Wafer-Scale Integration Of Graphene-Based Photonic Devices

Graphene and related materials can lead to disruptive advances in next-generation photonics and optoelectronics. The challenge is to devise growth, transfer and fabrication protocols providing high (>= 5000 cm(2) V-1 s(-1)) mobility devices with reliable performance at the wafer scale. Here, we present a flow for the integration of graphene in photonics circuits. This relies on chemical vapor deposition (CVD) of single layer graphene (SLG) matrices comprising up to similar to 12000 individual single crystals, grown to match the geometrical configuration of the devices in the photonic circuit. This is followed by a transfer approach which guarantees coverage over similar to 80% of the device area, and integrity for up to 150 mm wafers, with room temperature mobility similar to 5000 cm(2) V-1 s(-1). We use this process flow to demonstrate double SLG electro-absorption modulators with modulation efficiency similar to 0.25, 0.45, 0.75, 1 dB V-1 for device lengths similar to 30, 60, 90, 120 mu m. The data rate is up to 20 Gbps. Encapsulation with single-layer hexagonal boron nitride (hBN) is used to protect SLG during plasma-enhanced CVD of Si3N4, ensuring reproducible device performance. The processes are compatible with full automation. This paves the way for large scale production of graphene-based photonic devices.