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:
Apr. 30, 1991
Filed:
Jul. 17, 1990
Ronald C Gonsiorawski, Danvers, MA (US);
Mobil Solar Energy Corporation, Billerica, MA (US);
Abstract
A method of forming a metallization pattern on a solar cell substrate having an outer layer of a selected dielectric such as silicon nitride, silicon dioxide, or glass, by removing selected portions of the dielectric layer with a laser beam. This laser exposure drives portions of the P/N junction positioned beneath the exposed regions of the substrate more deeply into the substrate. Removal of selected portions of the dielectric layer exposes regions of the silicon substrate on which conductors may be deposited by conventional immersion plating methods. This laser removal of the dielectric layer is effected in an environment substantially free of chemical etching substances. Following removal of the selected portions of the dielectric layer, the substrate is preferably immersed in a buffered oxide etch solution to remove residual silicon dioxide and is then preferably immersed in a high ratio (nitric acid to hydrofluoric acid) etch solution to remove residual silicon nitride. The method of forming a metallization pattern may be incorporated into a comprehensive solar cell fabrication process.