ABSTRACT
A new finishing method was developed to correct the thickness distribution of a quartz crystal wafer by the numerically controlled scanning of a localized atmospheric pressure plasma. The thickness uniformity level of a commercially available AT-cut quartz crystal wafer was improved to less than 50 nm without any subsurface damage by applying one correction process. Furthermore, applying a pulse-modulated plasma markedly decreased the correction time of the thickness distribution without breaking the quartz crystal wafer by thermal stress.
Subject(s)
Micro-Electrical-Mechanical Systems/instrumentation , Quartz/chemistry , Transducers , Atmospheric Pressure , Equipment Design , Equipment Failure Analysis , Gases/chemistry , Hot Temperature , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Local wet etching technique was proposed to fabricate high-performance aspherical mirrors. In this process, only the limited area facing to the small nozzle is removed by etching on objective surface. The desired objective shape is deterministically fabricated by performing the numerically controlled scanning of the nozzle head. Using the technique, a plano-elliptical mirror to focus the neutron beam was successfully fabricated with the figure accuracy of less than 0.5 microm and the focusing gain of 6. The strong and thin focused neutron beam is expected to be a useful tool for the analyses of various material properties.
