Detection of Vacancy Distributions by Decoration with Hydrogen

Abstract

A well-known method for the determination of vacancy distributions in silicon is based on the decoration of vacancies with in-diffused platinum and subsequent profiling of the Pt-distribution with DLTS analysis. The vacancy profile can then be correlated with the substitutional Pt profile. However, there are significant drawbacks of this method: The in-diffusion of platinum is a high-temperature step, which already can alter the vacancy profile; moreover, DLTS measurements with a suitable depth resolution are time-consuming and difficult. Therefore, it is proposed in this paper to decorate the vacancies with hydrogen by processes finally resulting in the formation of vacancy- and hydrogen-related donor and acceptor states. The determination of such doping profiles and by this the detection of vacancy distributions can be easily enabled by depth-resolved spreading resistance measurements with a very good spatial resolution. Hydrogen atoms for the decoration of vacancies can be incorporated by plasma exposure or ion implantation.