Fabrication of high aspect ratio structures for microchannel plates

Abstract

Substrates for microchannel plates have been fabricated using Si micromachining techniques. High aspect ratio pores are constructed using reactive ion etching and streaming electron cyclotron resonance etching, and low-pressure chemical vapor deposition (LPCVD). In one process, 40 μm deep pores with 2 μm openings on 4 μm centers are directly etched in Si. Alternatively, pores with aspect ratios of 30:1 are constructed in a low-stress SiNx membrane using a sacrificial template process whereby pillars of Si are etched and then subsequently backfilled with a dielectric using LPCVD.