Back to results
US 12,002,674 B2Granted
Macromolecular sieves from semiconductor membranes for shape-based separation and sensing
AssigneeWiSys Technology Foundation, Inc.
InventorsGokul Gopalakrishnan, Mark Elliot Levenstein
Life of this patent
Estimating the term…
Abstract
Methods for making molecular sieves are provided. The molecular sieves are comprised of thin semiconductors films in which a plurality of apertures is defined. The apertures are non-circular, nanoscale openings with tapered sidewalls that selectively pass certain molecules, while discriminating against the passage of other molecules.
Claims19
A method of fabricating a molecular sieve, the method comprising:
- depositing a layer of masking material comprising silicon nitride, chromium, chromium oxide, or a chromium-gold multilayer onto a single-crystalline semiconductor membrane;
- depositing an electron beam sensitive polymer over the layer of masking material;
- patterning an array of holes into the electron beam sensitive polymer via electron beam lithography;
- transferring the pattern of holes into the layer of masking material using a plasma or wet chemical etch to form a mask;
- and
- etching a pattern of apertures into the single-crystalline semiconductor membrane using the mask and an anisotropic chemical etch, wherein the apertures extend through the single-crystalline semiconductor membrane from an upper opening to a lower opening and have a tapered depth profile, and further wherein the lower openings have at least one lateral dimension that is smaller than 5 μm.
3 more elements
Dependencies are inferred from the claim text.