Random Telegraph Noise Analysis Research Articles

Bias dependence in statistical random telegraph noise analysis based on nanoscale CMOS ring oscillators

Random Telegraph Noise (RTN) is one of the major reliability concerns in nanoscale complementary metal-oxide semiconductor (CMOS) technologies. In this paper, we discuss the characterization of RTN in 40 nm CMOS technology using Ring Oscillators (ROSCs). We used different types of ROSCs to study the temporal and spectral characteristics of the RTN. We conducted measurements on one of the arrays with 128 identical ROSC cells. These results enabled statistical characterization of the RTN amplitude strength and its frequency characteristics in different supply voltage variations from 0.5 V to 0.7 V. At power supply of 0.65 V, dominant and observable RTN amplitude above 0.37% Δf/fmean\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Delta f/f_{\ ext{mean}}$$\\end{document} is found in 60% of cells in the array. Further, the capture and emission time constant τe//c\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\ au_{e//c}$$\\end{document} can be extracted from the measurements, the values observed ranging from 0.2 μ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\upmu$$\\end{document}s to 10 ms.

Universality of trap-induced mobility fluctuations between 1/f noise and random telegraph noise in nanoscale FD-SOI MOSFETs

Low frequency noise (LFN) and random telegraph noise (RTN) are investigated statistically on nanoscale MOSFETs of 28 nm fully depleted silicon-on-insulator technology. The analysis reveals that the mean noise level is well described by the carrier number fluctuations with a correlated mobility fluctuations model. As for the RTN, it is shown that the mean amplitude of signals is driven by correlated mobility fluctuations in strong inversion. The comparison between the extracted parameters of the LFN and RTN analysis demonstrates that the remote Coulomb scattering impact due to the trapped and detrapped charges remains the same on average for this technology, whether it is the average noise spectrum of all devices or the average amplitude of the detected RTN signals.

Multi-level resistance switching and random telegraph noise analysis of nitride based memristors

Resistance switching devices are of special importance because of their application in resistive memories (RRAM) which are promising candidates for replacing current nonvolatile memories and realize storage class memories. These devices exhibit usually memristive properties with many discrete resistance levels and implement artificial synapses. The last years, researchers have demonstrated memristive chips as accelerators in computing, following new in-memory and neuromorphic computational approaches. Many different metal oxides have been used as resistance switching materials in MIM or MIS structures. Understanding of the mechanism and the dynamics of resistance switching is very critical for the modeling and use of memristors in different applications. Here, we demonstrate the bipolar resistance switching of silicon nitride thin films using heavily doped Si and Cu as bottom and top-electrodes, respectively. Analysis of the current-voltage characteristics reveal that under space-charge limited conditions and appropriate current compliance setting, multi-level resistance operation can be achieved. Furthermore, a flexible tuning protocol for multi-level resistance switching was developed applying appropriate SET/RESET pulse sequences. Retention and random telegraph noise measurements performed at different resistance levels. The present results reveal the attractive properties of the examined devices.

Reduction of random telegraph noise by high-pressure deuterium annealing for p-type omega-gate nanowire FET

In this work, we studied the effect of high-pressure deuterium annealing (HPDA) on a p-type omega-gate nanowire field effect transistor by random telegraph noise (RTN) signal analysis. After HPDA under conditions of 400 °C and 10 atm for 30 min, IOFF decreases by 41.2% and ION increases by up to 5.4%. Also, subthreshold swing (SS) is reduced from 72 mV dec−1 to 70 mV dec−1. In RTN analysis, multi-level RTN is reduced to single-level RTN due to the passivation of a fast trap site by HPDA. ΔID/ID is also decreased 1.3 and 1.1 times at |VOV| = 0.2 V and 0.4 V, respectively. From the low-frequency noise analysis, the reduction of trap density is observed by 86% at |VOV| = 0.4 V after HPDA. Through these results, we found that the HPDA reduces traps of gate dielectric and improves the quality of the interface between gate dielectric and NW channel in p-type OGNW FET.

Statistical Analysis of the Random Telegraph Noise in a 1.1 μm Pixel, 8.3 MP CMOS Image Sensor Using On-Chip Time Constant Extraction Method.

A study of the random telegraph noise (RTN) of a 1.1 μm pitch, 8.3 Mpixel CMOS image sensor (CIS) fabricated in a 45 nm backside-illumination (BSI) technology is presented in this paper. A noise decomposition scheme is used to pinpoint the noise source. The long tail of the random noise (RN) distribution is directly linked to the RTN from the pixel source follower (SF). The full 8.3 Mpixels are classified into four categories according to the observed RTN histogram peaks. A theoretical formula describing the RTN as a function of the time difference between the two phases of the correlated double sampling (CDS) is derived and validated by measured data. An on-chip time constant extraction method is developed and applied to the RTN analysis. The effects of readout circuit bandwidth on the settling ratios of the RTN histograms are investigated and successfully accounted for in a simulation using a RTN behavior model.

Guidelines for a Reliable Analysis of Random Telegraph Noise in Electronic Devices

In this paper, we propose new guidelines for the analysis of random telegraph noise (RTN) in electronic devices. Starting from an in-depth understanding of RTN signal characteristics, we will identify the correct measurement conditions to enable RTN analysis as a characterization tool for electronic devices. The estimate of RTN statistical parameters may indeed strongly depend on the choice of measurement conditions. We will carefully consider both the measurement limits and the extraction process constraints to devise a strategy to identify RTN signals measured in conditions allowing a meaningful estimation of their parameters. The proposed strategy will be tested on a variety of different RTN signals and operating conditions.

