Dose monitoring in MeV energy hydrogen implanted silicon by photo-modulated reflectance measurements

Proton implantation into silicon is utilized for several purposes in semiconductor industry. Low dose implantations can be applied in power electronic devices to fine tune the minority charge carrier lifetime [1] , while medium dose proton implants generate hydrogen related donor states and are used for creating n-type regions in the sample [2] . High-energy, low-mass hydrogen ions generate orders of magnitude lower defect levels as compared to the heavier B + , P + , or As + dopant implants, due to their deep penetration to several tens of microns and low nuclear stopping cross-section for silicon atomic nuclei. Defect-related implantation dose monitoring for MeV-energy proton implants requires non-destructive high sensitivity characterization techniques for technology control. Besides low level damage monitoring, on a longer time scale after the implantation process, the relaxation and reconfiguration of the dilute defect structure in the near surface region, as well as changes in the depth distribution of hydrogen atoms and their interaction with generated defects at around the deep ion projected range are also of intensive interest in technology control and industrial applications.