Cubic boron phosphide epitaxy on zirconium diboride

• Published in: Journal of crystal growth Vol. 483; no. C; pp. 115 - 120
• Main Authors: Padavala, Balabalaji, Al Atabi, H., Tengdelius, L., Lu, J., Högberg, H., Edgar, J.H.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-02-2018; Elsevier BV; Elsevier
• Subjects: A1. Crystal morphology; A1. Defects; A1. Substrates; A3. Chemical vapor deposition processes; B2. Semiconducting III-V materials; Boron phosphides; Compressive properties; Electron microscopy; Epitaxial layers; Epitaxy; Group III-V semiconductors; Lattice parameters; Polycrystals; Refractory materials; Semiconductors; Single crystals; Substrates; Thermal expansion; Thermal stability; Transmission electron microscopy; Zirconium compounds; A3. Chemical vapor deposition processes; A1. Crystal morphology; B2. Semiconducting III-V materials; A1. Substrates; A1. Defects; Semiconducting III-V materials; Chemical vapor deposition processes; Crystal morphology; Substrates; Defects
• ISSN: 0022-0248; 1873-5002; 1873-5002
• DOI: 10.1016/j.jcrysgro.2017.11.014

•Cubic boron phosphide epitaxy on ZrB2/SiC and bulk ZrB2 single crystals was demonstrated.•Crystalline defects in the cubic boron phosphide BP films were identified.•The strain states of boron phosphide on the two types of substrates were established.
Cubic boron phosphide (BP) is one of the least studied III-V compound semiconductors, in part because it is difficult to prepare in high quality form. In this study, zirconium diboride (ZrB2) was studied as a potential substrate for BP epitaxial layers, because of its advantages of a low lattice constant mismatch and high thermal stability. Two types of substrates were considered: ZrB2(0 0 0 1) epitaxial films on 4H-SiC(0 0 0 1) and bulk ZrB2(0 0 0 1) single crystals. The optimal temperature for epitaxy on these substrates was 1100 °C; higher and lower temperatures resulted in polycrystalline films. The BP film/ZrB2 interface was abrupt as confirmed by cross-sectional transmission electron microscopy, attesting to the stability of ZrB2 under BP deposition conditions. The BP films were under compressive and tensile strain on ZrB2 and ZrB2/4H-SiC substrates, respectively, as determined by Raman spectroscopy, due to differences in the substrate/film coefficients of thermal expansion. This study suggests that with further optimization, ZrB2 can be an excellent substrate for BP epitaxial films.