Unified Transient and Frequency Domain Noise Simulation for Random Telegraph Noise and Flicker Noise Using a Physics-Based Model

Abstract

Unified transient and frequency domain noise simulation of random telegraph noise and flicker noise is conducted using a multiphonon-assisted model that considers tunneling probabilities and energy transitions of discretized traps in the gate insulator of MOSFETs. The proposed model is able to concurrently represent the dynamic behavior of electron and hole trapping and detrapping via interactions with both the Si substrate and Poly-Si gate. The model is implemented in a 3-D device simulator to examine the effect of device structure and bias conditions. The conventional analytical model does not precisely estimate the noise powers in short-channel MOSFETs due to the nonuniform trapped charge effect. The high trap density near the shallow trap isolation edges is predicted quantitatively by comparing the measured data with the simulated data. In conclusion, we confirm the validity of the developed unified simulator and its usefulness for gaining insights into trap sites and noise reduction engineering.Index Terms-Device simulations, flicker noise, random telegraph noise (RTN), trap distribution.

Comprehensive studies on the accuracy of trap characterization by using advanced random telegraph noise simulator

“…Discretized traps are arranged randomly in the real and energy spaces. [26][27][28] Trapping and de-trapping processes are made to occur by using a Monte Carlo method based on the capture time constant τ c and emission time constant τ e of each trap. We consider energy transitions based on the multiphonon-assisted model.…”

“…We consider energy transitions based on the multiphonon-assisted model. [28][29][30] The model proposed by Herrmann and Schenk 29) reproduces only trapping from the Si substrate and de-trapping to the poly-Si gate in order to calculate the trap-assisted tunneling current. For RTN simulation, we extended the model to reproduce the behavior of de-trapping to the Si substrate and trapping from the poly-Si gate.…”

“…The waveform includes several different trap time constants and amplitude events, and exhibits 1=f-like shape noise in the frequency domain. 28) In the small devices, the mean number of traps is smaller and single trap events therefore occur more frequently. In addition, the mean value of ΔI ds =I ds increases because the number of carriers decreases and the single trap charge effect increases.…”

A physical model of electron trapping/detrapping in electrically stressed oxide

“…We adopt inelastic multi-phonon TAT mechanism [4,10,11,12,13] to model the processes of capture and emission of electrons. Due to the coupling of electron with oxide phonons, a series of virtual trap energy levels are generated in the oxide band gap, thereby enlarges the tunneling probability.…”

“…Therefore, to accurately model the memory cell's endurance and retention characteristics, the filling state of all the bulk traps must be obtained, which requires a comprehensive electron trapping-detrapping (T-D) model. In addition, the electron T-D phenomenon has also great impact on the device's bias temperature instability (BTI) [2,3] and random telegraph noise (RTN) [4,5] as the size scales.…”