Low-Frequency Noise Characterization in AlGaN/GaN HEMTs with Varying Gate Recess Depths

2004 ◽  
Vol 831 ◽  
Author(s):  
Shrawan. K. Jha ◽  
Bun. H. Leung ◽  
Charles C. Surya ◽  
Heins Schweizer ◽  
Manfred. H. Pilkhuhn
Keyword(s):  
Low Frequency ◽  
Dry Etching ◽  
Frequency Noise ◽  
Noise Power ◽  
Hot Electron ◽  
Low Frequency Noise ◽  
Noise Power Spectral Density ◽  
Noise Measurements ◽  
Gan Hemts ◽  
Gate Recess

ABSTRACTLow-frequency noise measurements were performed on a number of AlGaN/GaN HEMTs with different gate recess depths, which were formed by dry etching. Detailed characterizations of the low-frequency noise properties were performed on the devices as a function of as a function of hot-electron stressing conducted at VD = 10 V and VG = -1.5 V. The room temperature voltage noise power spectral density, SV(ƒ), of the devices were found to show 1/ƒ dependence. A comparison of SV(ƒ) measured from different devices clearly indicate increase in the noise levels for the devices with large recess depths, reflecting the degradation caused by ion-impact induced damage during recess formation. Furthermore, the results of low-frequency noise measurements showed fast degradations for the devices with larger gate recess depths. Our experimental data clearly show that the dry etching process has induced damages in gates.

Reliability Evaluation of 4H-SiC JFETs Using I-V Characteristics and Low Frequency Noise

2013 ◽  
Vol 740-742 ◽  
pp. 934-937
Author(s):  
Hua Khee Chan ◽  
Rupert C. Stevens ◽  
Jonathan P. Goss ◽  
Nicholas G. Wright ◽  
Alton B. Horsfall
Keyword(s):  
Spectral Density ◽  
Power Spectral Density ◽  
Low Frequency ◽  
Frequency Noise ◽  
Noise Power ◽  
Low Frequency Noise ◽  
Noise Sources ◽  
Noise Power Spectral Density ◽  
Power Spectral ◽  
Noise Measurements

Two sets of 4H-SiC signal-lateral JFETs were thermally aged at 400°C and 500°C in furnaces open to air for 1000 hours. I"-" V and low frequency noise measurements were performed on these devices and the results were compared against the as-fabricated sample. The data from I"-" V characterisation demonstrates that the linear and saturated drain-source current decreases monotonically with stress temperature. In addition, the linear characteristics of the JFETs have shifted approximately 1.5V along the drain-source voltage axis. Whilst the devices thermally aged at 400°C show no degradation in magnitude and behaviour in Noise Power Spectral Density (NPSD), the NPSD of 500°C stressed devices has increase approximately 30dB and it shows a full frequency spectrum of 1/ƒ dependency up to 100 kHz. A further investigation of the noise origin reveals that the Normalised Noise Power Spectral Density (NNPSD) of the aged sample is directly proportional to RDSwhich is similar to the as-fabricated sample. Thus we hypothesize that the existing noise sources have intensified possibly due to the evolution of defects.

DEGRADATION OF LOW-FREQUENCY NOISE IN AlGaN/GaN HEMTS DUE TO HOT-ELECTRON STRESSING

2007 ◽  
Vol 07 (01) ◽  
pp. L91-L100 ◽  
Author(s):  
SHRAWAN K. JHA ◽  
CHANG-FEI ZHU ◽  
MANFRED H. PILKUHN ◽  
CHARLES SURYA ◽  
HEINZ SCHWEIZER
Keyword(s):  
Low Frequency ◽  
Degradation Process ◽  
Open Circuit ◽  
Excess Noise ◽  
Second Phase ◽  
Frequency Noise ◽  
Noise Power ◽  
Hot Electron ◽  
Low Frequency Noise ◽  
Gan Hemts

We report on the degradation of low-frequency excess noise in recessed gate AlGaN/GaN HEMTs due to hot-electron stressing. The I-V characteristics and the low-frequency noise power spectral densities, SV(f), of the open circuit voltage fluctuations across the drain source terminal were characterized with the stress time. Based on these results, we observed that the overall low-frequency noise degradation process can be identified to occur in two distinct phases. In the first phase, devices initially show fluctuations in the noise properties around a relatively constant average value. Detailed characterizations of the gate-source bias, VGS, dependence of SV(f) at cryogenic temperatures indicate signature-patterns in the variations of SV(f) as a function of VGS. This is shown to arise from the modulation of the percolation paths of the carriers in the two-dimensional electron gas (2DEG). The onset of the second phase of degradation arises from the irreversible generation of interface states at the AlGaN/GaN hetero-interface.

