Metal-Isolator-Metal Varactor Based on Inkjet-Printed Tunable Ceramics

This paper presents a new method for the fabrication of tunable multilayer components based on inkjet printing. Inkjet printing is a low-cost technology for selective film fabrication and has a high potential for the preparation of tunable dielectric layers. Exemplary tunable metal-isolator-metal (MIM) capacitors composed of inkjet-printed Barium-Strontium-Titanate (BST) and photolithographically structured metallic electrodes. Compared to coplanar capacitors, such varactors require significantly lower DC-voltage for tuning. By applying 20V across 1um-thick BST film, a tunability of 37% is achieved at 10GHz. The low-cost inkjet printing technology has shown a high potential for the preparation of tunable dielectric thick-films.