Résumé
In addition to the well-known High Frequency noise parameters such as the Noise Factor, the low-frequency noise (LFN) is a critical design constraint. The LFN level is upconverted to the phase noise causing spectral broadening which have a direct impact on the voltage controlled oscillators (VCOs), mixers and amplifiers. Hence, LFN places a fundamental limit on the spectral purity of RF and microwave systems. Moreover, due to its sensibility to defects, traps or generation-recombination centers, LFN is used as a tool to investigate multiple defects in the advanced electronic materials and devices. As a consequence, it can be used to probe some technological steps during the process developments process. For all these reasons, it is necessary to provide a compact model for the LFN excess noise sources (1/f noise component and in a lesser extend generation-recombination noise component). This presentation describes the technique used to measure the low frequency noise for both the input and the output of the bipolar transistors. The Base and the Collector current noise characteristics are investigated along with their compact model in SiGe:C HBTs issued from 0.13 µm and 55 nm BiCMOS technologies. In particular, it presents the modeling of the 1/f noise level versus the Base and the Collector currents (IB, IC) and versus the geometrical parameters. At last, some results concerning the effect of X-ray irradiation and electrical stress are discussed.