The effects of surface states and series resistance on the performance of Au/SnO sub(2)/n-Si and Al/SnO sub(2)/p-Si (MIS) Schottky barrier diodes

We have fabricated two types of Schottky barrier(SBDs),Au/SnO sub(2)/n-Si (MIS1) and Al/SnO sub(2)/p-Si (MIS2), to investigate the surface (N sub(s)s and series resistance (R sub(s) effect on main electrical parameters such as zero-bias barrier height ([Phi] sub(Bo)) and ideality factor (n) for these SBDs. The forward and reverse bias current-voltage (I-V) characteristics of them were measured at 200 and 295 K, and experimental results were compared with each other. At temperatures of 200 and 295 K, [Phi] sub(Bo), n, N sub(ss) and R sub(s) for MIS1 Schottky diodes (SDs) ranged from 0.393 to 0.585 eV, 5.70 to 4.75, 5.42x10 super(13) to 4.27x10 super(13) eV super(-1) cm super(-2) and 514 to 388 [Omega], respectively, whereas for MIS2 they ranged from 0.377 to 0.556 eV, 3.58 to 2.1, 1.25x10 super(14) to 3.30x10 super(14) eV super(-1) cm super(-2) and 312 to 290 [Omega], respectively. The values of n for two types of SBDs are rather than unity and this behavior has been attributed to the particular distribution of N sub(ss) and interfacial insulator layer at the metal/semiconductor interface. In addition, the temperature dependence energy density distribution profiles of N sub(ss) for both MIS1 and MIS2 SBDs were obtained from the forward bias I-V characteristics by taking into account the bias dependence of effective barrier height ([Phi] sub(e)) and R sub(s). Experimental results show that both N sub(ss) and R sub(s) values should be taken into account in the forward bias I-V characteristics. It has been concluded that the p-type SBD (MIS2) shows a lower barrier height (BH), lower R sub(s), n and N sub(ss) compared to n-type SBD (MIS1), which results in higher current at both 200 and 295 K.