The role of interface states and series resistance on the Ⅰ-Ⅴ and C―V characteristics in Al/SnO_2/p-Si Schottky diodes

摘要

In order to good interpret the experimentally observed non-ideal Al/SnO_2/p-Si (MIS) Schottky diode parameters such as the barrier height Φ_B, series resistance R_s and density of interface states N_(SS), a calculation method has been reported by taking into account interfacial oxide layer and ideality factor n in the current transport mechanism. The current -voltage (Ⅰ-Ⅴ) and capacitance-voltage (C-V) characteristics of MIS diodes are studied over a wide temperature range of 80 350 K. The effects of R_s, interfacial layer and N_(ss) on Ⅰ-Ⅴ and C-V characteristics are investigated. The values of n were strongly temperature dependent and decreased with increasing temperature. The energy distribution of N_(ss) was determined from the forward bias Ⅰ-Ⅴ characteristics by taking into account the bias dependence of the effective barrier height. The mean N_(ss) estimated from Ⅰ-Ⅴ and C-V measurements decreased with increasing temperature. The R_s estimated from Cheung's functions was strongly temperature dependent and decreased with increasing temperature. The Ⅰ-Ⅴ characteristics confirmed that the distribution of N_(ss), R_s and interfacial layer are important parameters that influence the electrical characteristics of MIS devices.