Recording Mechanism of High-Density Write-Once Disks Using Inorganic Recording Material

Abstract

We realized an inorganic write-once disk using a Bi-Ge nitride alloy recording layer for an optical recording system for the Blu-ray disc format. We developed a recording system, which is composed of two types of metal nitride as a recording material. One metal nitride is decomposed easily by the heat of the laser beam during recording. The other metal nitride is not decomposed at that temperature. The recording signal modulation depends mainly on the reflectivity change of the recording layer caused by the decomposition of nitride. The non-decomposing nitride controlled the reaction and prevented deformation of the layer. Thus we could obtain a well-formed minute mark. We confirmed the reliability of our hypothesis on the recording mechanism by using another material, which is composed of Sn-N and Ti-N. By this method, we confirmed that this recording mechanism can be widely applied to any inorganic recording material.

Tin Alloy Nitride Write-Once Media for Solid Immersion Lens System

“…We adopted the metal alloy nitride media that we had been researching as the write-once recording media for Blu-ray recordable discs. 2) We confirmed the feasibility of high-density recording using these media.…”

“…As a result, the recording mark was formed with the change in the optical constant and the deformation. 2) We think that the reason that we obtained a higher signal modulation using the tin alloy nitride material was that the deformation was larger than that of Bi-Ge nitride. A highrefractive-index material is required as the cover layer in the high-NA SIL system.…”

Microstructure and recording mechanism of Bi–Fe–(N) layer for high-density write-once optical disk

“…Hence, the formation of nitrogen gas bubbles caused by the decomposition of nitrides in recorded marks was expelled from the recording mechanism of Bi-Fe-͑N͒ disk samples. 14,21,22 In summary, we demonstrate the feasibility of Bi-Fe-͑N͒ layer as the recording media in HD DVD-R optical disks. PRSNR of 21.1 and sbER of 5 ϫ 10 −7 were achieved at P w = 5.7 mW in the optimized disk sample.…”

“…6 Inorganic-type materials include phase-change alloys, 7 single-layer AlSi alloys, 8 bilayer metals such as Cu/ Si, 9 Zn/ Ge, 10 Ge/ Au, 11 Cu/ a-Si, 12 etc. Among these, Bi-related alloys such as Bi-Ge alloy 13,14 and Bi oxide ͑BiFeO͒ 15,16 exhibit promising applications for write-once data storage. For Bi-Ge-͑N͒ alloy, the recording mechanism was attributed to the reflectivity change caused by the decomposition of Bi nitride in the recording layer as well as the deformation in recording marks due to the gas release.…”

“…For Bi-Ge-͑N͒ alloy, the recording mechanism was attributed to the reflectivity change caused by the decomposition of Bi nitride in the recording layer as well as the deformation in recording marks due to the gas release. 14 As to the BiFeO, the signal recording was resulted from the crystallization of Bi and BiO. 16 This work studies the feasibility of Bi-Fe-͑N͒ recording layer to HD DVD recordable ͑DVD-R͒ optical disks and the recording mechanism.…”