Gaussian Distribution on Electrical Characteristics of Al/SiO 2 /p-Si Structures

Abstract

The Al/ /p-Si Schottky diodes (39 dots) with native interfacial insulator layer SiO2 were fabricated on the same Si wafer. The current-voltage (I-V) and capacitance-voltage (C-V) characteristics of metal-o xide -semiconductor diodes, which are based on Al/SiO2/p-Si structures, have been measured at room temperature. Barrier height (BH), ideality factor (n) of these diodes has been calculated fro m their experimental forward b ias current-voltage (I-V), reverse bias capaci- tance-voltage. Even though they are identically performed on the same quarter Si wafer, the calculated values of BH, wh ich is obtained from I-V characteristic, have ranged fro m 0.687 to 0.772 eV and ideality factor n fro m 1.903 to 4.48. The values of barrier heights obtained from C -V characteristics range fro m 0.629 to 1.097 eV. It was found that the values of barrier height Φ ������������ obtained C-V characteristics is larger than that of these values fro m I-V characteristics. The experimental values BH distribution obtained from I-V and C -2 -V characteristics have been fitted by Gaussian function and their mean values of BHs have been calculated to be 0.730 and 0.863 respectively. Normal d istribution of ideality factors mean value is 3.160 with standard deviation 0.689. Experimental results show that the interface states at a native insulator layer between metal and semiconductor play an important role in the value of the BH, ideality factor and the other electrical parameters of Schottky diodes.