AUTHOR=Li Yue , Zhou Yunxia , Deng Yanrong , Ta Shiwo , Yang Zhao , Li Haiou , Sun Tangyou , Chen Yonghe , Zhang Fabi , Fu Tao , Wangyang Peihua , Zhu Jun , Zeng Lizhen , Liu Xingpeng 

TITLE=Formation and Effect of Deposited Thin TiO2 Layer With Compressive Strain and Oxygen Vacancies on GaAs (001) Substrate

JOURNAL=Frontiers in Materials

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/materials/articles/10.3389/fmats.2022.846428

DOI=10.3389/fmats.2022.846428

ISSN=2296-8016

ABSTRACT=<p>The integration of metal oxides and GaAs semiconductors is quite attractive for its potential applications, but interfacial diffusion and lattice mismatch usually cause huge challenges toward achieving high-performance electronic devices. In this article, we reported a thin layer of epitaxial TiO<sub>2</sub> (110) on a GaAs (001) substrate with significant compressive strain, lattice distortion, and oxygen vacancies, where the oxygen vacancies proved to be the critical factor to induce the compressive strain and lattice distortion. In this case, the lattice mismatches between this compressed TiO<sub>2</sub> (110) and GaAs (001) surface were calculated to be as small as 1.3 and 0.24% along the [110] and [001] orientations of TiO<sub>2</sub>, respectively. Further, no Ga-oxides or As-oxides were found at the interface, indicating that the TiO<sub>2</sub> layer inhibited the diffusion of Ga and As atoms effectively. In summary, TiO<sub>2</sub> film can be grown epitaxially on GaAs (001) substrates with non-negligible compressive strain, lattice distortion, oxygen vacancies, and a high-quality interface. This study also provides an approach to integrate different functional oxides on TiO<sub>2</sub>-buffered GaAs for various GaAs-based electronic devices with higher reliability and performance.</p>