Uniformity study of wafer-scale InP-to-silicon hybrid integration

In this paper we study the uniformity of up to 150 mm in diameter wafer-scale III–V epitaxial transfer to the Si-on-insulator substrate through the O2 plasma-enhanced low-temperature (300°C) direct wafer bonding. Void-free bonding is demonstrated by the scanning acoustic microscopy with sub-μm resolution. The photoluminescence (PL) map shows less than 1 nm change in average peak wavelength, and even improved peak intensity (4% better) and full width at half maximum (41% better) after 150 mm in diameter epitaxial transfer. Small and uniformly distributed residual strain in all sizes of bonding, which is measured by high-resolution X-ray diffraction Omega-2Theta mapping, and employment of a two-period InP–InGaAsP superlattice at the bonding interface contributes to the improvement of PL response. Preservation of multiple quantum-well integrity is also verified by high-resolution transmission electron microscopy.