Information recording medium and information memory apparatus

An information storage medium comprising:

• a substrate;
• a thin film formed on the substrate in a range of 10 to 40 nm thick and having a reflectance changed by a phase change caused by irradiation of an energy beam irradiated via the substrate;
• a first reflective layer on the thin film directly or via an intermediate layer;
• a second reflective layer disposed between the substrate and the thin film in a range of 10 to 50 nm thick;
• and
• wherein the thin film includes at least Ge, Te and Sb, and the second reflective layer consists of Si, or comprises 75 to 99 atomic % Si and 1 to 25 atomic % element of at least one of Ge, Au, Ag, Cu, Al, Ni, Fe, Co, Cr, Ti, Pd, Pt, W, Ta, Mo, Sb, Bi, Dy, Cd, Mn, Mg, V, Zn, Ga, Tl, Pb, C, B, S, N, Sn and In.

An information storage medium comprising:

• a substrate;
• a thin film formed on the substrate and having a reflectance changed by a phase change caused by irradiation of an energy beam irradiated via the substrate;
• a first reflective layer and a second reflective layer on the thin film directly or via an intermediate layer;
• said thin film including at least Ge, Te and Sb;
• said first reflective layer and said second reflective layer being piled up in recited order from a thin film side, the first reflective layer comprising a material having an attenuation factor k of 2 or less and selected from the group consisting of Si, Si--Ge, Si--Au, Si--Ag, Si--Cu, Si--Al, Si--Ni, Si--Fe, Si--Co, Si--Cr, Si--Ti, Si--Pd, Si--Pt, Si--W, Si--Ta, Si--Mo, Si--Sb, Si--Bi, Si--Dy, Si--Cd, Si--Mn, Si--Mg, Si--V, Si--Ga, Si--Ti, Si--Pb, Si--C, Si--B, Si--N, Si--Sn, Si--In or a mixture of Si--N and Si--In, and the second reflective layer comprising a material having an attenuation factor k of at least 3.