The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 03, 2001
Filed:
Feb. 16, 1999
Douglas S. Hobbs, Lexington, MA (US);
Optical Switch Corporation, Richardson, TX (US);
Abstract
A double exposure process is disclosed whereby a first exposure produced by conventional photolithographic techniques generates a latent negative image in a photoresist etch mask layer (,), the image subsequently employed to modulate a second exposure generated by the multiple beam interferometric lithography technique. Periodic surface relief structures (,) patterned by the second exposure and formed after development of the exposed photoresist material, are restricted to regions (,) defined by the initial exposure, with the photoresist material (,) outside these regions remaining unmodulated, or devoid of the periodic structures (,), and suitable for use as a mask in a subsequent etching process.