Improvements of the PLD (Pulsed Laser Deposition) method for fabricating photocathodes in ICMOS (Intensified CMOS) sensors

摘要

We introduce new technologies improving the PLD (Pulsed LaserDeposition) method to fabricate visible (370 ～ 600 nm) and NUV (NearUltraviolet, 185 ～ 320 nm) photocathodes for IIT (Image Intensifier Tube)sensors. The multi-purpose PLD VC (Vacuum Chamber) by utilizing opticalwindow viewports and a couple of internal carousels can do the whole processof the laser deposition of various alkalis, including the measurement the QE(Quantum Efficiency) in-situ, for multiple photocathode targets. Then, we haveintegrated a Load/Degassing/Assembly (LDA) VC to the PLD VC, to prepare,load, degas, and assemble the alkali targets and the photocathode substrates.With these facilities, we have manufactured high QE photocathodes free fromoxidation and water vapor contamination during the process. In this paper, wedescribe detail procedures of our new technologies to make S20 and CsTephotocathodes for visual and NUV wavelengths respectively, and discuss aboutthe test results of the IIT products.