Metal-insulator-semiconductor capacitors with water-containing hexagonal mesoporous silica (MCM-41) dielectric and high values of capacitance per unit area
There are many studies on the synthesis and structure of mesoporous silica, but few reports on mesoporous silica-based electronic devices using planar technology. Fabrication of low-k insulator films from mesoporous silica has been investigated for years. Trapped water is a nuisance for those intending to use mesoporous silica films as low-k materials, but may be beneficial for other applications. In this work, we fabricated Si metal-insulator-semiconductor capacitors (MIS) with a hexagonal mesoporous silica (MCM-41) film as the dielectric and studied their electrical characteristics. We show that water confined within the dielectric is associated with high values of capacitance per unit area (approximately 1 μF cm−2 at 100 Hz) and frequency dispersion of the accumulation capacitance. These devices hold potential for the development of high value MIS capacitors, sensors and biosensors.