FPCNA: A carbon nanotube-based programmable architecture

In the hunt to find a replacement for CMOS, material scientists are developing a wide range of nanomaterials and nanomaterial-based devices that offer significant performance improvements. One example is the carbon nanotube field-effect transistor (CNFET), which replaces the traditional silicon channel with an array of semiconducting carbon nanotubes (CNTs). Due to the increased variation and defects in nanometer-scale fabrication and the regular nature of bottom-up self-assembly, field-programmable devices are a promising initial application for such technologies. In this chapter, we detail the design and evaluation of a nanomaterial-based architecture called FPCNA (field-programmable carbon nanotube array). Nanomaterial-based devices and circuit building blocks are developed and characterized, including a lookup table created entirely from continuous CNT ribbons. To determine the performance of these building blocks, variation-aware physical design tools are used, with statistical static timing analysis (SSTA) that can handle both Gaussian and non-Gaussian random variables. When the FPCNA architecture is evaluated using this computer-aided design (CAD) flow, a 2.75× performance improvement is seen over an equivalent CMOS FPGA at a 95% yield. In addition, FPCNA offers a 5.07× footprint reduction compared with a baseline FPGA.