A design for an improved metal-on-metal capacitor design is described. The design includes a substantially diagonal feedline (411, 412, 413) in each metal layer. Each metal layer (21, 22, 23) comprises two sets of metal fingers which are interleaved. Each set of fingers comprises two subsets of fingers and the subsets of fingers are arranged at right angles to each other. Fingers in a first of the two sets are all connected to the diagonal feedline, while fingers in the other set are connected together via fingers at the periphery of the device. The design is repeated in adjacent layers, where the design may be identical or rotated (e.g by 180°) between adjacent metal layers.