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. 02, 1996
Filed:
Jul. 29, 1994
Thomas G Bifano, Mansfield, MA (US);
The Trustees of Boston University, Boston, MA (US);
Abstract
A process for manufacturing an optical data storage disk stamper includes the steps of providing a chemically vapor-deposited, silicon carbide substrate having a toughness of about 4.5 MPa.sqroot. m, a roughness of about 1 nm, and a flatness of about 6 .mu.m and depositing a negative photoresist on a surface of the substrate. The substrate has a diameter greater than about 120 mm and a thickness greater than about one mm. The negative photoresist then is exposed with a laser to form a negative, data pattern in the photoresist. The photoresist is developed, and the ceramic substrate is ion machined to form the data pattern, in the substrate, such that a spiral track of ridges and lands is formed wherein each ridge has a height of about in a range of 20 to 200 nm. After the data pattern has been ion machined into the substrate, the developed photoresist is stripped from the substrate.