Readout Durability Improvement of Super-Resolution Near-Field Structure Discs with PtO_x–SiO₂ Recording and GeN_y Interfacial Layers

Abstract

We discuss the calculation of Fermi liquid parameters for the Anderson impurity model. An earlier calculation of de ChPtel is extended to a finite f-f-Coulomb interaction U and corrections of order l/Nf are studied, where Nf is the degeneracy of the localised level in the Anderson model. The lack of momentum conservation in the impurity model is found to be a complication, since the low-lying excited states are not automatically orthogonal in approximate calculations. In low-order l/Nf calculations the impurity induced quasi-particle density of states is found to have a singularity at the Fermi energy. The origin of this singularity is traced. The complications in obtaining thermodynamic properties via the calculation of Fermi liquid parameters is contrasted to the accuracy obtained in a 'direct approach', in which the calculations are performed to orders (1/Nf)', (l/Nf)' and (1/NJ2.

Atomic Layer Deposition of Platinum Oxide and Metallic Platinum Thin Films from Pt(acac)2 and Ozone

“…The super-resolution near-field structure (super-RENS), in which the diffraction limitations of a laser can be circumvented, is considered a promising technology to increase the data storage capacity of optical media. A thin PtO X layer is often chosen as a mask or an active layer in super-RENS. − On the other hand, focused ion beam or laser irradiation can be applied to high resistivity platinum oxide for metallization, patterning or writing electrical connections to the films. − Interestingly, thermal decomposition behavior of platinum oxide has been proposed to be exploited even in a thermal lithography technique . According to the authors, this approach would be useful for fabricating nanoscale structures with a high aspect ratio over large areas.…”

Readout durability improvement of super-resolution near-field structure disc using germanium nitride interface layers

“…Although fairly high laser power condition (P r = 3.0 mW) was used for the super-resolution readout, the layer kept the waveform of 97-nm and 340-nm combined marks nearly unchanged after at least 50,000 times readout and the CNR of 100-nm (monotone) marks stable to 268,000 times readout. [3,7].…”

“…Figure 8 shows the result of 100-nm (monotone) marks [3,7]. When there is no GeN y (without GeN y in the figure, P r = 2.8 mW), CNR dropped 3 dB after 75,000 times readout, but it improved by introducing GeN y (with GeN y in the figure, P r = 3.0 mW) to be 268,000 times.…”

“…In this study, we did not replace Sb-Te (Sb 75 Te 25 ) to other readout materials since it shows better super-resolution performance [6], and we intended to find another way of improving the durability that is also applicable to high P r condition (~3 mW). We demonstrate that inserting germanium nitride (GeN y ) thin films between Sb-Te and ZnS-SiO 2 layers is promising, and it can suppress some of the variation that becomes evident when repeating the readout [7]. The idea of using a GeN y interface layer partly comes from a previous study that reported an enhanced overwrite cycle durability in Ge 2 Sb 2 Te 5 rewritable media when GeN y layers were incorporated [8].…”

Study on readout durability of super-RENS disk

“…However, the readout durability must still be improved for commercialization. Recently, the readout durability was improved by use of SiO 2 -PtO x instead of PtO x , because SiO 2 -PtO x has better antistress deformation and better thermal diffusion [14]. The importance of thermal diffusion was also identified by superresolution recording with Si as an underlayer [15].…”