Behavior of Gold-Doped Silicon Substrate under Small- and Large-RF Signal

In this paper, small- and large-signal performances of passive devices integrated on high-resistivity, trap-rich and gold-doped silicon wafers are presented and compared through measurements and simulations. We show that the gold-doped substrate presents high effective resistivity and low losses suitable for RF applications. Large-signal measurements of gold-doped substrates show 44 dBm lower harmonic distortion than high-resistivity substrates. A large DC bias dependence on the harmonic distortion induced by the gold-doped substrate is observed. This unexpected behavior is explained using the Fermi level localization in the silicon bandgap for the different DC bias conditions.