scholarly journals Measurements of Low Frequency Noise of Infrared Photo-Detectors with Transimpedance Detection System

2014 ◽  
Vol 21 (3) ◽  
pp. 461-472 ◽  
Author(s):  
Łukasz Ciura ◽  
Andrzej Kolek ◽  
Waldemar Gawron ◽  
Andrzej Kowalewski ◽  
Dariusz Stanaszek
Keyword(s):  
Dark Current ◽  
Detection System ◽  
Power Spectra ◽  
Low Frequency ◽  
Frequency Noise ◽  
Noise Power ◽  
Low Frequency Noise ◽  
Leakage Resistance ◽  
Noise Measurements ◽  
Hgcdte Detector

Abstract The paper presents the method and results of low-frequency noise measurements of modern mid-wavelength infrared photodetectors. A type-II InAs/GaSb superlattice based detector with nBn barrier architecture is compared with a high operating temperature (HOT) heterojunction HgCdTe detector. All experiments were made in the range 1 Hz - 10 kHz at various temperatures by using a transimpedance detection system, which is examined in detail. The power spectral density of the nBn’s dark current noise includes Lorentzians with different time constants while the HgCdTe photodiode has more uniform 1/f - shaped spectra. For small bias, the low-frequency noise power spectra of both devices were found to scale linearly with bias voltage squared and were connected with the fluctuations of the leakage resistance. Leakage resistance noise defines the lower noise limit of a photodetector. Other dark current components give raise to the increase of low-frequency noise above this limit. For the same voltage biasing devices, the absolute noise power densities at 1 Hz in nBn are 1 to 2 orders of magnitude lower than in a MCT HgCdTe detector. In spite of this, low-frequency performance of the HgCdTe detector at ~ 230K is still better than that of InAs/GaSb superlattice nBn detector.

MEASUREMENT OF FLICKER NOISE AS A DIAGNOSTIC TOOL FOR HOT-ELECTRON DEGRADATION IN GaN-BASED LEDS

2007 ◽  
Vol 07 (04) ◽  
pp. L419-L428
Author(s):  
W. K. FONG ◽  
K. K. LEUNG ◽  
H. F. LUI ◽  
P. K. A. WAI ◽  
C. SURYA ◽  
...  
Keyword(s):  
Diagnostic Tool ◽  
Flicker Noise ◽  
Light Output ◽  
Low Frequency ◽  
Excess Noise ◽  
Frequency Noise ◽  
Noise Power ◽  
Hot Electron ◽  
Noise Power Spectral Density ◽  
Rate Of Increase

Hot-electron stressing on GaN -based light emitting diodes (LEDs) has been performed using a dc stressing current. Detailed characterizations on the degradations in the optoelectronic and low-frequency noise properties of the devices have been conducted. Experimental results on I-V, electroluminescence (EL) and the integrated light output of the devices exhibit significant degradations with the stress time. Investigations on the low-frequency excess noise of the devices show that the degradations of the device properties arise from the generation of interface states at the InGaN / GaN heterointerface due to hot-electron stressing. Over two orders of magnitude increase in the current noise power spectral density, SI(f), is typically observed prior to the failure of the devices. Furthermore, it is shown that the initial rate of increase in SI(f) resulting from a dc current stress time of 48 hours is strongly correlated to the lifetimes of the devices demonstrating that flicker noise measurement can be used as a diagnostic tool for hot-electron hardness of the device.

scholarly journals LOW-FREQUENCY NOISE MEASUREMENTS OF IR PHOTODETECTORS WITH VOLTAGE CROSS CORRELATION SYSTEM

Measurement ◽  
2021 ◽  
pp. 109867
Author(s):  
Krzysztof ACHTENBERG ◽  
Janusz MIKOŁAJCZYK ◽  
Carmine CIOFI ◽  
Graziella SCANDURRA ◽  
Krystian MICHALCZEWSKI ◽  
...  
Keyword(s):  
Cross Correlation ◽  
Low Frequency ◽  
Frequency Noise ◽  
Low Frequency Noise ◽  
Ir Photodetectors ◽  
Noise Measurements ◽  
Correlation System
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