High-yield large-scale suspended graphene membranes over closed cavities for sensor applications

TL;DR

This paper presents a novel 'hot and dry' transfer process for large-scale suspended graphene membranes over sealed cavities, achieving higher yields and enabling sensor applications with improved fabrication techniques.

Contribution

The work introduces a high-temperature, dry transfer method that significantly enhances the yield and quality of large-area suspended graphene membranes compared to previous techniques.

Findings

Higher yields of intact graphene membranes achieved

Neural-network-based detection confirms high fabrication success

Suspended membranes successfully used as pressure sensors

Abstract

Suspended membranes of monoatomic graphene exhibit great potential for applications in electronic and nanoelectromechanical devices. In this work, a "hot and dry" transfer process is demonstrated to address the fabrication and patterning challenges of large-area graphene membranes on top of closed, sealed cavities. Here, "hot" refers to the use of high temperature during transfer, promoting the adhesion. Additionally, "dry" refers to the absence of liquids when graphene and target substrate are brought into contact. The method leads to higher yields of intact suspended monolayer CVD graphene and artificially stacked double-layer CVD graphene membranes than previously reported. The yield evaluation is performed using neural-network-based object detection in SEM images, ascertaining high yields of intact membranes with large statistical accuracy. The suspended membranes are examined by Raman tomography and AFM. The method is verified by applying the suspended graphene devices as piezoresistive pressure sensors. Our technology advances the application of suspended graphene membranes and can be extended to other two-dimensional (2D) materials.