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

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.

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

MRS Proceedings ◽

10.1557/proc-831-e8.31 ◽

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.

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The Effect of Indium Surfactant on the Optoelectronic and Structural Properties of MBE Grown Gallium Nitride

MRS Proceedings ◽

10.1557/proc-618-153 ◽

2000 ◽

Vol 618 ◽

Cited By ~ 3

Author(s):

C.F. Zhu ◽

W.K. Fong ◽

B.H. Leung ◽

C.C. Cheng ◽

C. Surya ◽

...

Keyword(s):

Gallium Nitride ◽

Power Spectra ◽

Low Frequency ◽

Rf Plasma ◽

Frequency Noise ◽

Noise Power ◽

Low Frequency Noise ◽

X Ray Diffraction ◽

X Ray ◽

The One

ABSTRACTGallium nitride films were grown by rf-plasma assisted molecular beam epitaxy. A small indium flux was used as surfactant during the growth. The optical and electrical properties of the films grown with and without In surfactant were characterized by investigating the photoluminescence (PL), high resolution x-ray diffraction (HRXRD) and low-frequency noise power spectra. The sample grown in the presence of In surfactant showed a suppressed yellow luminescence (YL) compared to the one grown without In surfactant. Significant reduction in the full width at half maximum of the GaN (0002) x-ray diffraction peak, indicating a better film quality, was obtained when In surfactant was used during growth. Atomic force microscopy studies show that the root mean squared surface roughness for films grown with and without the In surfactant are 5.86 and 6.99 nm respectively indicating significant improvement in surface morphology. This is attributed to the enhanced 2-dimensional growth by In surfactant. A smaller Hooge parameter was obtained from the low-frequency noise measurement for the sample grown with In surfactant indicating that application of In surfactant led to significant reduction in the trap density of the material.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.740-742.934 ◽

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.

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