| 摘要 |
<p>A doped semiconductor region having a same conductivity type as a bottom semiconductor layer is formed underneath a buried insulator layer in a bottom semiconductor layer of a semiconductor-on-insulator (SOI) substrate. At least one conductive via structure is formed, which extends from a interconnect-level metal line through a middle-of-line (MOL) dielectric layer, a shallow trench isolation structure in a top semiconductor layer, and a buried insulator layer to the doped semiconductor region. The shallow trench isolation structure laterally abuts at least one field effect transistor that functions as a radio frequency (RF) switch. During operation, the doped semiconductor region is biased at a voltage that keeps an induced charge layer within the bottom semiconductor layer in a depletion mode and avoids an accumulation mode. Elimination of electrical charges in an accumulation mode during half of each frequency cycle reduces harmonic generation and signal distortion in the RF switch.</p> |
