In this paper, we propose a novel route to generate monodisperse microbubbles (MB) in the range size of 3-10 µm. Using deep reactive ion etching, we designed several "terraces" emulsification devices with depths of 200-1000 nm. We performed characterizations and systematical investigations on critical parameters such as gas pressure, liquid flow rate, and chip geometry. We experimentally show here that MB size is mainly dependent on nanochannel height. The robust monodisperse MB production and the biocompatibility of the materials opens an opportunity to integrate such systems in the future diagnostics routines.