Thermal Recording for High-Density Optical Disc Mastering

Self Cite

We optimized the silicon master structure with the dielectric material as the recording material of the thermal recording. We confirmed that a 48-nm-long pit was able to be recorded with a laser of 405 nm wavelength. As a result of that, we could make a 250 gigabyte (GB) data capacity master with a conventional laser beam recorder (LBR). 75 and 100 GB discs with a photopolymer cover film made by the same method were able to be read with a solid immersion lens (SIL)-equipped tester. The 75 and 100 GB disc jitter values were 6 and 10%, respectively. We also confirmed that a 37-nm-long pit could be formed with the SIL-equipped tester as the recording machine of the thermal recording.

Section: Playback Resultsmentioning

confidence: 99%

Section: Process Flowmentioning

confidence: 99%

Improvement of Thermal Interference for High-Density Thermal Recording Mastering

Murakami¹,

Yamaoka²,

Matsukawa³

et al. 2011

Self Cite

“…The candidates for future optical data storage systems are optical memories that utilize two-photon absorption, 5) solid immersion lenses (SILs), 6) super-resolution, 7) and holography. [8][9][10][11] An optical memory system that utilizes holography is called a holographic data storage system (HDSS).…”

Section: Introductionmentioning

confidence: 99%

Interpixel crosstalk cancellation on holographic memory

Ishii

Fujimura

2017

In holographic memory systems, there have been no practical techniques to minimize interpixel crosstalk thus far. We developed an interpixel crosstalk cancellation technique using a checkerboard phase pattern with a phase difference of π/2, which can decrease the size of the spatial filter along the Fourier plane with the signal-to-noise ratio (SNR) kept high. This interpixel crosstalk cancellation technique is simple because it requires only one phase plate in the signal beam path. We verified the effect of such a cancellation technique by simulation. The improvement of SNR is maximized to 6.5 dB when the filter size specified in the Nyquist areal ratio is approximately 1.05 in ideal optical systems with no other fixed noise. The proposed technique can improve SNR by 0.85 in an assumed monocular architecture at an actual noise intensity. This improvement of SNR is very useful for realizing high-density recording or enhancing system robustness.

“…Heat-mode or thermal lithography with laserinduced heating has been developed as a mastering technique for high-density recording media. [3][4][5][6][7][8][9][10][11][12][13][14] This process does not necessarily require the use of a vacuum system, so it is a low-cost and energy-efficient technology. The temperature distribution in the area irradiated follows a Gaussian distribution, and the etching resistance increases only in the vicinity of the maximum temperature.…”

mentioning

confidence: 99%

“…16,17) These mixtures can also be used as selectively etchable materials in thermal lithography, where they provide convex patterns with smooth edges. 10,[12][13][14] The pattern morphologies depend on the structure of the sample. In previous studies, however, thin films with a thickness of less than 50 nm were typically used to reduce the pit mark size for high-density recording media, and the pattern morphologies were not investigated in detail.…”

mentioning

confidence: 99%

Unique ZnS–SiO₂Morphologies Reflecting a Laser-Induced Heat Distribution

Mori

Itoh

2013

Unique morphologies including a hemispherical dot and an inverse trapezoid line were fabricated from a mixture of zinc sulfide (ZnS) and silicon dioxide (SiO2) using thermal lithography. Depending on the laser power, three types of morphologies were formed for each of the dot and line patterns. The patterns were affected by the concentric heat transfer from the underlying light-absorption layer, and the transverse heat transfer caused by the spatial restriction. These unique morphologies are difficult to fabricate using photolithography, and they are therefore promising for new functional applications involving microscale structures.