This letter presents a micromachining process to effectively reduce substrate loss via a structure of patterned oxide/nitride fins on a silicon substrate with a resistivity of 1 Ω-cm. Experimental results demonstrate that the insertion loss of a coplanar waveguide (CPW) deposited on the structure can be lowered to the value of 4.33 dB/cm at 40 GHz. Meanwhile, an analytical model is developed to predict the characteristics of the CPW.
- Coplanar waveguide (CPW)
- Effective dielectric constant
- Equivalent impedance
- Oxide/nitride fins
- Radio frequency integrated circuit (RFIC)
- Substrate loss