Study of MOSFET Low Frequency Noise Source Fluctuation Using a New Fully Programmable Test Set-up

The measurement of low frequency noise can be considered as an important part in optimization of sensor noise-signal ratio. But sometimes, the intrinsic low frequency noise is affected by contact noise, which can be generated by geometrical defect of thin film. Thus, the measured noise level could not reveal material properties. We report different low frequency noise measurement methods in a general geometry sample of thin film. A detailed analysis of noise measurement has been described by relative equations. Finally, a discussion has been investigated in systematic measurements of low frequency noise at room temperature in La <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.7</sub> Sr <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.3</sub> MnO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> (LSMO) thin films and noise measurements are presented by noise spectral densities as function of frequency.

Defect spectroscopy using 1/ fγ noise of gate leakage current in ultrathin oxide MOSFETs

Influence of gate leakage current on AlGaN/GaN HEMTs evidenced by low frequency noise and pulsed electrical measurements

In organic thin-film transistors (OTFTs) the intrinsic properties of the semiconductor are generally masked by structural defects which localize and trap the charge carriers and contact effects, which limit charge injection and cause deviation from ideal linear and square-law behavior. Thus, their electrical characteristics are strongly dependent on the fabrication conditions. We perform current-voltage (I-V) and low frequency noise (1/f) measurements to demonstrate a direct correlation between the thin film microstructure and the performance of OTFTs. Using fluorinated 5,ll-bis(triethylsilylethynyl) anthradithiophene as a model system, we show the relevance of the grain size and grain distribution in the changes in the electronic properties in an OTFT. We present a simple method to induce enhanced grain growth in solution-processed TFTs by room-temperature chemical modification of the source-drain contacts. This leads to improved device performance, and gives an unique thin film microstructure for fundamental studies concerning the effect of structural order on the charge transport. We present evidence that the 1/f flicker noise is sensitive to the microstructure of the organic semiconductor thin film in the transistor channel and can be a diagnostic tool for the quality of the devices.

Robust, versatile, direct low-frequency noise characterization method for material/process quality control using cross-shaped 4-terminal devices

The development of fiber optic interferometric sensor systems has created new demands for single mode semiconductor diode lasers with low output noise power. Recently, several single longitudinal and transverse mode GaAlAs laser diodes have become available. Several experimenters have reported the deleterious effects of optical feedback resulting from fiber optic coupling on the laser's mode structure and high frequency noise spectrum.1-3 Our interest for interferometric sensors is in the low frequency noise, up to a few kilohertz. We report here the first such low frequency noise measurements in fiber coupled and uncoupled single mode diode lasers. Additionally, we also show that the use of index matching fluid can be used to greatly reduce optical feedback and its associated low frequency noise, upon coupling into an optical fiber.

In this study, we demonstrate the capability to detect microscopic stable displacement nature created by proton irradiations with a method based on the discrimination of the three major low frequency noise sources generally observed in semiconductor devices. Low frequency noise measurements are carried out in silicon in-situ phosphorus doped polycrystalline silicon serpentine resistance used as test vehicle. We observe that for the pristine sample, the voltage noise power density can be explained only considering 1/f and thermal noise contribution on the total noise, while for irradiated sample generation recombination noise prevails. Preliminary results on low frequency noise spectroscopy, used as a diagnostic tool in order to identify stable traps created by protons irradiations are presented.

Low frequency noise in short-channel MOSFET's degraded by Fowler-Nordheim and Hot-Carrier Injection

Silicon founders give in their MOS transistor card models some low-frequency noise parameters for SPICE-based circuit simulators corresponding to pure 1/f a or flicker noise, with a very close to unity. MOS transistors used in analogue circuit applications are usually devices with large channel length and width. In low-noise applications, methods such as correlated double sampling are used to suppress the low frequency noise generated by them. Nevertheless, the transistors presently are submicrometre devices exhibiting very different low-frequency noise behaviour. In this paper, experimental low-frequency noise results obtained at room temperature on NMOS and PMOS transistors fabricated using a 0.7 μm process are presented. Both large and small devices on the same process are considered. All regions of operation of transistors are considered. We show that the low-frequency noise behaviour of small area MOSFETs is very different from that of large area devices and that the spectrum is the summation of Lorentzian spectra generated by the switching of individual active traps.

In this work we show the results of low frequency noise measurements (LFNMs) in staggered bottom gate top contact organic thin film transistors (OTFTs) made with dinaphtho-[2,3-b: <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$2^{\prime} $ </tex-math></inline-formula> , <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$3^{\prime} $ </tex-math></inline-formula> -f]thieno[3,2-b]thiophene (DNTT) as semiconductor layer and CYTOP <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {TM}}$ </tex-math></inline-formula> as dielectric layer. The measured 1/f noise follows a correlated number-mobility fluctuation mechanism with an extracted trap density <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$ &lt; {10}^{{10}}$ </tex-math></inline-formula> cm <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{{-{2}}}$ </tex-math></inline-formula> eV <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{1}}$ </tex-math></inline-formula> , the lower value ever reported for OTFTs and comparable to c-Si devices. On the other hand, the extracted Coulomb scattering parameter is in the order of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$10^{{7}}$ </tex-math></inline-formula> Vs/C, in line with previous measurements on organic transistors. In particular we found similar results from device batches with technological differences and a much lower noise from reference devices with SiO2 dielectric, suggesting that the low noise and extracted trap density can be mainly attributed to the quality of the DNTT/Cytop <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{\text {TM}}$ </tex-math></inline-formula> interface.

