Next Generation Computing Using Novel Ambipolar Carbon Nanotubes

NU 2016-047

 

Inventors

Mark Hersam*

Alan Sahakian

Michael Geier

Joseph Friedman

 

Short Description

Novel cascaded ambipolar logic family structures for higher efficiency computing

 

Abstract

Increasing computer hardware efficiency for next generation computing requires robust scaling of Si complementary metal oxide semiconductor (CMOS) field effect transistor (FET) logic circuits. However, physical limits of CMOS scaling necessitate improvements of internal hardware like the switching devices and logic structures. Single-walled carbon nanotubes (CNTs) are particularly attractive FETs due to their efficiency and ability operate at higher voltage ranges. The majority of efforts have been applied to the use of CNT FETs as unipolar electrical switches with one addressable gate. The use of two independently addressable gates for ambipolar FETs has been proposed, but resulting structures have been highly complex, less efficient, and expensive to fabricate. Northwestern engineers have developed a novel cascaded logic family that exploits ambipolar FETs in a different way. They propose the use of a common back gate that can be shared by complementary pairs of ambipolar FETs, decreasing the device count by 50%-75%. This adjustment leads to significant computing improvements related to power and speed, providing the ability to perform complex computations with fewer devices and logic stages. The design and fabrication are also simplified as bottom and top gates can also be shared by complementary pairs of ambipolar FETs. The exceptional features of this logic family make it a highly competitive contender to replace CMOS in the next generation of computing.

 

Applications

  • Compact high-performance computing

 

Advantages

  • Enables efficient cascaded gates
  • Requires fewer logic stages and area
  • Provides less stage delays
  • Offers 50% reduction in device count
  • Improves speed and power dissipation
  • Decreases cost of manufacture

 

IP Status

A US provisional patent application has been filed.

Patent Information: