Wafer-Scale Integration of Graphene-Based Photonic Devices

Abstract

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 ∼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 ∼80% of the device area, and integrity for up to 150 mm wafers, with room temperature mobility ∼5000 cm 2 V –1 s –1 . We use this process flow to demonstrate double SLG electro-absorption modulators with modulation efficiency ∼0.25, 0.45, 0.75, 1 dB V –1 for device lengths ∼30, 60, 90, 120 μm. 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 Si 3 N 4 , ensuring reproducible device performance. The processes are compatible with full automation. This paves the way for large scale production of graphene-based photonic devices.

High-responsivity graphene photodetectors integrated on silicon microring resonators

“…high-speed (>200 GHz) 6 , 7 and broadband (ultraviolet to far-infrared) 8 , 9 operation that could lift bandwidth (BW) (~100 GHz) 10 , 11 and spectral (<1600 nm) 12 limitations of existing technologies, such as Ge/Si 13 , 14 and InGaAsP/InP 15 , 16 . A variety of waveguide (WG)-integrated SLG-based photonic devices have been reported 17 – 34 , including electro-absorption (EAMs) 17 – 19 and electro-refraction modulators (ERMs) 20 , optical switches 4 , 21 , and photodetectors (GPDs) 22 – 33 . SLG and layered materials can be integrated with passive Si photonic WGs 22 – 27 or any other passive WG technology 4 , including Si 3 N 4 29 , 34 , 35 , sapphire 36 , Ge 37 , and polymers 38 , 39 , extending the spectral range and scope of possible applications 37 , 40 .…”

Graphene overcoats for ultra-high storage density magnetic media

“… 47 , we showed that it is possible to achieve high mobilities ~30,000 cm 2 V/s at room temperature in wet transferred, polycrystalline 1LG. Thus, scalable processes, such as wet transfer, can be used for integration and packaging 47 , 48 . All these characteristics make 1LG promising as a protective overcoat for both existing and HAMR-based technologies.…”

Modeling Photodetection at the Graphene/Ag2S Interface

“…The membrane (supported by the frame) was then laminated to the target substrate in air using a dedicated transfer setup. [75] Finally, the polymer was removed in acetone and isopropanol.…”