We have built a novel oblique angle scatterometer designed and optimized for measurements of rough surfaces having a root mean square roughness value (RMS Roughness) on the order of 100 nm – 1000 nm or larger. The majority of existing techniques for measurement of such surfaces are slow, sensitive to vibration, provide short or no working distance, may result in generation of particles and have very small throughput.1 In this paper, we novel metrology addressing the above limitations.
A large numerical aperture (NA in range 0.65-0.8), diffraction limited, broadband (100 nm - 30,000 nm), all-reflective
confocal microscope objective design is discussed. The design is compatible with engineered polarization state of the
excitation beam further decreasing focus spot size. Unlike in the other designs in the proposed system measured sample
does not obscure final reflector. The proposed objective extends spatial and temporal limits of existing novel optical
microscope techniques such as confocal microscopy described, multi-photon microscopy, 4Pi microscopy, I5M
microscopy and others. All reflective design gives promise for high power and high resolution laser-machining