| 摘要 |
PURPOSE:To form a trapezoidal groove of a stable form by providing resist layers different in sensitivity between its upper and lower layers on a glass disk and irradiating the laser light of the same wavelength to the resist layer by changing the laser power to form a shallow groove and a deep hole. CONSTITUTION:The 1st resist layer 10 is spin coated on a glass disk 5 with lambda/8 thickness and then prebaked, and then the 2nd resist layer 11 of lambda/8 thickness is spin coated and prebaked. Thus the layer 10 is prebacked twice owing to the prebaking of the layer 11 and therefore the sensitivity of the layer 10 is deteriorated compared with the layer 11. Thus the exposure power is increased to give the exposure up to a glass surface 5 of the layer 10; while only the layer 11 is exposed when the exposure power is reduced. With development and fixing processes, a shallow trapezoidal groove 13' of lambda/8 is especially formed into a stable form. Thus the track following of a head is stabilized for an optical disk medium using such a master disk 14. |
