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:
Aug. 18, 1992
Filed:
Jan. 03, 1992
Philip A Lamarre, Waltham, MA (US);
Robert L Mozzi, Lincoln, MA (US);
Raytheon Company, Lexington, MA (US);
Abstract
A method of patterning a photoresist layer to provide an aperture having retrograde sidewalls is described. Illumination may be through a conical prism arrangement or a conical reflecting mirror and cylindrical mirror arrangement. The method includes the step of directing energy towards a mask which selectively exposes portions of a photoresist layer disposed on the substrate. The energy is directed to the mask at an oblique angle with respect to the normal to the surface of the substrate. The underlying photoresist layer is obliquely sensitized by the obliquely directed illumination. The portions of the layer which are obliquely sensitized are removed leaving behind an aperture having retrograde sidewalls. The retrograde sidewalls are a preferred photoresist profile for easy and reliable lift-off of deposited material from the semiconductor substrate.