Crystallographic plane dependent Fe and Si dopant incorporation and activation in InP



Various crystallographic planes are exposed when growing along mesa sidewalls during metalorganic vapor phase epitaxy. Dopant incorporation and activation on these higher index surfaces can be quite different from that observed on (001) surfaces. Incorporation and activation of Si and Fe in MOVPE grown InP on (001), (110), and (311)A and B surfaces are reported. The Si donor concentration is higher on the P-terminated B surface than the A surface while the opposite behavior is observed for Fe incorporation. In the fabrication of optoelectronic devices, it must be remembered that it is the carrier concentration, that is, activated atomic species, that is relevant for device performance and not the incorporation of atomic species alone. Activation of Si is >1 on all surfaces; however, Fe is shown to be an effective compensating species only on the (001) and (311)A crystallographic surfaces. Data for the presence of oscillations in the iron concentration on (001) surfaces are also reported. The active Fe concentration is shown to be related to the Fe atomic concentration relative to the donor density on the different crystallographic surfaces, suggesting that Fermi level position sets a limit to the fraction of Fe centers which are electrically active as a deep trap. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)