Interfacing Ultraclean Graphene with Solid-State Devices

TL;DR

This paper presents a catalytic method using platinum metals to achieve ultraclean graphene interfaces with solid-state devices, enabling contamination-free integration for technological applications.

Contribution

A novel catalytic annealing process using platinum metals to remove polymer capping, resulting in ultraclean graphene interfaces with solid-state devices.

Findings

Successful removal of polymer capping via platinum catalysis

Demonstration of clean graphene interfaced with silicon wafers

Production of multi-layer graphene sheets with high cleanliness

Abstract

Interfacing graphene with solid-state devices and maintaining it free of contamination is a crucial step towards a functioning device, be it a semiconductor structure or any other device for technological applications. We take advantage of the catalytic properties of platinum metals to completely remove the polymer capping after the transfer of macroscopic graphene sheets to a solid-state device. For that purpose a platinum metal coated structure is brought in close proximity with the polymer capping. Subsequent annealing in air at a temperature between 175 and 350{\deg}C actuates a complete catalytic removal of the polymer. Finally, the platinum metal catalyst is removed revealing ultra clean graphene interfaced with an arbitrary device. Experiments to interface macroscopic graphene layers with oxidized silicon wafers demonstrate the general applicability of this approach. In repeating the procedure, multi-layer graphene sheets can also be produced. Direct evidence for the latter is provided by optical images of three overlapping graphene sheets. The exceeding level of cleanliness of the graphene is examined on the nanometer scale by means of low-energy electron transmission microscopy.