Transmission Performances of CPW Lines on a Laser-Crystallization Polysilicon Passivated High-Resistivity Silicon Substrate

In this paper, we report the preparation of polycrystalline silicon by excimer laser-crystallization of amorphous silicon α and its use as a surface-passivation layer (SPL) on high-resistivity silicon (HR-Si) substrates. The transmission loss (α
_TL
) of coplanar waveguide (CPW) lines on an oxide-coated HR-Si substrate with a 100-nm excimer laser-annealed (ELA) SPL is less than 1.16 dB/cm at frequencies up to 20 GHz. Therefore, an ELA-SPL is capable of providing good surface passivation for radio-frequency integrated circuit applications. The influence of geometric parameters on the transmission characteristics of the CPW lines is also studied. Extracted material parameters and equivalent lumped elements are used to interpret the loss mechanisms.