Abstract: A process for manufacturing an optical data storage disk stamper includes the steps of providing an amorphous electroless nickel substrate including phosphorous in the amount in a range of about 5 to 15 percent by weight having a toughness of about 100 MPa.sqroot. m, a roughness in a range of about 1 to 50 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 300 .mu.m. 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 less than about 150 nm. After the data pattern has been ion machined into the substrate, the developed photoresist is stripped from the substrate.