Low temperature (200°C) direct bonding of InP and Si 3N 4 coated silicon wafers using oxygen plasma surface treatment has been demonstrated, which transfers InP-based thin films onto Si substrates for heterogeneous photonic integration. Pulling test shows a high bonding energy comparable to the InP fracture energy. The high crystalline quality of the bonded thin film is preserved, as evident from photoluminescence and high resolution X-ray diffraction measurements. Cross-sectional transmission electron microscopy shows an intimately bonded interface with no observable defects generated near the bonded interface. A thin layer of amorphous oxide about 6 nm thick has been detected at the bonded interface. The hydrophilic interface obtained by oxygen plasma activation helps to achieve high quality bonding. Due to the high thermal conductivity of Si 3N 4, these high quality bonded structures of InPSi with Si 3N 4 sandwiched in-between have potential applications in enhancing performance of high power Si photonic integrated devices.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Renewable Energy, Sustainability and the Environment
- Surfaces, Coatings and Films
- Materials Chemistry