title: Self-organized growth of graphene nanomesh with increased gas sensitivity.
abstract: A bottom-up chemical vapor deposition (CVD) process for the growth of graphene nanomesh films is demonstrated. The process relies on silicon nanospheres to block nucleation sites for graphene CVD on copper substrates. These spheres are formed in a self-organized way through silicon diffusion through a 5 μm copper layer on a silicon wafer coated with 400 nm of silicon nitride. The temperature during the growth process disintegrates the Si3N4 layer and silicon atoms diffuse to the copper surface, where they form the nanospheres. After graphene nanomesh growth, the Si nanospheres can be removed by a simple hydrofluoric acid etch, leaving holes in the graphene film. The nanomesh films have been successfully transferred to different substrates, including gas sensor test structures, and verified and characterized by Auger, TEM and SEM measurements. Electrical/gas-exposure measurements show a 2-fold increase in ammonia sensitivity compared to plain graphene sensors. This improvement can be explained by a higher adsorption site density (edge sites). This new method for nanopatterned graphene is scalable, inexpensive and can be carried out in standard semiconductor industry equipment. Furthermore, the substrates are reusable.
authors: University of Siegen, Department of Electrical Engineering and Computer Science, Hölderlinstr. 3, 57076 Siegen, Germany and Infineon Technologies AG, 93049 Regensburg, Germany. Matthias.Koenig@infineon.com.
authors: Matthias
authors: M
authors: König
authors: Infineon Technologies AG, 93049 Regensburg, Germany. Matthias.Koenig@infineon.com.
authors: Günther
authors: G
authors: Ruhl
authors: Infineon Technologies AG, 93049 Regensburg, Germany. Matthias.Koenig@infineon.com.
authors: Joerg-Martin
authors: JM
authors: Batke
authors: University of Siegen, Department of Electrical Engineering and Computer Science, Hölderlinstr. 3, 57076 Siegen, Germany.
authors: Max C
authors: MC
authors: Lemme