Structured interfaces with subwavelength features enable modulations of phase, amplitude, and polarization on demand, leading to a plethora of flat-profile devices and metasurfaces. Plasmonic and dielectric metasurfaces have been intensively explored, building up the frameworks of flat optics for ultrathin and integrated nanophotonics. The in situ controllability and tunability of aforementioned family of metasurfaces, however, has been a grand challenge, due to the intrinsic limitations of the materials. Semiconductors with diversified catalogs of material candidates thus demonstrate promising potentials, owing to the mature and versatile technologies developed nowadays. The fuse of semiconductors and nanostructured metasurfaces has been witnessed more recently, paving a distinct avenue toward active, tunable, reconfigurable light manipulation for next-generation optical nanodevices. Judicious selection of the active materials for metasurfaces empowers the active functionality of the designer applications. This paper presents a review of this merging semiconductor paradigm for active metasurfaces across a wide range of spectrum and shows unprecedented potentials in the future interface-based optoelectronics, quantum optics, nano-optics, and surface engineering with full compatibility of semiconductor foundry.