An optically switchable emitter array with carbon nanotubes grown on a Si tip for multielectron beam lithography.

In this paper we report the design, fabrication and evaluation of a field emitter array of carbon nanotubes (CNTs) on a Si tip with a pn junction. Electron beam emission can be switched on by laser irradiation. The Si tip array is formed on a 5 µm-thick Si membrane. Each emitter consists of CNT emitter tips and a gate electrode. On the apex of the Si tip, CNTs are grown in order to emit electrons at a low extraction voltage. Additionally, the pn junction is formed into emitter tips. Optical switching of an array consisting of nine emitters is demonstrated. The electron beam switching is synchronized with laser irradiation successfully. The emission current and its on/off ratio are approximately 40 nA and 4.