Method for fabricating a glass substrate for an information recording medium, and magnetic disk using the same
A method for fabricating a glass substrate containing SiO 2 as a main ingredient thereof for an information recording medium which ensures removal of abrasive or foreign mater adhered to the glass substrate without complicating a cleaning step, involves, after a polishing step, keeping the surface of the glass substrate in contact with a liquid having a Si element elution in a range from 100 to 10 000 ppb/mm 2 before a scrub-cleaning step.
1. A method for fabricating a glass substrate for an information recording medium containing SiO 2 as a main ingredient thereof, the method comprising the steps of:
polishing the glass substrate;
halting polishing of the glass substrate;
maintaining a surface of the glass substrate in contact with a liquid for a duration ranging from 60 minutes to 300 minutes, immediately after the polishing is halted, to permit foreign matter adhered to the surface of the substrate to float away from the surface of the substrate;
the liquid having an Si element elution in a range from 200 to 3,000 ppb/mm 2 , wherein said Si element elution range is selected to provide a slight erosion of the glass substrate without degrading a surface smoothness of the glass substrate; and
cleaning by scrubbing the glass substrate subsequent to the step of maintaining.
2. The method according to claim 1 , wherein the step of maintaining the surface of the glass substrate in contact with the liquid is performed inside scrub-cleaning equipment.
3. The method according to claim 2 , wherein, in the step of maintaining the surface of the glass substrate in contact with the liquid, the liquid is supplied by use of a mechanism for supplying a scrub-cleaning liquid.
4. The method according to claim 1 , wherein the surface of the glass substrate is maintained in contact with the liquid with the glass substrate immersed in the liquid which is collected.