3D integrated monolayer graphene–Si CMOS RF gas sensor platform. (December 2017)

• Record Type: Journal Article
• Authors: Mortazavi Zanjani, Seyedeh Maryam; Holt, Milo; Sadeghi, Mir Mohammad; Rahimi, Somayyeh; Akinwande, Deji
• Is Part Of: Npj 2D materials and applications. Volume 1(2017)
• Page Start: 1
• Page End: 9
• Publication Date: 2017-12
• Subjects: Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1038/s41699-017-0036-0
• Languages: English
• ISSNs: 2397-7132

Abstract

Abstract Integration of a complementary metal-oxide semiconductor (CMOS) and monolayer graphene is a significant step toward realizing low-cost, low-power, heterogeneous nanoelectronic devices based on two-dimensional materials such as gas sensors capable of enabling future mobile sensor networks for the Internet of Things (IoT). But CMOS and post-CMOS process parameters such as temperature and material limits, and the low-power requirements of untethered sensors in general, pose considerable barriers to heterogeneous integration. We demonstrate the first monolithically integrated CMOS-monolayer graphene gas sensor, with a minimal number of post-CMOS processing steps, to realize a gas sensor platform that combines the superior gas sensitivity of monolayer graphene with the low power consumption and cost advantages of a silicon CMOS platform. Mature 0.18 µm CMOS technology provides the driving circuit for directly integrated graphene chemiresistive junctions in a radio frequency (RF) circuit platform. This work provides important advances in scalable and feasible RF gas sensors specifically, and toward monolithic heterogeneous graphene–CMOS integration generally. Chemical sensing: monolithic CMOS integration of chemi-resistive graphene junctions The combination of monolayer graphene with a silicon-based CMOS platform results in a monolithically integrated gas sensor. A team led by Deji Akinwande at the University of Texas at Austin developed a graphene-based gas sensing platform that leverages the remarkable gas sensitivity of graphene and the well-established advantages of silicon technology. Using a commercially available 0.18 μm CMOS radio-frequency (RF) circuit, the authors fabricated graphene chemi-resistive junctions atop the CMOS readout circuit, whereby the interaction between gas molecules and graphene can be read as an output frequency while minimizing the number of post-processing steps. The built-in RF functionalities enable a direct wireless connection with the transducer and offer reduced flicker noise, as opposed to direct-current sensors.