JPS647351A - Magneto-optical disk substrate - Google Patents

Abstract

PURPOSE:To exactly execute recording and erasing of information at a high speed by providing a light transmittable poor thermal conductor layer having a thickness of a prescribed range under the recessed part of a film body provided on the surface of a light shieldable substrate. CONSTITUTION:The film body 2 provided with ruggedness is provided on the surface of the light shieldable substrate 1. The light transmittable poor thermal conductor layer having 100nm-5mum thickness is formed under the recesses of the film body 2. This film thickness is uniform over the entire region of the substrate 1; thereafter, a coated film having ruggedness is formed by using a coated film of an org. metal compd. and a mold material having fine ruggedness, then the film is baked and solidified. Part of the poor thermal conductor layer is thereafter selectively removed by using an etching method such as photolithographic method, etc. The effect of insulating the quantity of heat by laser light is not generated if the poor thermal conductor layer is thinner than 100nm. The heat insulation effect is nearly fixed and is not increased and the exfoliation of the substrate and the film is caused on the contrary, if sad layer is thicker than 5mum.