Preparation of two-dimensional thin films by backside irradiation pulsed laser deposition method using powder target

In this work, two-dimensional thin films were prepared by pulsed laser deposition (PLD) via backside irradiation. For this, a handmade transparent target holder made of quartz-glass was used to hold the powder targets. Visible-wavelength pulsed laser irradiation was applied from the holder side to the substrate. Using this new method, indium (In) and zinc (Zn)-concentrated thin films were prepared on a silicon substrate. The deposition rate of the film prepared with this method was calculated from the thickest position of the prepared film and the deposition time. The deposition rate was lower than for films prepared via conventional PLD. Two-dimensional profiles of the prepared films via backside irradiation PLD displayed a convex shape and its spatial resolution strongly depended on the laser profile. X-ray photoelectron spectroscopy measurements suggested that tailored In and Zn composition thin films could be prepared with this method using an In₂O₃ and ZnO powder target.