Anomalous arsenic diffusion at InGaAs/InP interface

The anomalous arsenic (As) diffusion at the In0.53Ga0.47As/InP interface grown by solid source molecular beam epitaxy has been reported in this work. Heterointerface samples were grown using group-V switches of P2 to As2 or to As4. High-resolution x-ray diffraction (XRD), photoluminescence (PL), 3D atom probe (3DAP) and high-angle annular dark field scanning transmission electron microscopy (HAADF-STEM) data have shown that, an up to hundred-nanometer-thick composition-graded InAs y P1-y layer formed in the InP buffer layer for the sample grown by P2 to As2. This observation demonstrates a rapid replacement of P by As atoms at the heterointerface and a deep As diffusion into the lower InP buffer. In contrary, a sharper heterointerface without the composition-graded layer was obtained in the sample grown using P2 to As4. These findings give insight into the distinct properties of different As species in the InGaAs/InP interface growth.