Improvements in epitaxial lateral overgrowth of InP by MOVPE

Indium phosphide and silicon play important and complementary roles in communications wavelength photonic devices. Realizing high quality coalesced epitaxial lateral overgrown (ELO) InP films on Si could greatly reduce cost and encourage the proliferation of energy efficient photonic integrated circuits in consumer devices. By adjusting a parallel line ELO mask and metalorganic vapor phase epitaxial growth conditions, we have fully coalesced and partially coalesced epitaxial lateral overgrowth of InP on InP substrates and Si substrates having strain relaxed III/V buffer layers, respectively. Extended defects were investigated using transmission electron microscopy and were not found to originate at the coalescence of the nearest neighbor growth fronts for linear parallel growth windows oriented 60° off of [0−11] when using a high V/III ratio of 406. In addition, narrowly separated linear parallel growth windows having a large aspect ratio of 7.5 were seen to inhibit the upward propagation of stacking faults through several neighboring openings. Elimination of these two defect sources would leave primarily the challenge of optimizing the morphology of the overgrown InP as a substantial barrier to achieving coalesced ELO InP of sufficient quality for photonic device applications. •Coalescence defects correlated to ELO morphological features by plan view TEM and SEM.•Absence of defects observed by TEM in coalesced homoepitaxial optimized MOVPE ELO.•Partially coalesced heteroepitaxial ELO using a mask having a high aspect ratio of 7.5.•TEM of heteroepitaxial ELO showing >30 consecutive defect free coalesced regions.•Inhibition of stacking fault propagation into heteroepitaxial ELO windows were observed.