Placement of Carbon Nanotube Guided by DSA Patterning

A method of forming a carbon nanotube-based field effect transistor (FET) device, the method comprising the steps of:

• providing a semiconductor substrate;
• disposing a dielectric on the semiconductor substrate;
• forming a placement guide layer on the dielectric;
• using DSA of a block copolymer to create a pattern in the placement guide layer, wherein the pattern comprises multiple trenches in the placement guide layer, wherein there is a first charge on sidewall and top surfaces of the trenches and a second charge on bottom surfaces of the trenches, and wherein the first charge is different from the second charge;
• depositing a solution containing carbon nanotubes onto the substrate, wherein the carbon nanotubes are functionalized to have the first charge on surfaces thereof, and wherein self-assembly of the deposited carbon nanotubes within the trenches occurs based on i) attractive forces between the first charge on the surfaces of the carbon nanotubes and the second charge on the bottom surfaces of the trenches and ii) repulsive forces between the first charge on the surfaces of the carbon nanotubes and the first charge on sidewall and top surfaces of the trenches;
• removing the placement guide layer;
• and
• forming metal source and drain contacts to the carbon nanotubes.