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

Abstract

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.