Juan E. Sanchez

Two-dimensional semiconductor device simulation of trap-assisted generation-recombination noise under periodic large-signal conditions and its use for developing cyclostationary circuit simulation models

The simulation of generation-recombination (GR) noise under periodic large-signal conditions in a partial differential equation-based silicon device simulator is presented. Using the impedance-field method with cyclostationary noise sources, it is possible to simulate the self- and cross-spectral densities between sidebands of a periodic large-signal stimulus. Such information is needed to develop noise correlation matrices for use with a circuit simulator. Examples are provided which demonstrate known results for shot noise in bipolar junction transistors. Additional results demonstrate the upconversion of low-frequency GR noise for microscopically cyclostationary noise sources and provide evidence for applying the modulated stationary noise model for low-frequency noise when there is a nearly quadratic current dependence.

Device simulation of generation-recombination noise under periodic large-signal conditions

The modulation of flicker (1/f or 1/f-like) noise is an important topic for RF communications, as it contributes to the stability of oscillators and the signal-to-noise ratio in mixers. For the first time, simulation results for trap-assisted generation-recombination (GR) noise under large-signal conditions are demonstrated for both a homogeneous resistor and a p/sup +/-n junction in a semiconductor device simulator using the harmonic balance and impedance field methods. It is believed that GR fluctuations are one mechanism which contributes to 1/f-like noise observed in semiconductor devices.

Frequency conversion of flicker noise in bipolar junction transistors

A novel experimental system for the investigation of frequency-translated flicker noise in bipolar junction transistors is demonstrated. First, transistors are characterized for their base-emitter junction behavior and flicker noise parameters in steady state. Then the conversion gain of the baseband flicker noise to the sidebands of the carrier is measured for several different carrier levels upon the application of a large-signal carrier to the transistors under test. The measured conversion gain is compared to that predicted using a harmonic balance noise simulation. Discrepancies between measurement and simulation indicate the presence of an effect not currently addressed in the literature.

Measurements of 1/f noise amplitude modulated by a large-signal carrier in bipolar junction transistors

Abstract A novel experimental system for the investigation of frequency-translated flicker noise in bipolar junction transistors is demonstrated. First, transistors are characterized for their base–emitter junction behavior and flicker noise parameters in steady state. Then, measurements of the frequency conversion of 1/ f noise are performed by the application of a large sinusoidal signal to the base–emitter junctions of bipolar junction transistors. The applied signal is varied in frequency and amplitude, and the resulting conversion gains are reported. A novel measurement technique, which enables the detection of noise fluctuations near a much larger signal is demonstrated. These results are compared with harmonic balance simulation.

A noise simulation post-processor: A new tool for low noise device design

The development of a numerical, postprocessor, device noise simulator, capable of simulating velocity fluctuation and Hooge type 1/f noise is described. Three-dimensional noise maps are presented for a bipolar transistor and MOSFET revealing the noise contributions of specific device areas. Where applicable, good agreement with analytical results is obtained.

Computer simulation and reverse engineering of trap-assisted generation-recombination noise in advanced silicon MOSFETs

Trap assisted generation-recombination noise spectra of advanced n-channel MOSFETs are numerically simulated using the drift-diffusion transport model and focusing on the bimolecular electron transitions between the channel and gate oxide. Good agreement between measured and simulated data is observed in both the linear and saturated regime of operation under sub-threshold and inversion conditions. Reverse engineering of the measured noise data reveals the discrete trap distributions in the oxide responsible for the observed spectra.