Carbon Nanotube Based Memory Development and Testing

Manufacturability of most electronic devices based on carbon nanotubes depends on the ability to place, manipulate, and control individual structures at the molecular level. This approach is problematic due to the precise placement and registration required thus making large scale manufacturing difficult if not impossible. A novel technique has been developed to overcome this hurdle, allowing CNT based nano-devices to be fabricated directly on existing production CMOS fabrication lines. This technique has been demonstrated in a Class 1 commercial fab and enables the fabrication of CNT nonvolatile memory devices directly onto CMOS substrates. This unique approach relies on the deposition and lithographic patterning, using standard semiconductor toolsets, of a 1-2 nm thick fabric of carbon nanotubes which retain their molecular scale, electro-mechanical characteristics, even when patterned to less than 100 nm feature sizes. The non-volatile CNT switch is turned on using electrostatic forces and remains in the ON state through van der Waals (VDW) attraction. The switch is turned off by overcoming the VDW forces and creating separation of the tubes from a contact.