High-Density Recording on a Phase-Change Rewritable Disk using a 405 nm Blue Laser Diode

Shoji, M.; Nakamura, Atsushi; Miyashita, Harumitsu; Minamino, Jun-ichi; Furumiya, Shigeru; Ishida, Takashi; Ishibashi, Hiromichi

doi:10.1143/jjap.41.1687

Cited by 7 publications

(1 citation statement)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…On the other hand, the use of optical data storage media, which are not affected by external magnetic fields, is increasing very rapidly because of the convenience of using light and its large storage capacity of greater than several Gbytes. 1) The most widely used optical recording media at present are the CD (compact disk, read-only), CD-R (write-once) and DVD-R (digital versatile disk, write-Once), all of which are limited in the repeatable recording of information. Hence, much research on optical recording media on which information can be recorded and erased repeatedly is being carried out worldwide.…”

Section: Introductionmentioning

confidence: 99%

Real-Time Growth Control of Ge–Sb–Te Multilayer Film as Optical Recording Media by In Situ Ellipsometry

An¹,

Kim

2004

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

Using an in situ ellipsometer, we monitored the thin film growth curve of optical recording media in real time. Utilizing the complex refractive indices of Ge2Sb2Te5 and ZnS–SiO2 obtained from the analysis of spectroscopic ellipsometry data, we calculated the growth curves of ellipsometric constants vs thickness. By comparing the calculated growth curve of ellipsometric constants with the measured one, and by analyzing the effect of the density variation of the Ge2Sb2Te5 recording layer on ellipsometric constants, we precisely monitored the growth rate of Ge2Sb2Te5 and ZnS–SiO2 films, respectively, and eventually controlled the whole growth process of a multilayer sample made of Ge2Sb2Te5 and ZnS–SiO2 films. The accurate thickness control using in situ ellipsometry was verified through the analysis of the deposited multilayer sample using an ex situ spectroscopic ellipsometer.

show abstract

Section: Introductionmentioning

confidence: 99%

Real-Time Growth Control of Ge–Sb–Te Multilayer Film as Optical Recording Media by In Situ Ellipsometry

An¹,

Kim

2004

Jpn. J. Appl. Phys.

View full text Add to dashboard Cite

show abstract

Electrical percolation characteristics of Ge2Sb2Te5 and Sn doped Ge2Sb2Te5 thin films during the amorphous to crystalline phase transition

Kim¹,

Merget²,

Laurenzis³

et al. 2005

Journal of Applied Physics

View full text Add to dashboard Cite

Percolation effects are studied in phase change materials used for optical and electrical nonvolatile memory applications. Simultaneous measurements of the electrical resistivity and optical reflectivity allow experimental assessment of the percolation behavior associated with the mixed amorphous and crystalline phases in this class of chalcogenide materials. Dynamic analysis of the isothermal amorphous to crystalline phase transition in as-deposited amorphous Ge2Sb2Te5 and Sn doped Ge2Sb2Te5 thin films are performed. A significantly earlier onset and saturation for the change of electrical resistivity in comparison to the optically measured phase transition is observed. This behavior reflects a significant influence of percolation on the electrical properties of this class of materials, leading to a nonlinear relationship between crystallization degree and electrical resistivity. This nonlinearity is associated with the formation of highly conducting crystalline paths in a lower conducting amorphous matrix. The influence of percolation on optical properties is found to be negligible. The experimental results are quantitatively compared to Wiener bounds and Bruggeman percolation models. Substantial differences in the crystallization behavior of Ge2Sb2Te5 and Sn doped Ge2Sb2Te5 are observed: while heterogeneous nucleation induced by an interfacial layer resulting in layer-by-layer growth is observed for Ge2Sb2Te5, homogeneous nucleation and formation of prism shaped crystallites dominate in Sn doped Ge2Sb2Te5. The presented data represent the experimental analysis of percolation for the electrical resistivity in this class of materials, indicating the relevance of this effect for the adequate modeling and systematic optimization of future phase change random access memories and cognitive devices.

show abstract

Optimizing multilayer design for high density optical disks with very thin films

Wang

Gan

2002

SPIE Proceedings

View full text Add to dashboard Cite

The optical constants of each layer in the optical disk are assumed to be constant regardless of film thickness in conventional optical design and optimization of the multilayer structures. However, this assumption is not valid when the layer becomes very thin for its discontinuity. As we know, very thin layers (<50nm) are included in the highdensity and super-high density optical disks, such as DVD-RAM, high-density DVD (HD-DVD), and super-resolution near-field structure (Super-RENS). In this paper, the thickness error sensitivity factor for dielectric optical multilayer was derived from the optical matrix, and the change of optical constant of the very thin layers with the film thickness variation is analyzed at the same time. The effect of the thickness error and corresponding refractive index change on the reflectivity or reflectivity contrast of the optical disk multilayer was analyzed with a numerical calculation. As an example, we made a structure optimization for the 4-layer DVD-RAM systems with GeSbTe and AgInSbTe phasechange materials as recording media. These results are significant in improving the accuracy of optical design and thermal simulation of high density and super-high density optical disks.

show abstract

High-Density Recording on a Phase-Change Rewritable Disk using a 405 nm Blue Laser Diode

Cited by 7 publications

References 28 publications

Real-Time Growth Control of Ge–Sb–Te Multilayer Film as Optical Recording Media by In Situ Ellipsometry

Real-Time Growth Control of Ge–Sb–Te Multilayer Film as Optical Recording Media by In Situ Ellipsometry

Electrical percolation characteristics of Ge2Sb2Te5 and Sn doped Ge2Sb2Te5 thin films during the amorphous to crystalline phase transition

Optimizing multilayer design for high density optical disks with very thin films

Contact Info

Product

Resources

About