Application of an Sb Surfactant in InGaAs Nano-ridge Engineering on 300 mm Silicon Substrates

Nano-ridge engineering (NRE) is a novel heteroepitaxial integration approach for III-V devices on Si substrates. It starts with selective area growth in narrow trenches for misfit defect trapping. Growth is then continued out of the trenches to engineer the nano-ridges (NRs). Different device concepts such as lasers and transistors have been demonstrated using box-shaped NRs. To widen the field of applications, NRE is extended to the alloy In0.53Ga0.47As. The In and Ga incorporation depends strongly on the exposed NR facets; hence, composition fluctuation has to be limited to avoid misfit defect formation. Growth conditions, which typically ensure the formation of a box-shaped NR, result in nonuniform InGaAs NR lines. For the first time, an Sb surfactant was applied in NRE to achieve uniform and box-shaped InGaAs NRs. A detailed structural investigation shows that the presence of Sb improves the In-distribution in the NR but reduces the gliding efficiency of threading dislocations, which is essential for the misfit defect reduction inside the trench. A two-step growth approach was developed to overcome this drawback and to still benefit from the desired impact of a surfactant on the InGaAs box-formation, which ensures InGaAs NRs with high crystal quality.