Super-resolution by elliptical bubble formation with PtOx and AgInSbTe layers

Abstract

The recording and retrieval of signals below 100 nm mark length were attempted with elliptical bubble-type super-resolution technology with platinum oxide (PtOx) and ductile AgInSbTe layers, using the same optical system as that of a digital versatile disk (a 635 nm wavelength red laser system). The carrier-to-noise ratio (CNR) of over 47 dB for 100 nm mark length signals (over 43 dB for 80 nm mark length signals) was obtained, which can be considered as a commercially acceptable level of CNR. The recording mechanism of the sample disk was shown through the transmission electron microscopy cross-section image observation to be by rigid elliptical bubble formation at the PtOx layer located between the AgInSbTe layers. The results of this report represent the potential for a much higher-density storage using the red laser system and a subterabyte optical storage using the blue laser system.

Temperature dependence of thermal properties of Ag8In14Sb55Te23 phase-change memory materials

“…With the development of the phase-change memory, various materials were examined, and the materials of the best performances in terms of speed and stability were found to be GeSbTe (abbreviated as GST) family, such as Ge 2 Sb 2 Te 5 and Ge 1 Sb 4 Te 7 [4,9,16,17,[21][22][23], and AgInSbTe (abbreviated as AIST) family, such as Ag 3.4 [2,3,7,[11][12][13][14][15][24][25][26][27][28]. The thermal properties of GST family were measured and studied in details, and the studies showed that there were common characteristics for different members in the GST family due to the distorted NaCl-type rock structures [21,22].…”

“…When the laser beam is switched off, the melted marks quench into an amorphous state due to the high thermal conductivity of the substrate underneath the phase-change materials. Conversely, the recorded marks are erased when the materials are heated above the glass transition temperature but yet below the melting threshold so that the materials return to the crystalline state [7][8][9][10][11][12][13][14][15][16][17]. For the nonvolatile electrical storage, applying a higher voltage pulse (reset pulse) to the crystalline state with low resistivity leads to the local melting and consequently the formation of an amorphous information bit with high resistivity due to the rapid quenching.…”

“…Chalcongenide phase-change materials are extensively used as the optical and nonvolatile electrical data storage media due to the apparent difference in optical reflectivity and electrical resistivity between the crystalline and amorphous state [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. For optical data storage, the recording is achieved by forming amorphous marks on a crystalline base with a focused laser beam.…”

Applications of Nonlinear Super-Resolution Thin Films in Nano-optical Data Storage

“…The results showed that the 100 nm recording marks in the track direction were realized, and the mark size corresponds to 1/10 of the laser spot size (∼1.0 um). Figure 8.19 presents the experimental results from [20], and Fig. 8.19a is the dependence of CNR on mark size.…”

“…In the bubble-type marks, the Pt particles can enhance the readout signal and improve the CNR of dynamic readout. In order to demonstrate the schematics, Kim et al carried out the dynamic recording and readout by using Pulstec DDU-1000 with a laser wavelength of 635 nm and a lens with an NA of 0.60 [20]. The disks were rotated at a velocity of 6.0 m/s.…”