This is Phase II of an SBIR project to improve integrated circuit metrology. The need to enhance critical dimension measurement and quality control will become acute in the next few years as integrated circuit features begin to approach the .25 micron size. This project is to use numerical inverse scattering theory with laser interferometry to overcome some of the problems associated with conventional metrology. The feasibility of this approach was demonstrated during Phase I of the grant and a prototype Numerical Microscope is currently being developed.