Fabrication and characterization of ultra thin Si0₂ for nano devices: surface morphology and electrical study

Abstract

The aim of this research is to fabricate and characterize (optical and electrical) an ultra thin silicon dioxide for sub nano devices. In this research, dry oxidation method using high temperature furnace is chosen to fabricate a thin layer of oxide below 30Angstroms. There are three level of temperature used. that is 7S0, 800 and 8S(/C. The wqfers were grown in 0.333 litre/min. 0,667 liter/min and 1.00 literlmin oxygen flow rate with variation in growth time 1, 2 and 3 minutes. Thicknesses were obtained using ellipsometer and the surface topography and were achieved using atomic force microscope (UM). Parameters and data has been interpreted using Taguchi's method. This is to analyze the most affecting factors in producing an ultra thin silicon dioxide. Taguchi's method were able to predict the thicknesses for each combination of parameters. Results show that the temperature is the most effecting factor that effects the growth of oxide. Results also show that oxygen flow rates do have an influence to the thicknesses and surface properties. A higher amount of flow rate (illmin) will increase the oxide thickness and also will create a smooth oxide surface. There are also results of a high frequency CV and IV techniques were employed as for the devices electrical characterizations. The CV results shows that there is a shift in VFB for all the wafers and IV shows that breakdown occurs at 1 MV/cm.