Development of MEMS pierce-type nanocrystalline Si electron-emitter array for massively parallel electron beam direct writing

This paper mainly reports the process development of a Pierce-type nanocrystalline Si (nc-Si) electron emitter array for massively parallel electron beam (EB) lithography based on active-matrix operation using a large-scaled integrated circuit (LSI). The emitter array consists of 100×100 hemispherical emitters formed by isotropic wet etching of Si. EB resist patterning was demonstrated by 1:1 projection exposure using a discrete emitter array at CMOS-compatible operation voltages. To independently control each emitter using the LSI, isolation trenches filled with benzocyclobutene (BCB) were fabricated in the Si substrate. In addition, the integration process of the emitter array, the LSI and an extraction electrode plate was developed based on Au-In and polymer bonding technologies.