Nanotube- and nanocrystal-based non-volatile memory
View Patent ↗An embodiment is a transistor for non-volatile memory that combines nanocrystal and nanotube paradigm shifts. In particular an embodiment is a transistor-based non-volatile memory element that utilizes a carbon nanotube channel region and nanocrystal charge storage regions. Such a combination enables a combination of low power, low read and write voltages, high charge retention, and high bit density. An embodiment further exhibits a large memory window and a single-electron drain current.
1. A transistor comprising:
a nanotube channel formed on an oxide;
a first dielectric formed on the nanotube channel; and
a plurality of metal nanocrystals formed on the first dielectric adjacent to the nanotube channel, wherein the plurality of metal nanocrystals form an array of discrete floating gates.
2. The transistor of claim 1 further comprising:
a second dielectric formed on the first dielectric and on the metal nanocrystals.
3. The transistor of claim 2 further comprising:
a first electrode coupled to a first end of the nanotube channel; and
a second electrode coupled to a second end of the nanotube channel.
4. The transistor of claim 3 further comprising:
a gate electrode formed on the second dielectric substantially between the first electrode an the second electrode.
5. A method comprising:
forming a nanotube channel on an oxide;
forming a first dielectric on the nanotube channel; and
forming a plurality of metal nanocrystals on the first dielectric adjacent to the nanotube channel, wherein the plurality of metal nanocrystals form an array of discrete floating gates.
6. The method claim 5 further comprising:
forming a second dielectric on the first dielectric and on the metal nanocrystals.
7. The method of claim 6 further comprising:
forming a first electrode coupled to a first end of the nanotube channel; and
forming a second electrode coupled to a second end of the nanotube channel.
8. The method of claim 7 further comprising:
forming a gate electrode on the second dielectric substantially between the first electrode an the second electrode.