The contribution of AsH3: Pre-flow and V/III ratio effects on heteroepitaxially grown GaAs/Ge. (April 2019)

• Record Type: Journal Article
• Authors: Demir, Ilkay
• Is Part Of: Superlattices and microstructures. Volume 128(2019)
• Page Start: 1
• Page End: 8
• Publication Date: 2019-04
• Subjects: GaAs -- Arsine -- Buffer layer -- Ge -- MOVPE; Superlattices as materials -- Periodicals; Microstructure -- Periodicals; Semiconductors -- Periodicals; Superréseaux -- Périodiques; Microstructure (Physique) -- Périodiques; Semiconducteurs -- Périodiques; 621.38152
• DOI: 10.1016/j.spmi.2019.01.007
• Languages: English
• ISSNs: 0749-6036

Abstract

Abstract: We report the effects of AsH3 (arsine) on morphological, structural, optical and crystalline quality of MOVPE (metal organic vapor phase epitaxy) grown GaAs/Ge heterostructures. AsH3 pre-flow supplied on Ge substrate to have As atoms as a first atomic layer on the surface of Ge substrate. Additionally, the V/III ratio effects of LT-GaAs buffer layer, grown on arsenized Ge substrate, have been analyzed to have reduced APBs (anti-phase boundaries) in the interface between epilayer and Ge substrate. It has been considered that the optimal AsH3 pre-flow duration and V/III ratio of GaAs buffer layer extremely influence the effects of APBs even we have used miss-cut Ge substrate and grown by two-step growth technique to obtain double atomic step. It is shown that without AsH3 pre-flow the surface of GaAs epilayer becomes rougher while it is optically smooth under the longer AsH3 pre-flow. On the other hand, even the surface situation does not change with longer AsH3 pre-flow the structural, optical and crystalline qualities become worse because of the possible presence vacancies of created during the growth. Similar behavior has been observed for the V/III effects of GaAs buffer layer and it has resulted in low full width at half maximum of high-resolution X-ray diffraction and high photoluminescence peak intensity for the optimal V/III ratio. Highligths: High quality GaAs epilayers were grown by MOVPE on miscut Ge substrates. AsH3 pre-flow supplied on Ge to have As atoms as a first atomic layer on the surface and effects are investigated. V/III ratio effects of GaAs buffer layer on heterostructure properties have been analyzed under the fixed flow of TMGa.