Analytical Modeling of the Interaction of Vacancies and Oxygen for Oxide Precipitation in RTA Treated Wafers

Abstract

We have investigated the impact of RTA induced vacancy supersaturation on oxide precipitation based on as much as possible experimental and theoretical values. Oxygen precipitation after RTA processing was found to be controlled by the initial concentration of interstitial oxygen in a sixth power dependency and frozen vacancies just in a cubic dependency. The formation of tensile strained nVO2 clusters seems to be the favored process for coherent nucleation of oxide precipitates. The reduction of interstitial oxygen can be accurately modeled for the temperature range from 1150 {degree sign}C to 1250 {degree sign}C using Ham's theory for precipitate growth and an empirical relation based on nucleation of oxide precipitates by agglomeration of VO2 complexes. During RTA treatments at temperatures {greater than or equal to} 1300 {degree sign}C vacancies seem to be consumed by other processes. Below RTA temperatures of 1150 {degree sign}C, oxide precipitation is dominated by shrunken as-grown precipitate nuclei because as-grown nuclei can be dissolved only at RTA temperatures {greater than or equal to} 1150 {degree sign}C.