Search

The well-controlled fabrication of microtrenches including inclined features using normal incidence with gradual shifting of the irradiated area was demonstrated. Based on the variation of trench width depending on the laser fluence, the existence of gaps between the edge of the irradiated area and sidewall of the trench was shown. Because of these gaps, the shifted laser pulse can stay at the bottom of the trenches in the fabrication of the inclined features. In laser-induced backside wet etching (LIBWE), the photo-activated region generated within organic solution would act on the glass surface and results in etching. It was indicated that the photo-activated region generated at the bottom of the trenches acted not only on the bottom of the trench but also on the sidewalls. Based on such etching of the sidewall, fabrication of inclined features becomes possible. In this method, the tilting angle can be changed within one deep trench. Flexible structure formation deep inside the silica glass can be achieved. [ABSTRACT FROM AUTHOR]

Abstract: Fabrication of FeSi2 nano- and microdot array was performed by utilizing droplet ejection through laser-induced forward transfer, which we named laser-induced dot transfer (LIDT). An amorphous FeSi2 alloy source film on a transparent support was illuminated from the support by a nanosecond excimer laser pulse patterned into migcrogrid form, resulting in size- and site-controlled dot deposition. Micro-Raman spectroscopy confirmed β-FeSi2 semiconducting crystalline phase even on unheated substrates. Moreover, the microdots exhibited near-infrared photoluminescence at the peak wavelength of 1.57μm, which comes from the β-FeSi2 crystalline phase precipitated during the LIDT process. The dot size was successfully reduced to approximately 500 and 300nm in diameter and height, respectively. This technique is useful for integrating functional nano- and microdots under atmospheric room-temperature conditions. [Copyright &y& Elsevier]

Abstract: Deep microtrenches having a high aspect ratio on the surfaces of silica glass were fabricated by laser-induced backside wet etching (LIBWE). The focused laser beam of a diode-pumped solid state (DPSS) UV laser at λ =266nm on the repetition rate of 30–40kHz was directed to the sample cell of the glass by a galvanometer-based point scanning system. Vertical and inclined trench structures were successfully fabricated on the glass by changing the incident angle of the laser beam. The depth of filed (DOF) in LIBWE was analyzed by inclined laser irradiation. Flexible rapid prototyping by the mask-less exposure system was demonstrated. [Copyright &y& Elsevier]

Abstract: We have constructed a system for surface-microstructuring transparent materials, such as silica glass, using laser-induced backside wet etching (LIBWE), which includes an excimer laser and a mask projection system. In this report, we describe the advantages of the LIBWE method and present various results showing deep microtrenches fabricated using this method. We examine the applicability of this method to rapid prototyping, and propose a mechanism for the formation of deep microtrenches. [Copyright &y& Elsevier]

Microstructures with well-defined 1 μm-scale grating and grid patterns were fabricated on the surfaces of silica glass using a laser-induced backside wet etching (LIBWE) method by nanosecond-pulsed KrF excimer laser irradiation through a mask projection system. In the former case, gratings as narrow as 0.75 μm-sized were successfully etched on the glass surface via fine adjustments to the projection system. To investigate the etching mechanisms, formation and propagation of the shockwave and micro-bubbles after laser irradiation, at the interface of the silica glass and the toluene solution, were monitored using time-resolved shadowgraph microscopy, from the front- and side-view directions. [Copyright &y& Elsevier]