Fabrication of hemispherical cavity arrays on silicon substrates using laser-assistednanoimprinting of self-assembled particles

Abstract

A new approach to fabricating hemispherical cavity arrays on silicon (Si)substrate using laser-assisted nanoimprinting of self-assembled particles ispresented. A monolayer of silica particles, with different diameters of 0.30 and0.97 µm, was deposited on a Si substrate by self-assembly. A quartz plate was tightly placed on thesample surface to firmly sandwich the self-assembled nanoparticle monolayer. The silicaparticles were imprinted into Si substrates after laser irradiation (KrF excimer laser,λ = 248 nm) on the quartz/nanoparticle/Si structure with a single pulse. Ultrasonic cleaning andhydrofluoric acid (HF) solution were used to remove the silica particles in thesample surface. Hemispherical cavities were formed on the substrate surface. Theinfluence of laser fluence and particle size on the structuring of the surface has beeninvestigated. Scanning electron microscopy (SEM) and atomic force microscopy(AFM) were performed to observe the dimensions of the cavities. One-dimensionalthermal calculation was employed to calculate the thermal effects in this process.