Pulsed laser deposition system for producing oxide thin films at high temperature

Abstract

A pulsed laser deposition system capable of raising substrate temperatures up to 1500 °C in oxygen atmosphere has been developed to grow oxide thin films with excellent crystalline quality. The high temperature is achieved by condensation onto a substrate of infrared light emitted from a halogen lamp through a ${\mathrm{SiO}}_{\mathrm{2}}$ rod serving as an optical guide. Deposition temperatures are regulated ranging from 1500 to 150 °C, under a partial oxygen pressure from 100 to ${\text{5×10}}^{\text{−6}} \mathrm{Pa}.$ An appropriate thermal insulation between the substrate holder and the surrounding components suppresses the heat flow inbetween, leading to a smooth rotation of the substrate holder and preventing the mechanical components from being oxidized. A high-precision five-axis alignment mechanism equipped with a substrate manipulator allows for the development of an application in coaxial impact-collision ion scattering spectroscopy. As a demonstrative experiment, highly oriented ${\mathrm{Ga}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ films, which are useful as deep ultraviolet transparent semiconductors, have been deposited on an ${\mathrm{Al}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{3}}$ (0001) single crystal substrate at 1000 °C under an oxygen pressure of ${\text{5×10}}^{\text{−5}} \mathrm{Pa}.$