Patent ID: 11891689
Assignee: ARIZONA BOARD OF REGENTS ON BEHALF OF ARIZONA STATE UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC C  B  G | IPC B  C  G

Claim 3:
4. A method of fabricating a nanopore sensor, the method comprising:
depositing a first oxide layer on a first side of a sapphire substrate and a second oxide layer on a second side of the sapphire substrate opposite the first side;
patterning the second oxide layer to form an etch mask having a mask opening in the second oxide layer;
performing a crystalline orientation dependent wet anisotropic etch on the second side of the sapphire substrate using the etch mask to form a cavity having sloped side walls through the sapphire substrate to yield an exposed portion of the first oxide layer, each of the sloped side walls being a crystalline facet aligned with a respective crystalline plane of the sapphire substrate;
depositing a silicon nitride layer on the first oxide layer;
removing the exposed portion of the first oxide layer in the cavity, thereby defining a silicon nitride membrane in the cavity; and
forming an opening through the silicon nitride membrane, wherein the opening is a nanopore with a diameter in a range of 1 nm to 20 nm,
wherein the mask opening is in the shape of a hexagon, and
wherein an edge of the hexagon is aligned at an offset angle α from a crystalline plane of the sapphire substrate, where 5°<α<55°.