Micromachinned monopole antenna by CMOS-Compatible deep trench technology

A monopole antenna fabricated by standard 0.18 μm CMOS technology is post-IC processed by CMOS compatible inductively coupled plasma etching, which can remove the silicon substrate selectively under the metal strips. After substrate release, the resonance of the monopole antenna reveals owing to elimination of the energy confinement from the high-dielectric media. Experimental results show an improvement of input return loss (S₁₁) from-9 to-14.3 dB by such substrate release technique. The power transfer ratio also increases from 0.87 to 0.96 for better radiation efficiency.