Photoelectrochemically Etched Microchannel Plates

The microchannel plate (MCP) is one of the most important components in spectroscopic systems for characterization of deep space radiation such as the Extreme Ultraviolet Explorer. The MCP requires an array of high aspect ratio channels in a substrate with conductors on the front and back faces. We propose a novel, potentially rapid and highly economical method for fabricating these structures using light-driven etching of silicon wafers. The method promises to provide holes <10 um wide and with <5 um walls, structures which cannot be achieved using presently known chemical etching techniques. The availability of MCPs with such high resolution channels and high fraction of channel to wall space will enable much improved resolution over current cored glass MCPs. Phase I will have the objective of demonstrating the feasibility of photoelectrochemical etching of 10 x 10 um square holes through a 50 um single crystal Si wafer and establishing the minimum wall width for a favorable set of photoelectrochemical etching parameters. Phase II would then be directed at perfecting the process, extending it to larger areas, and to processing the MCPs into full image intensifiers.