Active-matrix nc-Si electron emitter array for massively parallel direct-write electron-beam system

Abstract

This paper presents our designed and prototyped structure of electron emitter array integrated with an active-matrix driving LSI for high-speed massively parallel direct-write electron-beam (e-beam) system. In addition, the validation results of its performance as an electron source for massively parallel operation are described. Electron source used in this system is nanocrystalline Si (nc-Si) ballistic surface electron emitter where 1:1 projection of e-beam has been demonstrated to resolve patterns of 30 nm in width in our previous work. Electron emitting part of the device consists of arrayed dots of nc-Si emitter fabricated on SOI or Si substrate, and TSV (Through Silicon Via) plugs connected to the dots from back side of the substrate. Forming an aligned joint of the TSV plugs with driving pads on the active-matrix LSI constitutes the device. Electron emission is driven by the LSI operation, boosted up to appropriate level by the builtin voltage level shifter, in accordance with a bitmap image preliminarily stored in an embedded memory. Electron emission from a test structure of arrayed dot patterns of nc-Si emitter worked in practice, showing the possibility to switch on and off the beamlets by changing CMOS-compatible voltage.