Vapor-Phase Chemical Etching of Silicon Assisted by Graphene Oxide for Microfabrication and Microcontact Printing
Wataru Kubota, Ryoya Yamaoka, Toru Utsunomiya, Takashi Ichii, Hiroyuki Sugimura
Abstract
Chemical etching of silicon assisted by a number of catalysts is attracting increasing attention in the fabrication of silicon micro–nanostructures. In practical applications, metal-free catalysts, including carbon materials, have been focused on as alternative materials for the assisted etching of silicon. Although this anisotropic etching process is suitable for the fabrication of silicon micro–nanostructures due to its simplicity and cost effectiveness, a number of challenges remain, such as the formation of a porous layer and peeling of the catalyst by the gases produced during the etching process. We herein report vapor-phase etching assisted by graphene oxide and its mechanism in terms of reaction kinetics. By optimizing etching conditions, graphene oxide enhances the etching reaction in the vapor phase without the formation of a porous layer. We also demonstrated the formation of micrometer-sized pores in the desired areas by combining the microcontact printing of graphene oxide with silicon etching in the vapor phase.