In-situ real-time depth profiling by elastic recoil detection and its application to ion nitriding of stainless steel

A dual beam experiment has been set up combining real-time depth profiling and low energy ion implantation in order to study the kinetics of ion nitriding. The choice of low energy ion implantation allows precise and independent control of the important ion nitriding parameters ion energy, ion current density, temperature and residual gas composition. Real-time depth profiling is achieved by Elastic Recoil Detection (ERD) using an angle resolving ionization chamber telescope detector. A large solid angle (5.4 msr) allows a fast data acquisition and hence real-time depth profiling with a time resolution of about 30 s combined with a depth resolution of about 10 nm. The capabilities of the setup and its limitations will be discussed. Measurements revealing the role of mechanisms relevant for the nitrogen transport during ion nitriding of stainless steel i.e. diffusion, sputtering, adsorption of oxygen from the residual gas will be presented.