The impact of X-ray and cobalt 60 irradiations on the DC characteristics of two advanced BiCMOS technologies, Si/SiGe:C HBTs, is compared and analyzed. The effects of geometry, post-irradiation time, and annealing are investigated.

The DC and low-frequency noise (LFN) study of pre-rad and post-rad X-ray irradiation of SiGe:C HBTs based on a 55 nm BiCMOS technology is presented. HBTs are developed with three different levels of doping in the collector region for applications requiring high speed (HS), medium voltage (MV), and high voltage (HV) operations. This work presents excess DC base current, the 1/f noise model using the SPICE modeling and provides the descriptive behavior of G-R noise components for three different HBTs (HS, MV, and HV) before and after irradiation (as a function of the total ionizing dose (TID)). By comparing the DC and low- frequency noise (LFN) results with respect to TID, the discussion deals with the location of the noise sources and related traps. Particularly, it underlines the role of the SiO2/Si E-B spacer interface.

This work presents Low Frequency Noise (LFNoise) characterization and modeling performed on DPSASEG SiGe HBT integrated in a 55-nm CMOS node. The aim of this study is to evaluate the advantage brought by the implementation of a Dynamic Surface Annealing (DSA) in addition to the well-known Spike Annealing process. The HBTs are supplied by STMicroelectronics Crolles and present transit (fT) and maximum oscillation (fMAX) frequencies in the 320-370 GHz range. Spectra can be affected by the presence of generation-recombination (GR) components. The 1/f noise amplitude is modeled following the SPICE compact model, and the 1/f parameters KF and AF are calculated. The extracted figure of merit KB = KFAe has a very good value of 6.8 10-10 μm² for transistors processed using the DSA technique.

The main objective of the development of new BiCMOS technologies is to enhance the high frequency performances of the devices. Nevertheless, Low Frequency Noise (LFN) analysis, in particular the 1/f noise, is a very sensitive tool to evaluate a technology. In this work we present a complete characterization and modeling of the 1/f noise in Si/SiGe:C HBTs issued from three BiCMOS technologies (130 nm, shrinked 130 nm and 55 nm). The measured base current spectral density SIB, in the HBTs issued from a 130 nm BiCMOS technology, presented a typical behavior of 1/f noise. The extracted SPICE figure of merit Kb has an excellent value of 1.4 10 -10 μm 2 . For HBTs issued from the two other technologies (shrinked 130 nm and recent under development 55 nm) the low frequency noise spectra are often disrupted by the presence of more or less pronounced Lorentzian shape leading to noise dispersion. In HBTs where a typical behavior was observed, the 1/f noise level was found to be proportional to the square of IB, and inversely proportional to the emitter area Ae. The extracted Kb value was equal to 6 10 -10 for the shrinked 130 nm technology and approximately 10 -9 μ 2 for the 55 nm technology. In order to take into account the HF performances, we have also studied the ratio fc/ft. This figure of merit combines LF Noise and HF characteristics.

We study the room-temperature performance of micro-Hall magnetic sensors based on pseudomorphic InGaAs quantum wells. Active areas of our sensors range from 1 to 80 μm. We focus on the smallest detectable magnetic fields in small sensors and perform a systematic study of noise at room temperature in the frequency range between 1 Hz and 100 kHz. Our data are interpreted by the mobility fluctuation model. The Hooge parameter is determined for the applied technology. We show that, independently of the experimental frequency, the ratio of sensitivity to noise is proportional to characteristic length of the sensor. The resolution of 1 mG/Hz is achievable in a 3μm sensor at room temperature.

This work presents an improved measurement setup to directly measure the collector low frequency current spectral density S IC of SiGe:C Heterojunction Bipolar Transistors (HBTs) when the base is AC short-circuited. A comprehensive analysis of the obtained results is also provided as well as a SPICE based electrical model. The additional white noise observed at high collector biases is due to the contribution of the emitter/base internal resistance. The 1/f noise exhibits a linear evolution with a 1.7 slope versus I C and is proportional to 1/√A e . No evolution of S IC with emitter periphery P e was observed. From a comparative study of the different 1/f noise term of S IC we found that S IC is mainly associated with the spontaneous fluctuations of the intrinsic collector current.

