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:
Mar. 02, 1976
Filed:
Jul. 01, 1974
Ronald E Sheets, Westminster, CA (US);
Tamarack Scientific Co., Inc., Orange, CA (US);
Abstract
A system is disclosed for exposing to ultraviolet light a semi-conductor or hybrid substrate coated with photo-resist, in back of a mask having bars and very narrow slits, the diffraction patterns ordinarily experienced at the substrate being virtually eliminated through use, between the light source and the mask, of a light integrator comprised of two successive matrixes of very small lenses or lenticules. The lenticules form a large number of magnified, superimposed, slightly displaced images of the light source in the plane of the substrate; and when the slitted mask is interposed, this light forms a large number of diffraction patterns on the substrate which, because of their large number, superimposition, and slight displacement, results in extreme uniformity of light intensity and sharp resolution throughout the pattern of light on the substrate. A variable aperture is used in connection with the light integrator, and controls the half-angle of collimation by a collimator lens placed between the light integrator and the mask. Means are also provided for modifying the aperture pattern of this aperture plate changing it, for example, to one or more off-axis sub-apertures. a field lens is also used to improve superimposition of the lenticule images on the target.