  Kerr frequency comb generation relies on dedicated waveguide platforms that
are optimized towards ultralow loss while offering comparatively limited
functionality restricted to passive building blocks. In contrast to that, the
silicon-photonic platform offers a highly developed portfolio of
high-performance devices, but is deemed to be inherently unsuited for Kerr comb
generation at near-infrared (NIR) telecommunication wavelengths due to strong
two-photon absorption (TPA) and subsequent free-carrier absorption (FCA). Here
we present a theoretical investigation that quantifies the impact of TPA and
FCA on Kerr comb formation and that is based on a modified version of the
Lugiato-Lefever equation (LLE). We find that silicon microresonators may be
used for Kerr comb generation in the NIR, provided that the dwell time of the
TPA-generated free-carriers in the waveguide core is reduced by a
reverse-biased p-i-njunction and that the pump parameters are chosen
appropriately. We validate our analytical predictions with time integrations of
the LLE, and we present a specific design of a silicon microresonator that may
even support formation of dissipative Kerr soliton combs.
