Ultra-thin DVS-BCB adhesive bonding of III-V wafers, dies and multiple dies to a patterned silicon-on-insulator substrate

Abstract

Heterogeneous integration of III-V semiconductor materials on a silicon-on-insulator (SOI) platform has recently emerged as one of the most promising methods for the fabrication of active photonic devices in silicon photonics. For this integration, it is essential to have a reliable and robust bonding procedure, which also provides a uniform and ultra-thin bonding layer for an effective optical coupling between III-V active layers and SOI waveguides. A new process for bonding of III-V dies to processed siliconon-insulator waveguide circuits using divinylsiloxane-bis-benzocyclobutene (DVS-BCB) was developed using a commercial wafer bonder. This "cold bonding" method significantly simplifies the bonding preparation for machine-based bonding both for die and wafer-scale bonding. High-quality bonding, with ultra-thin bonding layers (<50 nm) is demonstrated, which is suitable for the fabrication of heterogeneously integrated photonic devices, specifically hybrid III-V/Si lasers. K. Mayora, "Novel three-dimensional embedded SU-8 microchannels fabricated using a low temperature full wafer adhesive bonding," J. Micromech. Microeng. 14(7), 1047-1056 (2004

Membrane-Based Receiver/Transmitter for Reconfigurable Optical Wireless Beam-Steering Systems

“…The entire membrane is bonded onto a silicon wafer using benzocyclobutene (BCB) polymer [10]. The thickness of the optical buffer layer (1850 nm in total, combining SiO 2 and BCB layers) is optimized to avoid light leakage into the substrate and to obtain efficient coupling between grating couplers and optical fibers.…”

Silicon-Based Photonic Integration Beyond the Telecommunication Wavelength Range

“…This process is well developed for InP-based epitaxy for operation in the telecommunication window [27] and has been ported to transfer GaSb-based epitaxy as well. In our work we use an adhesive bonding approach based on DVS-BCB, which is forgiving in terms of silicon and III-V wafer quality (surface roughness and contamination).…”

Low-Temperature Bonding for Silicon-Based Micro-Optical Systems

“…The bonding temperature is dependent on the type of adhesive used and can vary from room temperature (for UV cured adhesives) to 100 °C. One of the commonly used adhesive in photonic integration is divinylsiloxane-bis-benzocyclobutene (DVS-BCB), because it has a low curing temperature, high degree of planarization, high optical transmissivity, good thermal stability, excellent chemical stability, and low moisture absorption [115]. The process flow of BCB adhesive bonding is shown in Figure 11.…”