Brian Dean Scott

US Patent:

6542282, Apr 1, 2003

Filed:

Dec 31, 2001

Appl. No.:

10/036697

Inventors:

David M. Smith - Plano TX
Eric R. Trumbauer - Frisco TX
Ronald C. Roth - McKinney TX
Brian P. Scott - Sachse TX

Assignee:

Texas Instruments Incorporated - Dallas TX

International Classification:

G02B 2600

US Classification:

359291, 438707, 430 11

Abstract:

A method of patterning a metal layer that cleans the residue from a metal etch process without removing a photoresist etch mask. The method is particularly useful for the fabrication of micromirror devices, or other MEMS devices that use photoresist spacer layers. A photoresist layer is spun on to the mirror metal layer in step The photoresist is patterned and developed in step to form openings to the metal layer. The openings define areas where the mirror metal layer will be removed. The patterned photoresist is inspected in step The mirror metal layer is etched in step using the patterned photoresist layer as an etch mask. After the mirror metal has been etched, the webbing and other residues are removed in a clean up process that uses photoresist developer as a solvent to remove the webbing. After the developer clean up process, the mirrors are inspected in step to verify the proper gaps have been etched between the mirrors and the removal of the mirror etch residue. A photoresist saw prep coating is then spun onto the wafer in step the wafers are sawn in step and scrubbed in step before the mirrors are undercut in step The undercut process removes the photoresist spacer layers on which the hinge yoke and mirror have been fabricated, allowing mirrors to rotate about the torsion hinges.