A process control method to monitor ion implantation process conditions by measuring the optical properties of a masking material is provided. A patterned masking material may protect underlying regions of a semiconductor substrate from undergoing a chemical or physical change during an ion implantation...http://www.google.com/patents/US6462817?utm_source=gb-gplus-sharePatent US6462817 - Method of monitoring ion implants by examination of an overlying masking material
