Schottky barrier diodes on (111) n-type Si0.65Ge0.35

Abstract

Current–voltage (I–V), capacitance–voltage–frequency (C–V–f) and conductance–voltage–frequency (G/[Formula: see text]–V–f) characteristics of Molecular Beam Epitaxy (MBE)-deposited Fe/n-Si[Formula: see text]Ge[Formula: see text] (FM1) and Pt/[Formula: see text]-Si[Formula: see text]Ge[Formula: see text](PM2) (111) orientated Schottky barrier diodes (SBDs) have been investigated at room-temperature. Barrier height ([Formula: see text]), ideality factor (n) and series resistance (R[Formula: see text]) were extracted. Dominant current conduction mechanisms were determined. They revealed that Poole–Frenkel-type conduction mechanism dominated reverse current. Differences in shunt resistance confirmed the difference found in leakage current. Under forward bias, quasi-ohmic conduction is found at low voltage regions and space charge-limited conduction (SCLC) at higher voltage regions for both SBDs. Density of interface states (N[Formula: see text]) indicated a difference in interface reactivity. Distribution profiles of series resistance (R[Formula: see text]) with bias gives a peak in depletion region at low-frequencies that disappears with increasing frequencies. These results show that interface states density and series resistance of Schottky diodes are important parameters that strongly influence electrical properties of FM1 and PM2 structures.