Optical densitometry as a monitor for sub 5 keV implants

As the minimum implant energies for semiconductor processing continue to fall below 5 keV new ion implant tool sets are being placed into production that cannot be monitored in-line effectively at these lower energies with standard metrology methods. Optical densitometry may provide an economical solution to monitoring these ultra low energy implanters. This study consists of implants at energies from 0.50 keV to 5 keV at a dose of 5E14 ions/cm² for both boron and arsenic. A summary of these measurements is included as well as an assessment of the accuracy and sensitivity of optical densitometry