Method for controlling energy density for reliable pulsed laser deposition of thin films

Abstract

We have established a methodology to stabilize the laser energy density on a target surface in pulsed laser deposition of thin films. To control the focused laser spot on a target, we have imaged a defined aperture in the beamline (so called image-focus) instead of focusing the beam on a target based on a simple "lens-focus." To control the laser energy density on a target, we have introduced a continuously variable attenuator between the output of the laser and the imaged aperture to manipulate the energy to a desired level by running the laser in a "constant voltage" mode to eliminate changes in the lasers' beam dimensions. This methodology leads to much better controllability/reproducibility for reliable pulsed laser deposition of high performance electronic thin films.

Role of scaffold network in controlling strain and functionalities of nanocomposite films

“…An image beam method was used to obtain stabilized and uniform laser energy density on the target ( 50 ). The composite targets were synthesized by the conventional ceramic sintering process.…”

“…The vertically aligned LSMO:MgO nanocomposite films (250 to 600 nm) were heteroepitaxially grown on STO (001) substrates by pulsed laser deposition (Lambda Physik, 248 nm, 2 J/cm 2 ). An image beam method was used to obtain stabilized and uniform laser energy density on the target (50). The composite targets were synthesized by the conventional ceramic sintering process.…”

Oxygen Vacancy-Tuned Physical Properties in Perovskite Thin Films with Multiple B-site Valance States

“…SFO thin films were grown by PLD using a KrF excimer laser (Lambda Physik LPX 300, λ = 248 nm, 2 Hz). The laser beam, defined by the image beam method 44 , was focused onto the target with an energy density of 1.87 J/cm 2 . Prior to the deposition, the chamber was pumped down to a base pressure of 1 × 10 −6 Torr.…”

Structural and Optical Properties of Phase-Pure UO2, α-U3O8, and α-UO3 Epitaxial Thin Films Grown by Pulsed Laser Deposition

“…A laser energy density of 1.5 J/cm 2 was used for film growth. An imaged laser beam was used to get uniform laser energy density on the target. , The substrate temperature during the film growth was controlled in the range of 400–700 °C. The oxygen partial pressure during the film growth was varied from 1 × 10 –6 to 7 × 10 –1 Torr.…”