| AVS 57th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Tuesday Sessions |
| Session NS-TuA |
| Session: | Carbon-Based Nanomaterials |
| Presenter: | S. Maeda, Santa Clara University |
| Authors: | S. Maeda, Santa Clara University T. Yamada, Santa Clara University H. Yabutani, Santa Clara University T. Saito, Santa Clara University C. Yang, Santa Clara University |
| Correspondent: | Click to Email |
Carbon nanostructures such as nanotube (CNT) and nanofiber (CNF) are the most promising materials for applications in next-generation silicon integrated circuits. Knowledge of the temperature dependence of these materials is critically important as it relates directly to circuit performance. However, in practice, it is extremely difficult to measure and control the temperature of each test device and maintain thermal equilibrium because of its small thermal capacity. Therefore, one must determine the temperature of test devices by other means. Here we report results of such a study on vertical via and horizontal CNF test devices. CNF can potentially be a replacement for copper in on-chip via interconnects [1], as well as in through-silicon-vias (TSVs) in three-dimensional chips [2,3 ]. The horizontal CNF test device can be used as a prototype of interconnect lines between adjacent transistors in the same silicon layer. In the horizontal structure, the temperature of the CNF is extracted from current stress measurements using our heat transport model [4] . For the via test device, the CNF temperature is estimated from that of the temperature-controlled measurement system [1]. In both cases, the conductivity of CNF is determined from the measured current-voltage characteristics. We find that in either case, the conductivity increases with increasing temperature as expected. However, the measured resistance of the test device in each case contains a very different contact resistance component, due to the much higher contact resistance in the horizontal structure [5]. From the conductivity versus temperature behavior, we extract the activation energy, which turns out to be about 30 meV in each case. This finding suggests that the change in conductivity in CNF, regardless of device configuration, is due to electron trapping and detrapping at defect sites within the carbon nanostructure.
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[4] T. Yamada, T. Saito, D. Fabris, and C. Y. Yang, IEEE Elect. Dev. Lett., 30 (2009) 469.