Influence Of Trench Width On Iii-V Nucleation During Inp Selective Area Growth On Patterned Si(001) Substrates

The selective area growth (SAG) of InP by metal-organic vapor phase epitaxy (MOVPE) inside shallow trench isolation (STI) trenches of various widths ranging from nominally 20nm to 500nm on Si(001) substrates is investigated by SEM and AFM in this report. With different growth time, the similar morphology evolution stages in both wide and narrow trenches are identified. Nevertheless, by comparing 40nm wide trenches to 150nm ones, the coalescence stage of islands is delayed in narrow trenches, which leads to a discontinuous topology with sufficiently long time growth. We proposed a model to study the possible impact of trench width on the average inter-island distance, which can be a main mechanism for the evolution delay in narrow trenches.