Characterization of a Real-time Confocal Scanning Optical Microscope

The suitability of the Real-time Confocal Scanning Optical Microscope (RSOM) for semiconductor process metrology had not previously been examined. Recent improvements in the RSOM have enabled us to make precise measurements on weakly reflecting sub-micron geometries. Data will be presented to demonstrate the lateral and depth resolution of the improved microscope, which will be compared to theoretically predicted results. Preliminary data from critical dimension measurements of photoresist on silicon, and photoresist on silicon dioxide wafers, for linewidths in the range of 0.7 to 2.6μm will also be presented.