Wet transfer process for MEMS freestanding PMMA/Graphene membrane development

Abstract

Process of transferring poly (methyl methacrylate) (PMMA)/Graphene layer to form a freestanding membrane requires a proper method to ensure that the membrane is well suspended with high graphene coverage. This paper demonstrates a method for transferring PMMA/Graphene onto an etched silicon cavity, which forms freely suspended graphene using ferric chloride (FeCl3) solution. The characterisation was performed with an optical microscope and Raman spectroscopy to examine the quality of the transferred PMMA/Graphene membrane. Wet transfer process by FeCl3 etchant was successfully applied to develop a freestanding PMMA/Graphene membrane on a silicon etch cavity. From the study, 0.5M concentration of FeCl3 etchant is more suitable to be applied compared to 1.0 M in order to form a freestanding PMMA / Graphene membrane.