  Several future high-energy physics facilities are currently being planned.
The proposed projects include high energy $e^+ e^-$ circular and linear
colliders, hadron colliders and muon colliders, while the Electron-Ion Collider
(EIC) has already been approved for construction at the Brookhaven National
Laboratory. Each proposal has its own advantages and disadvantages in term of
readiness, cost, schedule and physics reach, and each proposal requires the
design and production of specific new detectors. This paper first presents the
performances required to the future silicon tracking systems at the various new
facilities, and then it illustrates a few possibilities for the realization of
such silicon trackers. The challenges posed by the future facilities require a
new family of silicon detectors, where features such as impact ionization,
radiation damage saturation, charge sharing, and analog readout are exploited
to meet these new demands.
