RF magnetron sputter deposition of Ga-doped BiCuSeO films

Abstract

In this research we attempted to grow epitaxial BiCu0 95Ga0 05SeO (BCSO:Ga) thin films on SrTiO?3(100) single crystal substrates for applications as the bottom electrode on the popular substrate SrTiO3 The films were grown by RF magnetron sputtering method The Ga doping effects on the film growth of BiCuSeO and its thermal stability were investigated The results of BCSO:Ga films show that as the shutter closing time decreases the BiSe heterophase appears As the shutter closing time increases the BiSe heterophase can be removed A single-phase BCSO:Ga thin film was successfully grown by RF magnetron sputtering method in this research In addition we can observe the BCSO:Ga thin films have (001) preferred orientation at a lower substrate temperature (300 oC 350 oC) Secondary electron images can observe the cubic crystal at 350 oC In order to investigate the thermal stability of BCSO:Ga thin films a continuous process was used to prepare SrTiO3 substrate/BCSO:Ga/BiFeO3(BFO) films structure Under the substrate temperature of 500 oC the results can still observe the BCSO:Ga films As the sputtering time increases the intensity of BCSO:Ga diffraction signal decreases Comparing with pure BCSO thin films BCSO:Ga thin films indeed improve its thermal stability But it does not prevent the volatilization of Bi the effect is still limited

Date of Award	2020
Original language	English
Supervisor	Xiao-Ding Qi (Supervisor)