CMOS-Analogous Wafer-Scale Nanotube-on-Insulator Approach for Submicrometer Devices and Integrated Circuits Using Aligned Nanotubes

Abstract

Massive aligned carbon nanotubes hold great potential but also face significant integration/assembly challenges for future beyond-silicon nanoelectronics. We report a wafer-scale processing of aligned nanotube devices and integrated circuits, including progress on essential technological components such as wafer-scale synthesis of aligned nanotubes, wafer-scale transfer of nanotubes to silicon wafers, metallic nanotube removal and chemical doping, and defect-tolerant integrated nanotube circuits. We have achieved synthesis of massive aligned nanotubes on complete 4 in. quartz and sapphire substrates, which were then transferred to 4 in. Si/SiO(2) wafers. CMOS analogous fabrication was performed to yield transistors and circuits with features down to 0.5 mum, with high current density approximately 20 muA/mum and good on/off ratios. In addition, chemical doping has been used to build fully integrated complementary inverter with a gain approximately 5, and a defect-tolerant design has been employed for NAND and NOR gates. This full-wafer approach could serve as a critical foundation for future integrated nanotube circuits.

Chirality-controlled synthesis of single-wall carbon nanotubes using vapour-phase epitaxy

“…4a,b, respectively. In brief, the cloned (7, 6) nanotubes grown on quartz substrates were transferred to Si/SiO 2 substrates with 50 nm SiO 2 using methods described in our previous publication 9 . This was followed by formation of Ti/Pd (0.5/50 nm) source/drain metal contacts using lithography and lift-off techniques.…”

“…According to the above analysis, (6,5) tubes should grow five times faster than (9,1). Precise rate measurement is challenging because of the short growth duration and non-synchronized initiation of growth 36 .…”

“…S ingle-wall carbon nanotubes (SWCNTs) possess superior electrical and optical properties, and hold great promise for electronic and biomedical applications [1][2][3][4][5][6][7][8][9][10] . As the electronic property of an SWCNT strongly depends on its chirality, the lack of synthetic control in chirality has long been recognized as a fundamental impediment in the science and application of SWCNTs.…”

High performance semiconducting enriched carbon nanotube thin film transistors using metallic carbon nanotubes as electrodes

“…[1][2][3][4][5][6][7][8][9][10][11] The TFTs fabricated from a network of CNTs can be advantageous to individual nanotube devices as they provide more device to device homogeneity and cover large areas. Since in the CNT TFTs a large number of nanotubes contribute in the transportation of charge simultaneously, the output current can also be significantly increased.…”

High‐Throughput Fabrication of Flexible and Transparent All‐Carbon Nanotube Electronics

“…Notable progress has been made on the large‐scale fabrication of CNT thin films in recent years using floating catalyst chemical vapor deposition (CVD)1, 2, 11 or solution‐processed deposition methods 12, 13, 14. However, due to the lack of techniques that allow the deposition of liquid photoresists on an extremely large scale, CNT‐based electronic devices have been limited to the wafer‐scale12, 15, 16 or medium‐scale integration level 17, 18. Printing technology, such as inkjet printing,19, 20, 21, 22, 23, 24 screen printing,25, 26, 27, 28 and gravure printing,29, 30 in manufacturing electronics has drawn tremendous interest during the past few decades.…”