Calcium fluoride exhibits a fluence dependent transmission behavior at the 193 nm excimer laser wavelength of interest for photolithography applications. The transmission as a function of fluence is determined using a 193 nm excimer laser based transmission measurement system. Different transmission decay rate and saturation level is observed and correlated with structural defects and impurities. Thermally stimulated current measurements are applied to identify defects and correlate the relative concentration of mobile anion vacancies with fluence dependent transmission.
We report on the growth of AlGaInP materials on GaAs substrates using solid, elemental phosphorus in a valved cracker source by molecular beam epitaxy (MBE). The two ternaries are found to be of comparable or better quality than material grown by other, more conventional techniques which use phosphine. The successful growth and doping of the quaternary is reported and recent work in the growth of GaInP quantum well (QW) lasers is discussed. Finally, the compatibility of the valved source in growing arsenide/phosphide heterojunctions is demonstrated.
Passive integrated optical components have several advantages over conventional optical components including reduced size and weight, alignment as part of fabrication and integration with planar detectors and electronics. Waveguide lenses are recognized as key components for signal processing and source collimation in integrated optical systems. However, few papers have discussed their application to optical error signal processing for optical recording. Here we present a new type of mode-index waveguide lens used in a half aperture and dual-half aperture format for generating focus and tracking error signals in a test configuration.