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

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.

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.

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

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.

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

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

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.

Wide band-gap oxide nanowires, such as ZnO, SnO 2 and In 2 O 3 , are attractive candidate for next-generation nano-electronics, because of their high mobilities and compatibility with low temperature processes. They could provide the drive electronics for future transparent/flexible displays, based on their optical transparency and mechanical flexibility. Nanosecond-pulse excimer laser annealing of nanowires, a promising annealing method compatible with glass and plastic substrates, has been reported to improve performance of both nanowire resistors and field effect transistors [1]. However, in order to move toward future commercial nano-electronics, it is still necessary to improve and stabilize the transistor characteristics of nanowire devices and to understand the mechanisms responsible for the current-voltage relationships. We report the effects of annealing of the metal contacts to the nanowires using femtosecond laser pulses focused on the contact regions. The annealing induces significant shifts in the threshold voltage, and significantly reduces the drain conductance (g ds ) of the nanowire transistors in the saturation region, along with modest improvements in the subthreshold slopes. Low frequency (1/f) noise measurements in these devices reveal that Hooge's constant is reduced following laser annealing presumably due to improved channel-metal interface and lowered Schottky barrier height.

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.

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.

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

The paper covers the methods of measurement of noise from building equipment included in the drafts of the new European standards: pr EN ISO 10052 – survey method and pr EN ISO 16032 – engineering method. The results of acoustic surveys performed in several apartments are the basis for discussing the problems of measurement and evaluation of low frequency noise, in the light of the binding and the proposed measuring methods. The proposed assessment method for the noise spectrum is given.

Although In2O3 nanofibers (NFs) are regarded as one of the active channel materials for next‐generation, low‐cost thin‐film transistors (TFTs), these NFs‐based devices still suffer from the degraded carrier mobility and operational instability, limiting the ability of such devices to replace current polycrystalline silicon technologies. Here, it is shown that nanofiber channel transistors with high electron mobility and operational stability can be achieved by selectively doping Zn element into electrospun In2O3 NFs. By precisely manipulating the doping level during NFs fabrication, their crystallinity, surface morphology, and corresponding device performance can be regulated reliably for enhanced transistor performances. It has been detected that InZnO/SiO2 TFTs with an optimized Zn doping concentration of 50% have demonstrated the high field‐effect mobility (µFE) of 6.38 cm2 V−1 s−1, the larger ION/IOFF of 4.12 × 107 and operation in the energy‐efficient enhancement‐mode. Low frequency noise (LFN) measurements have displayed that the scattering and defects inside the NFs are effectively suppressed by the particular microstructure. When integrating ALD‐derived Al2O3 films as the gate dielectric into TFTs devices, their electron mobility and ION/IOFF can be further improved to 37.82 cm2 V−1 s−1 and 2.92 × 108, respectively. To demonstrate the potential toward more complex logic applications, a low voltage resistor‐loaded unipolar inverter is built by using InZnO/Al2O3 TFT, exhibiting a high gain of 20.95 and full swing characteristics. These optimized parameters have demonstrated the significant advance of this electrospinning technique toward practical applications for high performance and large‐scale electronics.

Early current window closure effect has been investigated in ZnO bipolar resistive random access memory cell having reactive contacts (aluminum). From spatial oxygen vacancy mapping through low frequency noise (LFN) measurements, a gradual spatial mismatch between the oxygen vacancy profiles of HRS (high resistance state) and LRS (low resistance state) has been found to develop in the cycled cells. A rate limited release of O2– ions from reactive contacts has been mainly attributed to this phenomenon, which suggests that in addition to the field and temperature as the expected natural impetus for ion migration, chemical reaction at the reactive contacts also impacts the complete dissolution of the conductive filament, which leads to the population of a Zn rich donor state (Zni∙∙/Zni∙) in the HRS of post-cycled cells. Zni∙∙/Zni∙is located relatively far from the ZnO conduction band edge; thus, when an LFN probe was fixed to the oxygen vacancy level (V0∙/V0×), it was found to decrease particularly in the HRS of post-cycled cells, which justifies the increase in the HRS current level over the uncycled ZnO cells. We also examined the complementary behavior of the (V0∙/V0×) profile in the LRS of cycled cells, and finally, we validated, through a different nature of current conduction in pre- and post-cycled cells, the current window narrowing effect due to dissimilarities between the spatial profiles of oxygen vacancies.

In this paper we aim to demonstrate the huge spread that can be seen on flicker (1/f) noise figures of advanced MOS devices. In order to do so, we set up a new fully programmable test bench including low frequency noise (1Hz–few Mhz) measurement capability. Once all the hurdles we faced during measurement optimization have been overpassed, we show indeed 1/f noise dispersion over wafer is far larger than simple drive current one. We introduce the first steps of a global study of noise source fluctuation that has still to be led.