Atomically Stepped Glass Surface Formed by Nanoimprint

Abstract

We investigated atomic-scale surface modifications of silicate glass by nanoimprint using an atomically stepped sapphire (α-Al2O3 single crystal) plate as nanopattern mold. The sapphire mold had regularly arranged straight atomic steps, with uniform height and terrace width of about 0.2 and 80 nm, respectively. During pressing, vertical positions of the sapphire mold and glass plate significantly affected the morphology of the imprinted glass surface. The nanopattern was transferred to the glass surface when the mold was set on the glass plate, while the nanowave pattern was formed on the glass surface when the glass plate was set on the mold.

Sub-nanoscale nanoimprint fabrication of atomically stepped glassy substrates of silicate glass and acryl polymer

“…So far, novel feature sizes as small as 2 nm have been obtained on the surface of a poly(acrylic acid) (PAA) polymer by imprinting with a single-walled carbon nanotube mold [12]. Recently, we successfully performed sub-nanometer-scale surface patterning on sodalime silicate glasses as well as acryl polymers by the thermal nanoimprint technique [13][14][15][16][17][18], in which self-organized nanopattern molds of atomically stepped sapphire (a-Al 2 O 3 single crystal) substrates were applied as the imprint template [19]. These nanostructured sapphire molds exhibit the unique surface morphology having about 0.2-nm-high straight steps and about 100-nm-wide ultrasmooth terraces [19,20].…”

“…The atomic-step height on the sapphire wafers was found to depend on the crystallographic plane of the outermost surface. For the (0001) c-plane, (11)(12)(13)(14)(15)(16)(17)(18)(19)(20) a-plane, and (10-12) r-plane sapphire substrates, each atomic step was reported to be 0.21, 0.24, and 0.34 nm, respectively [20].…”

Atomic step patterning in nanoimprint lithography: Molecular dynamics study

“…[12][13][14] The composition of the commercial glass used in the experiment is 73. stepped sapphire molds were obtained by annealing mirrorpolished commercial sapphire (0001) substrates with a nominal offcut angle of 0.15 at 1000 C for 3 h in air. The mold has a step height of 0.21 (60.02) nm and a terrace width of approximately 80 nm.…”

“…11 With regard to the vertical resolution, Akita et al produced 0.2-0.3-nm stepped glass surfaces. [12][13][14] However, experimental evaluation of the ultimate resolution in NIL is difficult because of the observation limit of the measurement system.…”

Nanostripe patterning of glass surface by nanoimprint using self-organized oxide mold

“…This selforganized nanopattern of the stepped sapphire is also applicable to the nanoimprint mold for oxide glasses, partly because of its high thermal stability, and durability against oxidation and mechanical stress. Recently, we applied glass nanoimprint using the stepped sapphire mold for oxide glass [16]. In this study, we examine the nanoimprint conditions for oxide glasses in detail.…”