LAUSR

Abstract Vertically oriented graphene structures have a high specific surface area which makes them potential candidates for realization of various devices. On their basis, supercapacitors, lithium-ion batteries, absorbing coatings and bolometers, gas and electrochemical sensors, and other devices have been demonstrated. At the same time, such structures for conventional capacitors remain unexplored. In this research the fabrication technology of quasi three-dimensional capacitors based on metal/carbon nanowalls/insulator/metal structure (MCNWIM) are demonstrated. Carbon NanoWalls (CNWs) were used as a base electrode to increase the specific surface area of capacitors. Uniform dielectric and metal layers of aluminum oxide (AlOx) and titanium nitride (TiNx) were deposited by thermal atomic layer deposition (ALD) and plasma-enhanced atomic layer deposition (PEALD). A comparative analysis of capacitors with and without a carbon nanostructure has been performed. The influence of dielectric thickness on the capacitance density as well as dependencies of breakdown voltage on the surface area were experimentally observed. The maximum capacitance density was 3.6 μF/cm2 at the AlOx thickness of 10 nm, which is 4.7 times higher than the values of capacitors without carbon nanostructure. The investigated structures were manufactured on four-inch silicon wafers that provide the possibility of the mass production of capacitors based on CNWs.