Effect of antimony on growth mode and properties of thick InGaN layers

• First study on the effect of antimony (Sb) on growth of thick InGaN layers by MOVPE.
• Identification of two growth regimes dominated by {101¯1} and {0001} crystal facets.
• Increasing surface coverage of Sb adatoms increased indium adatom desorption.
• Proposed surfactant behavior of Sb not true (Sb content of up to 0.74% found).
• Sb incorporation significantly affects structural and luminescence properties.

A comprehensive study on the effect of antimony on growth mode and crystal properties of thick InGaN layers grown by metal-organic vapor phase epitaxy is presented. Two growth regimes are identified by atomic force microscopy: while already minor antimony precursor flux induces the stabilization of {101¯1} facets, the application of increased fluxes leads to the growth of nanoscopic islands which suppresses the typically observed V-pit formation and thus decreases the layer roughness. Further on, high incorporation rates of antimony cause to concentrations of up to 0.74%, at standard InGaN growth conditions, are revealed. The obtained results on the impact of antimony incorporation provide evidence that the generally assumed true surfactant behavior of antimony for InGaN growth has to be reconsidered since it significantly affects structural and luminescence properties.