HIGH RESOLUTION INTERFEROMETRIC OPTICAL PROFILER FOR SUBMICRON LINEWIDTH MEASUREMENTS

OPTICAL INSTRUMENTS FOR PERFORMING LINEWIDTH MEASUREMENT OR FOR FINDING THE GEOMETRY OF SMALL FEATURES ARE LIMITED BY THE RESOLUTION ASSOCIATED WITH THE WAVELENGTH OF LIGHT. BASIC OPTICAL THEORY STATES THAT FEATURES SMALLER THAN ONE-HALF OF THE ILLUMINATION WAVELENGTH ARE UNRESOLVABLE. HOWEVER, INFORMATION IS PRESENT IN THE IMAGE ABOUT HIGHER SPATIAL FREQUENCIES THAN GIVEN BY THE OPTICAL RESOLUTION. BY UTILIZING DECONVOLUTION, SUPERRESOLUTION, OR HIGH RESOLUTION MICROSCOPY TECHNIQUES, INFORMATION ABOUT HIGHER SPATIAL FREQUENCIES MAY BE EXTRACTED. THE AIM OF THIS RESEARCH IS TO INVESTIGATE TECHNIQUES OF OBTAINING ACCURATE SUBMICRON LINEWIDTH MEASUREMENT FOR IMPLEMENTATION IN AN INTERFEROMETRIC OPTICAL PROFILER WITH THE HOPE OF MEASURING FEATURES ON THE ORDER OF 0.1 MUM IN EXTENT. AN APPLICABLE TECHNIQUE WOULD BE USEFUL IN A COMMERCIAL PRODUCT. POSSIBLEAPPLICATIONS INCLUDE THE MEASUREMENT OF INTEGRATED CIRCUIT OR INTEGRATED OPTICAL DEVICE GEOMETRIES AS WELL AS MEASUREMENT OF PITS IN COMPACT DISK MASTERS, AND MAGNETIC RECORDING HEAD GEOMETRY.