| 摘要 |
PCT No. PCT/JP98/02453 Sec. 371 Date Apr. 1, 1999 Sec. 102(e) Date Apr. 1, 1999 PCT Filed Jun. 3, 1998 PCT Pub. No. WO98/55994 PCT Pub. Date Dec. 10, 1998In an optical recording information recording medium of a structure having protection layers on both surfaces of a recording layer, overwrite cyclability is improved without deteriorating the reliability of recorded data. To achieve this, the first protection layer is deposited by a sputtering method from a target made of a mixture comprising ZnS and SiO2 without adding an O2 gas and a H2 gas to a sputtering atmosphere, the second protection layer is deposited by a sputtering method using a target made of a mixture comprising ZnS and SiO2 by adding an O2 gas and an H2 gas to the sputtering atmosphere. Especially, an optical information recording medium having a high reliability of recorded data and capable of overwriting of 300,000 cycles or more can be obtained, particularly, by controlling the partial pressure of the added O2 gas to 10x10-6-50x10-6 Torr and the partial pressure of the added H2 gas to 20x10-6-50x10-6 Torr upon deposition of the second protection layer. |
