Misorientation dependence of zinc incorporation in GaAs

• Published in: Journal of crystal growth 1994-09, Vol.142 (3), p.292-297
• Main Authors: Anders, M.J., Hageman, P.R., Giling, L.J.
• Format: Article
• Language: English
• Subjects: Chemical vapor deposition (including plasma-enhanced cvd, mocvd, etc.); Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Defects and impurities: doping, implantation, distribution, concentration, etc; Exact sciences and technology; Materials science; Methods of deposition of films and coatings; film growth and epitaxy; Physics; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Thin film structure and morphology
• ISSN: 0022-0248; 1873-5002
• DOI: 10.1016/0022-0248(94)90334-4

Doping studies of zinc have been carried out for metalorganic chemical vapour deposition (MOCVD) grown GaAs, with diethyl zinc as precursor. The zinc incorporation has been studied as a function of the zinc input mole fraction, growth temperature and substrate misorientation. It is found that the zinc incorporation on (001) substrates misoriented towards [0 1 1] and [011] directions showed a consistent and similar dependence on the misorientation angle at various zinc input mole fractions, with an observed minimum in the Zn-incorporation at 4° off. The observed temperature dependence leads to a apparent activation energy of −59 kcal/mol for zinc incorporation which is attributed to the enthalpy involved in the formation of two boundsduring the incorporation. The dependence on the misorientation angle is explained by competition between the influence of “step trapping” at lower misorientation (and higher step velocities) and the increase of available kinksites at higher misorientation angles.