Sub 20 nm Short Channel Carbon Nanotube Transistors

Short channel (~80 nm) n-type single-walled carbon nanotube (SWNT) field-effect transistors (FETs) with potassium (K) doped source and drain regions and high-k gate dielectrics (ALD HfO2) are obtained. For nanotubes with diameter ~ 1.6 nm and bandgap ~ 0.55 eV, we obtain n-MOSFET-like devices exhibiting high on-currents due to chemically suppressed Schottky barriers at the contacts, subthreshold swing of 70mV/decade, negligible ambipolar conduction and high on/off ratios up t...

Choosing a suitable doping level of channel relevant to channel diameter is considered for determining the carbon nanotube field effect transistors' performance which seem to be the best substitute of current transistor technology. For low diameter values of channel the ratio of on/off current declines by increasing the doping level. But for higher diameter values there is an optimum point of doping level in obtaining the highest on/off current ratio. For further verification...

We describe a robust technique for the fabrication of high performance vertically scaled n-doped field-effect transistors from large band gap carbon nanotubes. These devices have a tunable threshold voltage in the technologically relevant range (-1.3V < V_th < 0.5V) and can carry up to 5-6 muA of current in the on-state. We achieve such performance by exposure to potassium (K) vapor and device annealing in high vacuum. The treatment has a two-fold effect to: (i) controllably ...

High performance enhancement mode semiconducting carbon nanotube field-effect transistors (CNTFETs) are obtained by combining ohmic metal-tube contacts, high dielectric constant HfO2 films as gate insulators, and electrostatically doped nanotube segments as source/drain electrodes. The combination of these elements affords high ON currents, subthreshold swings of ~ 70-80 mV/decade, and allows for low OFF currents and suppressed ambipolar conduction. The doped source and drain...

A simple method combining photolithography and shadow (or angle) evaporation is developed to fabricate single-walled carbon nanotube (SWCNT) devices with tube lengths L~10-50 nm between metal contacts. Large numbers of such short devices are obtained without the need of complex tools such as electron beam lithography. Metallic SWCNTs with lengths ~ 10 nm, near the mean free path (mfp) of lop~15 nm for optical phonon scattering, exhibit near-ballistic transport at high biases ...

Carbon nanotube field-effect transistors (CNT FETs) are regarded as promising candidates for next-generation energy-efficient computing systems. While research has employed the lift-off process to demonstrate the performance of CNT FETs, this method now poses challenges for enhancing individual FET performance and is not suitable for scalable fabrication. In this paper, we summarize the limitations of the lift-off process and point out that future advancements in manufacturin...

Single electron transistors (SETs) made from single wall carbon nanotubes (SWCNTs) are promising for quantum electronic devices operating with ultra-low power consumption and allow fundamental studies of electron transport. We report on SETs made by registered in-plane growth utilizing tailored nanoscale catalyst patterns and chemical vapor deposition. Metallic SWCNTs have been removed by an electrical burn-in technique and the common gate hysteresis was removed using PMMA an...

Although printed transistors have a wide range of applications, the limited resolution of printing techniques (10-30 um) has been a barrier to advancement and scaling, particularly down to submicron dimensions. While previous works have shown creative approaches to realizing submicron channel lengths with printing, reliance on chemical processes unique to specific inks or tedious post-processing limit their applicability. Here, we report the use of capillary flow printing (CF...

Single-walled carbon nanotubes (SWNTs) have been grown via chemical vapor deposition on high-kappa dielectric SrTiO3/Si substrates, and high-performance semiconducting SWNT field-effect transistors have been fabricated using the thin SrTiO3 as gate dielectric and Si as gate electrode. The transconductance per channel width is 8900 S/m. The high transconductance cannot be explained by the increased gate capacitance; it is proposed that the increased electric field at the nanot...

A fresh look on carbon-based transistor channel materials like single-walled carbon nanotubes (CNT) and graphene nanoribbons (GNR) in future electronic applications is given. Although theoretical predictions initially promised that GNR (which do have a bandgap) would perform equally well as transistors based on CNTs, experimental evidence for the well-behaved transistor action is missing up to now. Possible reasons for the shortcomings as well as possible solutions to overcom...