Impact Ionization Noise in SiGe HBTs: Comparison of Device and Compact Modeling With Experimental Results

Noise Parameter Analysis of SiGe HBTs for Different Sizes in the Breakdown Region

“…In [3], the DC measurements are employed to extract the equivalent circuit parameters of their noise model for geometry analysis in the normal operating region. On the other hand, for the breakdown operation, the literatures [9,10] Figure 1: The flowchart of the presented analysis. The cross section of the SiGe HBTs with the diagram for different emitter lengths and emitter widths is also shown.…”

“…For this RF circuit application in the impact ionization region, noise performance of SiGe HBTs needs to be considered because the breakdown mechanism can produce excess noise. In [9,10], noise parameters of SiGe HBTs above BV CEO have been characterized. However, investigation of noise parameters of SiGe HBTs in the breakdown region has not been reported for different sizes.…”

Microwave noise characterisation of AlInAs/GaAsSb/InP DHBTs

“…This noise performance still does not approach the best SiGe HBT results, which show NF min , 1 dB at 10 GHz owing to aggressive device scaling and higher current gains with b 200 [7]. SiGe HBTs however do suffer from a rapid increase of NF min owing to impact ionisation noise as V CE exceeds the BV CEO [7]. In this context, high-speed high-BV CEO GaAsSb DHBTs with AlInAs or InP emitters could become an interesting alternative to SiGe HBTs in higher frequency bands where the reduced BV CEO of high-speed SiGe HBTs is expected to result in excessive noise levels.…”

“…The present devices achieve much improvement over [4] and a similar NF to the smaller and faster InP/ GaAsSb DHBTs of [5] despite the larger emitter widths used here (0.9 compared to a 0.3 mm emitter width in [5]), thanks to the improved current gain achieved with the AlInAs type-I emitter chosen for this Letter. This noise performance still does not approach the best SiGe HBT results, which show NF min , 1 dB at 10 GHz owing to aggressive device scaling and higher current gains with b 200 [7]. SiGe HBTs however do suffer from a rapid increase of NF min owing to impact ionisation noise as V CE exceeds the BV CEO [7].…”

Analytical modelling of 200 GHz SiGe HBT high-frequency noise parameters

“…The simulations include diffusion noise due to particle scattering within the valence or conduction band, and noise due to the Shockley-Read-Hall recombination. These scattering processes are sufficient to describe highfrequency noise, as long as the device is not operated too close to breakdown [25]. The DD model is valid only under quasi-equilibrium conditions, as it utilizes fluctuationdissipation relations to evaluate local microscopic noise sources.…”