High Temperature Characterization of a MIS Schottky Diode Based on Diamond-Like Carbon Nanocomposite Film

Abstract

Many kind of materials have been inserted between metals and semiconductors to obtain metal–interlayer–semiconductor (MIS) Schottky diodes with higher barrier height. It is well known that the interlayer materials have to meet some requirements such as hold on the substrate, thermal stability and wear resistance. In this context, the diamond-like carbon (DLC) films seem good candidates as a material that can fulfill these requirements due to their superior properties. In this study, sulfur doped diamond-like carbon (S-DLC) nanocomposite film was deposited electrochemically, and it was used as an interlayer to fabricate an Au/S-DLC/p-Si MIS Schottky diode. An Au/p-Si metal semiconductor diode was also fabricated for comparison. The electrodeposited S-DLC film was characterized by scanning electron microscopy, Raman spectroscopy and x-ray photoelectron spectroscopy. Temperature dependence of the current–voltage (I–V) characteristic of the diodes was studied in the range of 300–700 K. The ideality factors (n) and barrier heights (Φb) were calculated from the forward bias I–V characteristics. It was observed that both parameters showed temperature dependence. Barrier height values were increased with increasing temperature, while ideality factors values were decreased. The observed non-linearity in Richardson plots were explained by Gaussian distributions of inhomogeneities of barrier heights. Modified Richardson plots were used to obtain actual values of barrier height. It was shown that S-DLC film can be a good candidate for the high temperature diode applications.