Multichannel Carbon-Nanotube FETs and Complementary Logic Gates With Nanowelded Contacts

A high-performance multichannel carbon-nanotube field-effect transistor (MC-CNTFET) has been built by applying an array of parallel nanowelded single-walled carbon nanotubes (SWCNTs) as the channels. The SWCNT channel array with good directional and spatial control was obtained by the ac electric-field alignment of SWCNTs on a specially designed electrode. An ultrasonic nanowelding technique was utilized to achieve the reliable and highly transparent contacts between SWCNT channels and electrodes. Both p- and n-MC-CNTFETs fabricated exhibit high performance. Key transistor performance parameters, transconductance and carrier mobility reach 50.2$muhboxS$and 7160$hboxcm^2cdothboxV^-1cdothboxs^-1$for p-MC-CNTFETs, and 36.5$muhboxS$and 5311$hboxcm^2cdothboxV^-1cdothboxs^-1$for n-MC-CNTFETs, respectively. Using the authors' techniques, complementary inverters with a high gain of up to 31.2 have also been demonstrated.