  We report the first demonstration of integrated electro-optic (EO) phase
shifters based on racetrack microresonators on a
3C-silicon-carbide-on-insulator (SiCOI) platform working at near-infrared (NIR)
wavelengths. By applying DC voltage in the crystalline axis perpendicular to
the waveguide plane, we have observed optical phase shifts from the racetrack
microresonators whose loaded quality (Q) factors are ~ 30,000. We show voltage
length-product (V${\pi}$${\cdot}$L${\pi}$) of 118 V${\cdot}$cm, which
corresponds to an EO coefficient r$_{41}$ of 2.6 pm/V. The SiCOI platform can
be used to realize tunable SiC integrated photonic devices that are desirable
for applications in nonlinear and quantum photonics over a wide bandwidth that
covers visible and infrared wavelengths.
