Field-effect transistors based on thermally treated electron beam-induced carbonaceous patterns

Abstract

Electron beam-induced carbonaceous deposition (EBICD) derived from residual hydrocarbons in the vacuum chamber has many fascinating properties. It is known to be chemically complex but robust, structurally amorphous, and electrically insulating. The present study is an attempt to gain more insight into its chemical and electrical nature based on detailed measurements such as Raman, XPS, TEM, and electrical. Interestingly, EBIC patterns are found to be blue fluorescent when excited with UV radiation, a property which owes much to sp² carbon clusters amidst sp³ matrix. Temperature-dependent Raman and electrical measurements have confirmed the graphitization of the EBICD through the decomposition of functional groups above 300 °C. Finally, graphitized EBIC patterns have been employed as active p-type channel material in the field-effect transistors to obtain mobilities in the range of 0.2–4 cm²/V s.