Generation–recombination noise studied in hydrogenated amorphous silicon

Verleg, P.A.W.E.; Dijkhuis, J. I.

doi:10.1016/s0022-3093(99)00827-3

Cited by 8 publications

(5 citation statements)

References 16 publications

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“…Figure a shows the noise spectra of the films of series #1 which have a Lorentzian behavior for frequencies below 30 Hz, and above that, the behavior is of 1/ f noise type. This behavior has been observed as well in a‐Si:H . There is also a tendency of reduction in the noise for f > 30 Hz in the films deposited at pressures in the range of 1200–1400 mTorr, which can be related to a lower network disorder in the films.…”

Section: Resultssupporting

confidence: 63%

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐Si_xGe_1−x:H) Thin Films for Infrared Detection Applications

Jiménez

Moreno

Torres

et al. 2018

Physica Status Solidi (a)

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In this paper, the characterization and optimization of polymorphous silicon‐germanium (pm‐SixGe1−x:H) thin films prepared by plasma‐enhanced chemical vapor deposition (PECVD) are reported in order to use them as thermo‐sensing films on infrared detectors. Two series of pm‐SixGe1−x:H thin films are fabricated and characterized. In the first series, the pressure is varied in a wide range (600–2000 mTorr) using the same SiH4 and GeH4 flow rates, while in the second series the flow rate of GeH4 is varied in the range of R = 10–90%. Fourier transform infrared spectroscopy (FTIR) confirms the large incorporation of germanium (Ge) in the solid phase. The aim is to optimize the films in terms of the temperature coefficient of resistance TCR (% K−1), room temperature conductivity, and noise. A significant variation in the TCR values from 3.1 to 9.9% K−1 and in the room temperature conductivity by about six orders of magnitude is observed. Finally, noise spectral density characterization is performed to evaluate the application of the pm‐SixGe1−x:H films as thermo‐sensing elements in high performance infrared detectors (microbolometers).

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Section: Resultssupporting

confidence: 63%

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐Si_xGe_1−x:H) Thin Films for Infrared Detection Applications

Jiménez

Moreno

Torres

et al. 2018

Physica Status Solidi (a)

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“…The 1/f noise is attributed to charge number (McWhorter model) or mobility fluctuations (Hooge model) in the conductivity [1]. In a-Si:H material, 1/f noise has been correlated to hydrogen content and microcrystallinity [9], and generation-recombination noise [10]. In addition, authors have related 1/f noise with variable range hopping [11,12].…”

Section: Introductionmentioning

confidence: 99%

Temperature Dependence of 1/f Noise and Electrical Conductivity Measurements on p-type a-Si:H Devices

et al. 2013

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Noise and electrical conductivity measurements were made at temperatures ranging from approximately 270°K to 320°K on devices fabricated on as grown Boron doped p-type a-Si:H films. The room temperature 1/f noise was found to be proportional to the bias voltage and inversely proportional to the square root of the device area. As a result, the 1/f noise can be described by Hooge's empirical expression [1]. The 1/f noise was found to be independent of temperature in the range investigated even though the device conductivity changed by a factor of approximately 4 over this range. Conductivity temperature measurements exhibit a T -0.25 dependence, indicative of conduction via localized states in the valence band tail [2,3]. In addition, multiple authors have analyzed hole mobility in a-Si:H and find that the hole mobility depends on the scattering of mobile holes by localized states in the valence band tail [4][5][6][7]. We conclude that the a-Si:H carrier concentration does not change appreciably with temperature, and thus, the resistance change in this temperature range is due to the temperature dependence of the hole mobility. Our results are applicable to a basic understanding of noise and conductivity requirements for a-Si:H materials used for microbolometer ambient temperature infrared detection.

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“…A variety of noise measurements of a-Si:H have been reported over the past twenty years many of which are contradictory [1]. Working with sandwich structures where the current path is transverse to the surface, Verleg and Dijkhuis measured noise power spectra that deviate from a simple power law [2]; the spectra bend downward in an approximation of a Lorentzian. Other studies of a-Si:H with coplanar electrodes, where the current is longitudinal to the surface, found either simple 1/f a power laws with a in the range 0.7-1 or deviations from a power law but in the opposite direction [3,4], i.e.…”

Section: Introductionmentioning

confidence: 99%

1∕f noise in hydrogenated amorphous silicon–germanium alloys

Johanson

Güneş

Kasap

2003

IEE Proc., Circuits Devices Syst.

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Measurements were made of conductance noise of a-Si:H and a-Si 1Àx Ge x :H in two different geometries: one where the current flow is transverse to the surface and the other where it is longitudinal to the surface. Because of the large change in sample resistance between the two geometries, it was not possible to measure both geometries at the same temperature. For both geometries, alloyinzg with up to 40% Ge reduces the noise magnitude by several orders of magnitude over that found in a-Si:H. The decrease is incompatible with several popular noise models. Extrapolating the temperature trends for each geometry shows that it is possible that the noise observed in the transverse samples has the same origin as the higher frequency part of the double power law spectra observed in the longitudinal samples.

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Generation–recombination noise studied in hydrogenated amorphous silicon

Cited by 8 publications

References 16 publications

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐Si_xGe_1−x:H) Thin Films for Infrared Detection Applications

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐Si_xGe_1−x:H) Thin Films for Infrared Detection Applications

Temperature Dependence of 1/f Noise and Electrical Conductivity Measurements on p-type a-Si:H Devices

1∕f noise in hydrogenated amorphous silicon–germanium alloys

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Generation–recombination noise studied in hydrogenated amorphous silicon

Cited by 8 publications

References 16 publications

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐SixGe1−x:H) Thin Films for Infrared Detection Applications

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐SixGe1−x:H) Thin Films for Infrared Detection Applications

Temperature Dependence of 1/f Noise and Electrical Conductivity Measurements on p-type a-Si:H Devices

1∕f noise in hydrogenated amorphous silicon–germanium alloys

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Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐Si_xGe_1−x:H) Thin Films for Infrared Detection Applications

Effect of Pressure and Flow Rates on Polymorphous Silicon‐Germanium (pm‐Si_xGe_1−x:H) Thin Films for Infrared Detection Applications