Study of GaP Nucleation Layers Grown on Si by Plasma‐Enhanced Atomic Layer Deposition

• Published in: Physica status solidi. A, Applications and materials science Applications and materials science, 2020-02, Vol.217 (4), p.n/a
• Main Authors: Gudovskikh, Alexander S., Uvarov, Alexander. V., Morozov, Ivan A., Bukatin, Anton S., Baranov, Artem I., Kudryashov, Dmitry A., Kalyuzhnyy, Nikolay A., Mintairov, Sergey A., Zubkov, Vasily I., Yakovlev, George E., Kleider, Jean-Paul
• Format: Article
• Language: English
• Subjects: Atomic layer epitaxy; Defect annealing; Epitaxial growth; GaP; GaP/Si heterojunctions; Heat treatment; Heterojunctions; Hydrogen plasma; Interface stability; Metalorganic chemical vapor deposition; Nucleation; Photoelectric effect; Photoelectricity; Plasma; plasma-enhanced atomic layer deposition; Properties (attributes); Silicon substrates; solar cells; Thermal stability
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201900532

The capability of plasma‐enhanced atomic layer deposition (PE‐ALD) for the formation of GaP nucleation layers on Si substrates for further epitaxial growth is explored. The possibility of epitaxial growth of GaP by metalorganic vapor phase epitaxy (MOVPE) on templates prepared by PE‐ALD GaP/Si is demonstrated. The structural and electronic properties of the interfaces between the GaP nucleation layer and the Si substrate as well as their thermal stability are studied. Initially, the GaP/Si structures obtained by PE‐ALD without additional hydrogen plasma exhibit better photoelectric properties compared with that fabricated with high H2 plasma power that induces the formation of defects in the silicon subsurface layer. Annealing at temperatures of 550–600 °C leads to a decrease in the defect concentration created by the hydrogen plasma. Thus, after annealing, the GaP/Si interfaces fabricated by both types of PE‐ALD processes exhibit similar quality. Thermal treatment of the GaP/Si structures at temperatures of 725–750 °C leads to the diffusion of phosphorus from GaP into Si and to the formation of an isotype n‐GaP/n–p‐Si heterojunction with improved photoelectric properties. High‐temperature stability of the GaP/Si interface fabricated by PE‐ALD is essential for its prospective use for GaP/Si templates. The possibility to form GaP nucleation layers on Si substrates by plasma‐enhanced atomic layer deposition (PE‐ALD) at low temperature for further epitaxial growth by metalorganic vapor phase epitaxy (MOVPE) is demonstrated. The structural and electronic properties of the interfaces between GaP nucleation layer and Si substrate as well as their thermal stability are studied.