Patent attributes
A varactor on a substrate is provided. The varactor comprises a bottom electrode, an upper electrode, a first dielectric layer and a conductive layer. The bottom electrode has several doped regions arranged in the substrate as an array with several rows and several columns, wherein the doped regions in adjacent columns are arranged alternatively. The upper electrode is located over the substrate and the upper electrode is composed of several electrode locations and has several openings, wherein each opening exposes the corresponding doped region. Furthermore, each electrode location is surrounded by three doped regions. The first dielectric layer is located between the substrate and the upper electrode. The conductive layer is located over the upper electrode, wherein the conductive layer and the upper electrode are isolated from each other and the conductive layer and the doped regions are electrically connected to each other.
