Temperature and Substrate Effects in Monolithic RF Inductors on Silicon With 6- -Thick Top Metal for RFIC Applications

Comprehensive analyses of the effects of temperature (from -50degC to 200 degC), silicon substrate thickness, and proton implantation postprocess on the performances of a set of planar spiral inductors with 6-mum-thick top metal are demonstrated. Quality-factor (Q-factor) and power gain (G_A) decrease with increasing temperatures but show a reverse behavior within a higher frequency range. Stability-factor (K-factor) and noise figure (NF) increase with increasing temperatures but show a reverse behavior within a higher frequency range. The reverse frequencies f_R, which correspond to the zero temperature coefficient of G_A, K-factor, and NF, are almost the same. In addition, both the silicon substrate thinning and proton implantation are verified to be effective in improving the Q-factor and NF performances of inductors on silicon. The present analyses enable RF engineers to understand more deeply the Q-factor and NF behavior of inductors fabricated on a thin silicon substrate (20 mum) and hence are helpful for them to design high-performance fully on-chip low-noise-amplifiers and other RF integrated circuits