Verification of singular plane formation in CdTe homoepitaxy

• Published in: Journal of crystal growth Vol. 217; no. 1; pp. 102 - 108
• Main Authors: Yoshioka, Yasushi, Shimizu, Kazuhiro, Takagaki, Katsuhiko, Kasuga, Masanobu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2000; Elsevier
• Subjects: AFM; CdTe; Condensed matter: structure, mechanical and thermal properties; Defects and impurities: doping, implantation, distribution, concentration, etc; Exact sciences and technology; Homoepitaxy; Physics; Singular surface plane; Step growth; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology; Twin-formation criteria; Singular surface plane; AFM; Homoepitaxy; Twin-formation criteria; CdTe; Step growth; Crystal twin; Atomic force microscopy; Inorganic compounds; Epitaxial layers; Semiconductor materials; Sublimation; Transition element compounds; Supersaturation; Crystal growth from vapors; Step; Experimental study; Cadmium tellurides
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/S0022-0248(00)00469-3

In homoepitaxial growth of CdTe, twin formation is affected by the orientation of the substrate and the supersaturation of vaporized source materials. In a microscopic sense, increasing step density and decreasing supersaturation is presumed to promote step flow growth mode and to suppress spontaneous nucleation on step terraces. To verify the step structure and specify the characteristic planes on the growing surface of CdTe layers, we observed the surface of the grown layers with atomic-force microscope (AFM) and measured the tilt angle of characteristic planes for the layers on CdTe (3 1 1)A, B and (2 1 1)A, B substrates. We found characteristic facets with certain tilt angles against substrate surface among wide stepped or rippled region. In the case of low-supersaturation growth on the (2 1 1) substrate, the (1 0 0) facet was proved to be the singular plane. In the cases of growth on (3 1 1) and (2 1 1) with high supersaturation, the (1 1 1) facet is also singular as well as the (1 0 0) plane. The measured width of the zonal facets was several hundreds times larger than the step terrace expected in monolayer step model and was close to terrace width estimated previously by twin-formation criteria.