Large-area integration of two-dimensional materials and their heterostructures by wafer bonding

Abstract

Integrating two-dimensional (2D) materials into semiconductor manufacturing lines is essential to exploit their material properties in a wide range of application areas. However, current approaches are not compatible with high-volume manufacturing on wafer level. Here, we report a generic methodology for large-area integration of 2D materials by adhesive wafer bonding. Our approach avoids manual handling and uses equipment, processes, and materials that are readily available in large-scale semiconductor manufacturing lines. We demonstrate the transfer of CVD graphene from copper foils (100-mm diameter) and molybdenum disulfide (MoS2) from SiO2/Si chips (centimeter-sized) to silicon wafers (100-mm diameter). Furthermore, we stack graphene with CVD hexagonal boron nitride and MoS2 layers to heterostructures, and fabricate encapsulated field-effect graphene devices, with high carrier mobilities of up to $$4520\;{\mathrm{cm}}^2{\mathrm{V}}^{ - 1}{\mathrm{s}}^{ - 1}$$ 4520 cm 2 V − 1 s − 1 . Thus, our approach is suited for backend of the line integration of 2D materials on top of integrated circuits, with potential to accelerate progress in electronics, photonics, and sensing.

Graphene in 2D/3D Heterostructure Diodes for High Performance Electronics and Optoelectronics

“…Among the main challenges toward the commercialization of graphene‐based diodes are the lack of growth and transfer technologies for graphene and the integration technology into conventional semiconductor platforms. Progress in the quality and integrability of large‐area grown graphene is expected to improve over the coming years [ 123 ] and enable further improvements in key device characteristics such as cutoff frequency, current levels or responsivity. This may pave the way for graphene to become an integral part of future commercial electronic and optoelectronic components.…”

Fabrication Methods for Integrating 2D Materials

“…[334,336,495] To meet the requirements of largearea production, a universal strategy was developed to fabricate two-layer heterostructures with a lateral size up to 100 mm. [496] Fig. 11(a) shows the corresponding fabrication steps, where a bottom 2D film was first prepared on a commercial integrated wafer with a bisbenzocyclobutene adhesive layer and another 2D film was then stacked onto the first one after a wafer bonding process.…”

Electron beam lithography for direct patterning of MoS2 on PDMS substrates

“…At the same time 2D materials are particularly sensitive to contamination and residues, which can introduce defects, doping and seriously degrade their optical and electronic properties. [4][5][6][7] Moreover, many cleaning techniques commonly used in silicon industry, such as strong acids or oxygen plasma, can no longer be used for 2D materials processing.…”