A nonvolatile nanoelectromechanical memory element utilizing a fabric of carbon nanotubes

Manufacturability of electronic devices based on carbon nanotubes (CNT) generally depends on the ability to manipulate and control individual structures at the molecular level. A novel technique has been developed to overcome this hurdle, allowing CNT-based nano-electromechanical devices to be fabricated directly on existing production CMOS fabrication lines. The first demonstration of this technique has resulted in a CNT nonvolatile memory element. This unique approach relies on the deposition and lithographic patterning of a 1-2 nm thick fabric of nanotubes which retain their molecular-scale electromechanical characteristics, even when patterned with 180 nm feature sizes. Individual patches of this CNT fabric can be elastically deformed by electro-static attraction to metal electrodes, creating a pair of stable nonvolatile states around the equilibrium of two molecular-level forces: an attractive van der Waals force and the restoring tensile strain within the deformed fabric. A CMOS-compatible fabrication process for these devices has been developed and demonstrated which is free from metallic or material contaminants and particulates. Because these nonvolatile memory elements are created in an all thin-film process, they can be monolithically integrated directly within existing CMOS circuitry to facilitate addressing and readout. Design considerations and preliminary device switching characteristics are presented.