This work presents an improved measurement setup to directly measure the collector low frequency current spectral density S IC of SiGe:C Heterojunction Bipolar Transistors (HBTs) when the base is AC short-circuited. A comprehensive analysis of the obtained results is also provided as well as a SPICE based electrical model. The additional white noise observed at high collector biases is due to the contribution of the emitter/base internal resistance. The 1/f noise exhibits a linear evolution with a 1.7 slope versus I C and is proportional to 1/√A e . No evolution of S IC with emitter periphery P e was observed. From a comparative study of the different 1/f noise term of S IC we found that S IC is mainly associated with the spontaneous fluctuations of the intrinsic collector current.

In this work, we present LFNoise measurements versus temperature (120 K-295 K) in SiGe:C HBTs issued from a 0.13 μm BiCMOS technology supplied by STMicroelectronics. For this temperature range (120 K-295 K) on TO box mounted transistors are used. The base current spectral density, S IB , is directly measured using a low noise current amplifier base setup measurement. All the tested transistors showed steady 1/f noise level for temperatures higher than 160 K. Below 220-240 K, generation-recombination (g-r) components appeared and increased more and more with the decrease of the temperature. Concerning the g-r components, two behaviors were observed at very low temperature. It must be noticed that, for the tested transistors, no RTS signature was observed in the time domain, except at very low temperature where a very small RTS amplitude was observed for a few transistors.

This work presents an investigation of DC and Low Frequency Noise dispersion in 0.13μm SiGe:C BiCMOS Heterojunction Bipolar Transistors (HBTs) used for mm-Wave to Terahertz applications. Therefore, DC and Low Frequency Noise measurements have been performed over a half wafer on a large number of transistors. A statistical 1/f noise compact model is presented as well as a study of the repartition of generation-recombination components. The main Low Frequency Noise sources are found to be homogenously distributed in the intrinsic base-emitter junction. The mean 1/f noise level, evaluated by the figure of merit KBmean, is equal to 6 10−10μm2.

In this study, we present recent low frequency noise results obtained on Si/SiGeC Heterojunction Bipolar Transistors (HBTs) associated with a 0.13μm BiCMOS technology. Two technologies are studied, referenced as A and B, with high frequency figures of merit f T /f MAX (unity current gain frequency/maximum oscillation frequency) 220/280 GHz for technology A and 300/400 GHz for technology B. The LF Noise measurements are performed in the 1Hz-100 kHz frequency range as a function of the base bias current and of the emitter area A E . The 1/f noise component is studied through the SPICE LFN parameters A F and K F . The K B figure of merit (K B = K F *A E ), used to compare the 1/f noise level, has an excellent value of 1.5 10 -10 μm 2 for technology A and above 6 10 -10 μm 2 for technology B. Dispersion of the 1/f noise level observed on technology B is associated to the presence of predominant GR components. A temperature study of the 1/f noise level evolution in the range 15-100°C was also done. The temperature dependence is week except at very low base current bias.

A numerical model for inhomogeneous devices simulation as 2D-carbon nanotubes thin films is presented. This model takes into account nonlinear effects, in this work the proposed approach is based on tube-tube junctions which are presented as nonlinear dipoles depending on the nature of each junction (M/M), (SC/SC) and (M SC). Modified Nodal Analysis “MNA” and the adjoint network method are respectively used to simulate the current and the 1/f noise. This type of simulation allows understanding and analyzing of unexpected experimental results. In this paper simulation point-out the impact of nanotubes' clusters on the 1/f noise behavior of the NT films.

We present an experimental study on the performance of nano-Hall sensors made on the two dimensional electron gaz of a pseudo morphic GaAlAs/GaInAs heterostructures. The active area of the sensor is from sub-micronic scale (down to 500 nm) to 5 microns. Ohmic contacts have micronic size, and a reference sample of 80 micron width has been caracterized as well, as a reference. In our process, we have improved the contacts technology to limit the thermal Shottky noise. Thus although ohmic contacts have small dimensions they have low resistance and do not limit the sensitivity of our nano-sensors. Extensive caracterization of those devices demonstrate a diffusive transport at 300 K, and a magnetic field sensitivity up to 1000 V/T/A. We have focused our attention on the smallest detectable magnetic field in the smallest sensor, and performed a systematic study of the noise measurements. We have measured the excess noise in both the longitudinal configuration and the Hall configuration, as a function of the current. Our noise measurements performed at room temperature in the range [1 Hz-100 kHz] show, at low frequency, an 1/f noise spectrum whose intensity is proportional to the square of the current. We understand our data by the conductivity fluctuations model and we obtain the Hooge parameter for this technology. We demonstrate that the noise intensity is inversely proportional to area of the sensor. Of course reducing the dimensions induces physical limitations but we demonstrate that a magnetic field of few μT can be measured with a micron scale sensor at low frequencies; at higher frequencies, when the thermal noise limits the resolution, the measurement of 300 nT is achievable.

