Characterization of rapid thermally grown dielectrics by surface charge analysis and atomic force microscopy

Abstract

With the advent of Rapid Thermal Processing to produce gate dielectrics, the need for quick characterization of the dielectrics has increased. The effect of the process conditions on the dielectric quality need to be considered during process development. Pre-growth cleaning processes may also affect the quality of the dielectric material. Surface Charge Analysis (SCA) and Atomic Force Microscopy (AFM) provide measurements that may be used to aid process development. In this work, SCA and AFM have been used to examine the effects of NH<SUB>4</SUB>OH:H<SUB>2</SUB>O<SUB>2</SUB>:H<SUB>2</SUB>O cleaning on (100) silicon wafers. The data indicate a correlation between surface roughness and interface trap density, with rougher surfaces having lower densities of interface traps. Also included in this work is a SCA comparison of oxides grown using Rapid thermal Oxidation in O<SUB>2</SUB> and N<SUB>2</SUB>O ambients.