Effects of Solvent and Ambient Humidity on Nanodot Structures for Near-Field Optical Data Storage Using Self-Assembled Diblock Copolymer

Abstract

We present the formation of nanodot structures on a glass substrate by the self-assembly of a diblock copolymer. The structures can be used as nanopatterned media for near-field optical data storage with high data density. Improvements in the carrier-to-noise ratio (CNR) and in the uniformity of the recorded bit marks are expected with these structures. It is found that the structure of nanodots depends strongly on the ambient humidity during dripping and subsequent spin-casting and also on the solvent used. Nanodots of uniform size can be formed on a glass substrate with benzene, toluene, or toluene blended with acetone as a solvent when the ambient humidity is in the range of 60% to 70%. The size of the individual nanodots as well as the distance between two consecutive nanodots can be controlled, and the nanodots may be aligned like regular hexagonal close-packed structures by adjusting the volume ratio of acetone to toluene.

Influence of Temperature and Type of Solvents on the Microdomain Orientation ofPS‐b‐P2VPUltrathin Films by Solvent Annealing

“…Benzene, chloroform, 1,4‐dioxane, and tetrahydrofuran (THF) are good solvents for both PS and P2VP blocks. Toluene and methylethylketone (MEK) are selective solvents for PS block while acetone and ethanol are selective solvents for P2VP block . In this experiment, THF, acetone and toluene were selected from each category for solvent‐annealing process.…”

Fabrication of Nanohole Array via Nanodot Array Using Simple Self-Assembly Process of Diblock Copolymer

“…The details of the fabrication procedure of the nanodot array were described in our previous papers. 5,6) To fabricate the nanohole array, we convert the nanodot arrays to nanohole arrays by dripping pure ethanol onto the nanodot array obtained, as shown in Fig. 1(b).…”

“…Considerable research has been conducted on copolymers that can be used to produce a honeycomb structure, 1) phaseseparated structures, 2) nanoparticles, 3) and nanodots. 4) In our previous papers, 5,6) we demonstrated the fabrication of nanodot arrays on a glass substrate using self-assembling polystyrene-block-poly(2-vinylpyridine) (PS-P2VP). Micelles of PS-P2VP were formed in a solvent and became self-aligned.…”

Control of Alignment Regularity and Density of Nanodots by Changing Concentration and Molecular Weight of Self-Assembling Diblock Copolymer

“…We present the application of a self-assembling process to nanopatterned media, [11][12][13] consisting of well-aligned nanodots with a recordable material doped in it for near-field optical data storage. In our previous publication, 14) we reported that nanodots of uniform size could be formed on a glass substrate with a self-assembled diblock copolymer in benzene, toluene and toluene blended with acetone solvents. In this paper, we show that the alignment regularity and density of a nanodot array can be controlled by changing the molecular weight as well as the concentration of the diblock copolymer in solution.…”

“…The details of the fabrication procedure for the nanodots were described in our previous paper. 14) We fabricated the nanodots on a glass substrate by the self-assembly of PS-P2VP in benzene, toluene and toluene blended with acetone solvents. Benzene is a good solvent for both blocks, while toluene is a selective solvent for the PS block only and acetone for the P2VP block only.…”