Quantitative evaluation of growth-induced residual stress in InP epitaxial micromechanical structures

We have investigated the residual stress distribution and its relation to the presence of impurity atoms in InP layers grown by metalorganic vapor phase epitaxy (MOVPE) on top of lattice-matched GaInAs layers. The homogeneous and gradient components of the stress have been directly measured using highly sensitive micromechanical test structures. Secondary ion mass spectrometry depth profiling of the composition evidenced that residual As and Ga atoms are present throughout the relatively thick (>0.5 μm) InP layers. Our investigations show that the distribution of these impurities accounts for the measured residual stress in the layers and, at the same time, it is specific to the MOVPE growth technique.