Semiconductor integrated circuitry, having a layered structure formed on a substrate, the layered structure comprising a plurality of metal layers and via layers sandwiched between adjacent said metal layers, an upwards direction being defined through the layers away from the substrate, wherein: a capacitor is formed from metal structures implemented in at least first, second and third metal layers which are provided at different positions in the upwards direction, respectively, and ordered in the upwards direction; the metal structures comprise arrangements of strips having widths parallel to the layers, the widths being within one of three ranges of widths, the ranges comprising a lower range of widths, an intermediate range of widths comprising widths larger than those in the lower range of widths, and a higher range of widths comprising widths larger than those in the intermediate range of widths; first strips among the strips are formed in the first layer and are organised into at least one first comb arrangement having a base strip formed in the first layer and a plurality of finger strips formed in the first layer and extending from the base strip, the widths of the finger strips of the first strips and the width of the base strip of the first strips being in the lower range of widths; second strips among the strips are formed in the second layer and are organised into at least one second comb arrangement having a base strip formed in the second layer and a plurality of finger strips formed in the second layer and extending from the base strip, the widths of the finger strips of the second strips being in the lower range of widths, and the width of the base strip of the second strips being in the intermediate range of widths; and the strips formed in the third layer have widths in the higher range of widths. a capacitor is formed from metal structures implemented in at least first, second and third metal layers which are provided at different positions in the upwards direction, respectively, and ordered in the upwards direction; the metal structures comprise arrangements of strips having widths parallel to the layers, the widths being within one of three ranges of widths, the ranges comprising a lower range of widths, an intermediate range of widths comprising widths larger than those in the lower range of widths, and a higher range of widths comprising widths larger than those in the intermediate range of widths; first strips among the strips are formed in the first layer and are organised into at least one first comb arrangement having a base strip formed in the first layer and a plurality of finger strips formed in the first layer and extending from the base strip, the widths of the finger strips of the first strips and the width of the base strip of the first strips being in the lower range of widths; second strips among the strips are formed in the second layer and are organised into at least one second comb arrangement having a base strip formed in the second layer and a plurality of finger strips formed in the second layer and extending from the base strip, the widths of the finger strips of the second strips being in the lower range of widths, and the width of the base strip of the second strips being in the intermediate range of widths; and the strips formed in the third layer have widths in the higher range of widths.