Local synthesis of aligned carbon nanotube bundle arrays by using integrated micro-heaters for interconnect applications

A rapid synthesis process for local growth of the aligned carbon nanotube (CNT) bundle arrays in a quartz tube operated at room temperature is reported. The CNT bundles of 105 μm in length and 130 μm in diameter were thermally and locally synthesized on the wafer areas where the micro-heaters were integrated on the opposite side. The micro-heaters can reach a temperature of about 720 0C in the localized areas for the CNT growth while the temperature in the non-heating areas remains below 400 0C, which prevents damage to the integrated circuits (ICs) located in those areas. Furthermore, exact control of the CNT growth length is possible by varying the voltage supply time to the micro-heater since the processing wafer can be heated up and cooled down very rapidly due to its small mass. The resistivity of CNT bundles was measured to be 0.009 57 Ω cm, obtained from a nearly linear current-voltage characteristic. Hence, these locally grown CNT bundle arrays could find potential applications in three-dimensional (3D) IC wafer-level packaging.