Reliability Prediction of Highly Scaled MOSFET Devices via Fractal Structure of Spatial Defects

The needs for continuous size reduction of metal-oxide-semiconductor field effect transistor (MOSFET) devices can cause serious reliability concerns. In particular, gate oxide breakdown is a key mechanism concerning the lifetimes of MOSFET devices. In this paper, several spatial point processes are employed to represent general patterns of defect generation in gate oxide. By defining oxide breakdown as a creation of conduction path connecting two oxide interfaces by overlapped defects, percolation models are discussed to predict reliability of MOSFET devices in terms of critical defect density. In the final, we proposed a method to evaluate lifetimes of area-scaled gate oxides in MOSFET devices mainly through their fractal structure. The method suggests an easy way to predict the lifetimes of the devices with area-scaled gate oxides by examining their fractal structure through a fractal dimension without involving breakdown distributions of gate oxides with different areas.