Low-frequency (flicker) noise is one of the most important issues in the design of direct-conversion zero-IF front-ends. Within the front-end building blocks, the direct-conversion mixer is critical in terms of flicker noise, since it performs the signal down-conversion to baseband. This paper analyzes the main sources of low-frequency noise in Gilbert-cell-based direct-conversion mixers, and several issues for minimizing the flicker noise while keeping a good mixer performance in terms of gain, noise figure and power consumption are introduced in a quantitative manner. In order to verify these issues, a CMOS Gilbert-cell-based zero-IF mixer has been fabricated and measured. A flicker noise as low as 10.4 dB is achieved (NF at 10 kHz) with a power consumption of only 2 mA from a 2.7 V power supply. More than 14.6 dB conversion gain and noise figure lower than 9 dB (DSB) are obtained from DC to 2.5 GHz with an LO power of -10 dBm, which makes this mixer suitable for a multi-standard low-power zero-IF front-end. Copyright © 2008 John Wiley & Sons, Ltd.

In this paper the theoretical analysis of Low-frequency (LF) noise sources in Optoelectronic Coupled Devices (OCDs) is given and the relation between typical defects and LF noise (1/f noise, generationrecombination (g-r) nosie and burst noise) is described. According to LF noise sources of OCDs and device reliability estimation methods, a novel measurement system based on virtual instrument for OCDs is introduced and nV-level measurement precision can be achieved with the typical LF noise measurement system, which can be used to screen potential devices with excess noise and assess device relibility classifications. In this experiment, the top and bottom limitative thresholds were used to estimate the components parameters of the Power Spectrum Density (PSD) for estimating the reliability of OCDs by the average noise PSD for the 200 OCDs and the classification criterions of electronic components. The experimental results demonstrated that high reliability requirements can be satisfied.

The experiences of stress are common to all living things. Noise is one of the most widespread sources of environmental stress. Noise is a pervasive aspect of many modern community and work environments. So, it is important to consider noise when we design human-oriented products. This study investigates the responses of electrocardiogram (ECG) and eye tracker data in order to evaluate the direct effects of low, middle, and high frequency noise on the two main physiological stress axes: the autonomic nervous system, and cognitive responses for a human-oriented product design. A subject was exposed to low (100 Hz), middle (1000 Hz), and high frequency (100000 Hz) noise while awake. ECG and eye tracker data were collected during noise exposure. Sympathetic nervous system (SNS) activity was less in the low and high frequency noise ranges compared to the no sound. On the other hand, parasympathetic nervous system (PNS) activity was greater in the low and high frequency noise ranges than the SNS activity in the no sound. The cognitive responses or latency saccadic eye movement (LSEM), in low or high frequency noise was greater than that in the no sound. And results of EEG and eye movement were statistically significant in low and high frequency noise (r > 0.93, p < 0.05). The findings of this study indicate that the stress induced by low frequency noise is as stressful as the stress induced by high frequency noise. Additionally, utilizing eye tracker data and acquiring the LSEM is useful in the analysis of human stress responses during various stressful situations in addition to the analysis of human stress responses during noise exposure.

The qualification of a technology needs rigorous and numerous stress experiments to attest of a high level of reliability. Low frequency noise measurements are known as an effective characterization method for the evaluation of device reliability. This technique is usually applied on the drain current spectral density, but it is now largely accepted that the gate access is a major reliability indicator. Moreover, devices featuring slight differences in their drain current noise can be subjected to strong differences on their gate leakage currents, and as a consequence on the current low frequency noise (LFN). In the present work, LFN measurements are investigated on the gate and drain currents of two sets of AlGaN/GaN high electron mobility transistors (HEMTs) with high and low gate leakage currents. It is demonstrated that devices featuring weak differences on their drain current can be subjected to strong differences on their gate leakage signatures: moreover, it is found that the high leakage current can generate numerous traps under the gated zone of the transistor, leading to a change of the intrinsic tuning voltage and by consequence of the number of carriers, thus explaining the reduction on the drain current. The transistors show a difference of 3 to 4 decades on their gate current noise and a negligible shift of 20% on their drain current noise. The large variations on the gate LFN signatures between the two sets of devices, and the induced charges for the leaky devices can probably be related with large differences on the expected lifetimes for the devices under test.

Interface state densities, low frequency noise and electron mobility in surface channel In 0.53Ga 0.47As n-MOSFETs with a ZrO 2 gate dielectric