SUBSTRATE FOR INFORMATION RECORDING MEDIUM AND METHOD OF MANUFACTURING THE SAME

摘要

PROBLEM TO BE SOLVED: To make a magnetic disk surely and stably drivable even when a flying height is made lower than heretofore in order to deal with the trend toward a high density of data zones. SOLUTION: After a compression layer and non-compression layer are formed on a glass substrate in a polishing process step 4, the glass substrate undergoes etching treatment in an acidic solution where a hydrofluoric acid and fluoride salt are made to coexist in a texturing treatment process step 5 (first surface treatment 5a). In such a case, the acidic solution prepared to 0.3 to 0.98, more preferably 0.56 to 0.93 in the ratio X of the sum of the concentrations per mol each of the hydrofluoric acid and hydrogen ions to the sum of the concentrations per mol each of the hydrofluoric acid and fluoride ions is used as the etchant. A layer changed in properties is thereafter removed by using an alkaline solution (second surface treatment 5b) and the magnetic disk substrate is manufactured through a chemical strengthening treatment process step 6 and finishing cleaning process step 7.