Scalable Fabrication of Ambipolar Transistors and Radio-Frequency Circuits Using Aligned Carbon Nanotube Arrays

摘要

Electronic devices based on carbon nanotubes (CNTs) have attracted significant attention for potential radio frequency (RF) applications. It has been shown that intrinsic current-gain and power-gain cutoff frequencies (ƒ_T and ƒ_(max)) above 1 THz should be possible, but experimental demonstration using field-effect transistors (FETs) based on individual CNTs has suffered from excessive parasitic effects and impedance mismatch prob-lems. In order to overcome these limitations, great efforts have been concentrated on FETs made from aligned arrays of CNTs. Since all of the published A-CNT RF circuits were designed to work in the linear region, it is often stated that it is necessary to use dense arrays of all-semiconducting nanotubes to achieve high performance. While impressive progress has been made in achieving high-density arrays of CNTs, for example in several cases the required density of tens of nanotubes per micrometer has been realized, it is still challenging to eliminate all metallic CNTs without damaging semiconducting CNTs and thus severely degrading the performance of the CNT-array FETs.