Precision measurement of pixel sensor capacitance

The capacitance of the charge collection node a sensor system is an important parameter for design analog front-end electronics. high-granularity sensors like example hybrid pixel detectors need to be optimized timing resolution, power consumption, and electronics noise - parameters which all depend on capacitance. Current detector developments HL-LHC upgrade typically use silicon with size in order $50 \times 50 um^2$ have several tens fF, depending geometry. We developed dedicated integrated circuit bump-bonded sensor, enables precise measurement by using charge-based method. In this paper, we will describe method implementation chip (Pixcap65) show results planar whose influenced variations implant