A study on HfO2 RRAM in HRS based on I–V and RTN analysis

This paper presents a statistical characterization of random telegraph noise (RTN) in hafnium-oxide-based resistive random access memories (RRAMs) in high resistive state (HRS). Complex RTN signals are analyzed exploiting a Factorial Hidden Markov Model (FHMM) approach, which allows to derive the statistical properties of the RTN signals, directly related to the physical properties of the traps responsible for the multi-level RTN measured in these devices. Noise characteristics in different reset conditions are explored through consecutive switching cycles. Noise spectral analysis is also performed to fully support the investigation. An RRAM compact model is also exploited to estimate the physical properties of the conductive filament and of the dielectric barrier from simple I–V data. These tools are combined together to prove the existence of a direct statistical relation between the reset conditions, the volume of the dielectric barrier created during the reset operation and the average number of active traps contributing to the RTN.

Random telegraph noise analysis in AlOx/WOy resistive switching memories

In this Letter, the origins of current fluctuations of Al/AlOx/WOy/W bilayer resistive random access memory (RRAM) devices are investigated through detailed noise analysis. Random telegraph noise (RTN) measurements were performed on RRAMs with three different resistance states. An obvious RTN signal with 40.7% amplitude difference was found at high resistance state, and the trapping/de-trapping process leading to the RTN signal was studied in detail by extracting the trap energy from energy diagram. For median and low resistance states, the resistance fluctuations were 34.0% and 0.3%, respectively. To further study the RTN characteristics, the normalized power spectral density (PSD) was analyzed. It is found that, for one dominant-trap caused RTN phenomena, the normalized noise PSD behaves as 1/f 2 on the high resistance state; while for median and low resistance states, the noise follows 1/f rule, suggesting that the current fluctuations are associated with the envelop of multiple RTNs caused by traps located near/in the conductive filament. Based on the noise analyses in time and frequency domains, a conduction mechanism is proposed to describe the trap effects on the current fluctuations of different resistance states.

Analysis and modeling for random telegraph noise of GIDL current in saddle MOSFET for DRAM application

The characteristics of the Random Telegraph Noise (RTN) in Gate-Induced Drain Leakage (GIDL) current are first investigated. Based on the Hurkx model, a new model is developed for the Trap-Assisted-Tunneling (TAT) and Band-to-Band Tunneling (BBT) regimes in Saddle Metal-Oxide-Semiconductor Field-Effect Transistor (Saddle MOSFET) for DRAM applications. The three-dimensional Technology-based Computer Aided Design (TCAD) simulator is used to quantitatively analyze and model the RTN. The RTN amplitude in GIDL current (i.e., ΔI/I) increases with increasing drain-to-gate voltage (VDG) in the TAT regime, whereas ΔI/I decreases with increasing VDG in the BBT regime. Simulation results are well matched to the results estimated by the newly-proposed equations derived from the Hurkx model. This model would open a new pathway for the RTN analysis in DRAM devices.

Correlation Between Random Telegraph Noise and $ \hbox{1}/f$ Noise Parameters in 28-nm pMOSFETs With Tip-Shaped SiGe Source/Drain

The random telegraph noise (RTN) characteristics of 28-nm pMOSFETs with tip-shaped SiGe source/drain have been investigated. RTN analysis found that strained devices undergo higher compressive strain; the trap position from the Si/SiO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> interface is reduced, because of the closer trap energy level near the valence band. Although tip-shaped SiGe process induces higher oxide trap density, the trap position corresponding to the tunneling attenuation length (λ) may result in lower 1/ <i xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">f</i> noise level in tip-shaped SiGe S/D devices as compared with that of control devices.

Time-dependent defect spectroscopy for characterization of border traps in metal-oxide-semiconductor transistors

We introduce the time-dependent defect spectroscopy (TDDS) for the analysis of a particular class of oxide defects known as ``border traps.'' These defects have a fundamental impact on the behavior of metal-oxide-semiconductor field-effect transistors and are commonly linked to the occurrence of random-telegraph noise, $1/f$ noise, and slow charging transients. The TDDS naturally extends the successful deep-level transient spectroscopy as it extracts both the capture and emission time constants. Analysis proceeds via the so-called spectral maps, which separate individual border traps by their characteristic times and their voltage step height. In contrast to standard random-telegraph noise analysis methods, where uncorrelated capture and emission events of only a few traps can already create convoluted noise patterns, the synchronization by the charging pulse yields the spectral maps, which allow for the analysis of a large number of defect occupancies in a single measurement. As a consequence, the TDDS allows us to monitor the defect parameters over exceptionally wide temperature and bias ranges.

Random telegraph noise analysis in time domain

A new procedure for analysis of random telegraph signals in time domain has been developed and applied to the analysis of voltage fluctuations in the current induced dissipative state in superconducting thin films. The procedure, based entirely on the difference in the statistical properties of discrete Marcovian telegraph fluctuations and Gaussian background noise, ascribes each point of the experimental time record to one of the telegraph states. The average statistical lifetimes and amplitudes of the telegraph signal are then determined in an iterative way by fitting the amplitude histogram of thus obtained record of the redistributed data to the two-Gaussian histogram of the original experimental signal. The procedure allows for analyzing “noisy” random telegraph signals with low ratio between the signal amplitude and the intensity of the background noise that cannot be analyzed by the classical approach. Separation of the time record into two subrecords relative to two telegraph states also enables in-depth analysis of the spectral properties of the background noise observed together with the telegraph fluctuations.