High-density metal-oxide semiconductor (MOS) capacitor (MOSCAP) cell circuits and MOS device array circuits are disclosed. A gate comprising a selected aspect ratio disposed in a MOSCAP cell circuit comprising a cell region is configured to increase a capacitive density by increasing an extent to which metal routing layers contribute to a total MOSCAP cell circuit capacitance. An area of a MOSCAP array circuit is also reduced. Also, bulk tie cells are disposed within a MOS device array circuit in array diffusion regions to increased MOS device array circuit density. The array diffusion regions include a first device region including MOS devices and a bulk tie region including the bulk tie cells. The bulk tie region is isolated from the first device region by a diffusion cut. A diffusion cut is between a first gate on the device region and a second gate on the bulk tie region.