Device study, chemical doping, and logic circuits based on transferred aligned single-walled carbon nanotubes

Department of Electrical Engineering, University of Southern California, Los Angeles, California 90089, USA
Applied Physics Letters (Impact Factor: 3.52). 08/2008; 93(3):033101 - 033101-3. DOI: 10.1063/1.2956677
Source: IEEE Xplore

ABSTRACT In this paper, high-performance back-gated carbon nanotube field-effect transistors based on transferred aligned carbon nanotubes were fabricated and studies found that the on/off ratio can reach 107 and the current density can reach 1.6 μ A /μ m after electrical breakdown. In addition, chemical doping with hydrazine was used to convert the p -type aligned nanotube devices into n -type. These devices were further utilized to demonstrate various logic circuits, including p -type metal-oxide-semiconductor inverters, diode-loaded inverters, complementary metal-oxide-semiconductor inverters, NAND, and NOR gates. This approach could work as the platform for future nanotube-based nanoelectronics.

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Available from: H.-S. Philip Wong, Jul 28, 2015
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    • "Nevertheless, the high temperature needed for good quality CNT growth is incompatible with current CMOS technologies [10]. Alternatively , various methods for CNT assembly in the post-synthetic regime have been developed [11] [12] [13] [14] [15] [16]. Among then, acdielectrophoresis (DEP) using an ac electric field to integrate CNTs onto pre-patterned electrodes has proven its potential [17]. "
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    • "Hence, chemical doping of nanotubes provides an efficient way to control the electrical properties of CNTFETs. It has been reported that p-type CNTFETs can be converted to n-type via potassium doping [4], by functional groups existing in polymers and molecules [5] [3] [6]. Modulation of nanotube device performance while maintaining its p-type behavior, however, is very important for electronic applications. "
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    • "From Fig. 4(d), after the electrical breakdown, I on /W is 8.3 μA/μm and g m /W is 2.2 μS/μm. Compared with the results from devices fabricated using aligned nanotubes with typical density (5 tubes/μm) reported in our previous publication (I on /W = 1.7 μA/μm and g m /W = 0.28 μS/μm) [24], the values of I on /W and g m /W reported here are 5 times and 8 times better, respectively. The improvements are due to both the higher nanotube density and the adoption of a high-κ gate dielectric. "
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