In this study, we present recent low frequency noise results obtained on Si/SiGe:C Heterojunction Bipolar Transistors (HBTs) associated with a 0.13 μm BiCMOS technology. The HBTs are supplied by STMicroelectronics Crolles and present unity current gain frequencies (fT) and maximum oscillation frequencies (fmax) in the 250s of GHz. The 1/f noise sources are found to be located in the intrinsic emitter-base (E-B) region. The 1/f noise figure of merit, KB, is found to be close to 1.5 10-10 μm2. This excellent result is at least one decade better than the initial development of this 0.13 μm BiCMOS technology. Moreover, in order to take into account the improvement of the high frequency parameters (fT and fmax) associated to this technological evolution, we have studied the ratio fC/fT, figure of merit that links LF Noise and transistor speed. We have analyzed the 1/f noise improvement from different technological aspects related to the emitter-base process, for instance the surface cleaning (prior to the polysilicon deposition) and the epitaxial regrowth of the polysilicon.

In this study, we present recent low frequency noise results obtained on Si/SiGe:C Heterojunction Bipolar Transistors (HBTs) associated with a 0.13 µm BiCMOS technology. The HBTs are supplied by STMicroelectronics Crolles and present unity current gain frequencies (f T ) and maximum oscillation frequencies (f max ) in the 250s of GHz.

In this study, we present recent low frequency noise results obtained on Si/SiGe:C Heterojunction Bipolar Transistors (HBTs) associated with a 0.13 mu m BiCMOS technology. The HBTs are supplied by STMicroelectronics Crolles and present unity current gain frequencies (f(T)) and maximum oscillation frequencies (f(max)) in the 250s of GHz.The 1/f noise sources are found to be located in the intrinsic emitter-base (E-B) region. The 1/f noise figure of merit, K-B, is found to be close to 1.5 10(-10) mu m(2). This excellent result is at least one decade better than the initial development of this 0.13 mu m BiCMOS technology. Moreover, in order to take into account the improvement of the high frequency parameters (f(T) and f(max)) associated to this technological evolution, we have studied the ratio f(c)/f(T), figure of merit that links LF Noise and transistor speed.We have analyzed the 1/f noise improvement from different technological aspects related to the emitter-base process, for instance the surface cleaning (prior to the polysilicon deposition) and the epitaxial regrowth of the polysilicon.

In this paper, we present a study of 2-D Carbon Nanotubes “CNTs” thin film. Transport and noise fluctuation of two types of films are measured and compared. We have developed a theoretical model based on CNT physics, where the films are described as an electrical network. Simulations using a Modified Nodal Analysis “MNA” provide DC and noise characteristics comparable to the experimental results.

In this work, the authors demonstrate that the meta-stable DRAM (MSDRAM) can achieve better performances regarding to the sensing margin compared to programming methods like impact ionization and forward biased junctions. This improvement results mainly from the low current level at 0-state. Indeed, the MSDRAM uses gate capacitive coupling method which allows to reach zero current level. Finally, the band-to-band tunneling used to program the 1-state strongly reduces the power consumption and improves the device reliability. These promising results promote the meta-stable dip (MSD) programming mechanism as a viable solution for low power single-transistor DRAM memories.

The aim of this work is to study the behavior of a VDMOSFETs N-channel transistor pre-exposed to electrical stress where experimental results show a consistent degradation in the devices characteristics. The resultant aging in the studied devices have been attributed to trapped holes, trapped electrons and interface states. The electrical stress was applied using the two well-known techniques, widely used in the literature: CVS (Constant Voltage Stress) and hot-carriers injection stress. Degradations coming from the electrical stress were followed by a measurement for the gate to source capacitance, the threshold voltage and the Flat Band voltage before and after each stress dose.

In this paper we present a simulator for electrical properties of carbon nanotube film field-effect transistors. The simulator, based on carbon nanotube physics uses Landauer formalism and Poisson equation. The total film is described as an electrical network. A modified nodal analysis provides DC and noise characteristics. These simulations are in good agreement with experimental results.