In this paper, firstly a new electron beam production method (vacuum nano-electronics) is introduced. Secondly, various phenomena when an electron beam irradiates at solid materials are reviewed. And recent application technologies of electron beam are explained.
Two different types of compact low energy electron emitters have been developed for the sterilization of plastic drink containers. One is called ITB (In the bottle), and has an electron window of 10 mm in diameter at the nozzle end and can irradiate directly onto interior surfaces of a bottle. The other is called OTB (Outside the bottle), and has 400 mm length electron window for irradiating outside the bottle. Using low electron energy below 150 kV the harmful effect of containers being affected by thermal distortion, charging and fragrance, etc. can be avoided. We present dosimetric mapping of both emitters for plastic container. The measured values of the dose ranged from a few to several tenths of kGy. These experimental indicates that it helps to provide the information about process parameters and dose of emitters verified experimentally are found to be suitable for a sterilization system. The compact size and the light weight of low energy emitters have also advantages for sterilization system of the plastic container.
Fabrications of gated field emitter array (FEA), such as Si-FEA and Spindt-type FEA, is overviewed from the conventional method to the latest one. The invention of an etch-back method makes it possible to form the gate electrode on the emitter tip, irrespective of the emitter shape, and also possible to form the multi-stacked gate electrode for beam focusing. A hafnium carbide coating can enhance the electron emission and emission lifetime, significantly. The historical Spindt-type FEA fabrication is also progressing. Using a double-layered photoresist, instead of aluminum parting layer, makes it possible to apply the multi-gate formation even on the Spindt-type FEA. These FEAs are applicable for many kinds of attractive devices, such as ultra-high sensitive image sensor, radiation tolerant electronics, and stationary X-ray source for medical applications.
This review describes novel applications of field emitter arrays. Firstly, the advantages of the field emitter arrays are described on the basis of theoretical arguments on the field electron emission. Secondly, typical characteristics of the vacuum triode are shown. Because an electron beam in vacuum is affected neither by temperature variations of the environment nor by radiation, field emitter arrays are expected to be used under high and/or low temperatures, and also in radiation field. Novel applications of field emitter arrays including radiation tolerant image sensor, charge neutralizer for ion implanter, and electron source for lighting device are described.