Determination of dopant-concentration diffusion length and lifetime variations in silicon by scanning electron microscopy

Y., Jim; Gatos, H. C.

doi:10.1063/1.326336

Cited by 42 publications

(11 citation statements)

References 14 publications

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“…25 was produced under such conditions. This effect can only be understood in terms of a decrease in either 5 or 'T such that (d) and (e), respectively (Chi and Gatos 1979). r = wi PST is increased.…”

Section: A Inhomogeneitiesmentioning

confidence: 94%

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Charge collection scanning electron microscopy

Leamy¹

1982

Journal of Applied Physics

761

319

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A novel apparatus for in situ compression of submicron structures and particles in a high resolution SEM Rev. Sci. Instrum. 83, 095105 (2012) Foucault imaging by using non-dedicated transmission electron microscope Appl. Phys. Lett. 101, 093101 (2012) New Products Rev. Sci. Instrum. 83, 079501 (2012) Towards secondary ion mass spectrometry on the helium ion microscope: An experimental and simulation based feasibility study with He+ and Ne+ bombardment This review encompasses the application of the scanning electron microscope to the study and characterization of semiconductor materials and devices by the Electron Beam Induced Conductivity (EBIC) method. In this technique, the charge carriers generated by the electron beam of the microscope are collected by an electric field within the material and sensed as a current in an external circuit. When employed as the video signal of the SEM, this collected current image reveals inhomogeneities in the electrical properties of the material. The technique has been used to determine carrier lifetime, diffusion length, defect energy levels, and surface recombination velocities. Charge collection images reveal the location of p-n junctions, recombination sites such as dislocations and precipitates, and the presence of doping level inhomogeneities. Both the theoretical foundation and the practical aspects of these effects are discussed in a tutorial fashion in this review. PACS numbers: 07.80. + x, 61.16.Di, 72.20. -i GLOSSARY OF SYMBOLS C = ill II = image contrast. {j = SrlL = recombination velocity -;-diffusion velocity. D, De' Dh = Diffusion coefficient (D) for electrons (De), and for holes (D h ) (cm2/sec). E = electron beam energy (eV). Eeh = carrier pair creation energy (eV). E bg = band-gap energy (eV). ET = carrier trap energy level (eV). S = electric field strength (V Icm). E = dielectric constant. f = energy fraction of the incident electron beam that is reflected from the sample surface. g = carrier pair generation rate (cm -3).I = electric current (amps). Ib = SEM electron beam current (amps). Ig = IbE(1 -f)IEeh = maximum beam generated current (amps). Icc = collected current (short circuit current) (amps). Is = saturation current of a p-n junction (amps). J e , J h = electron (J e ) or hole (J h ) flux (cm-2 sec-I ). k = Boltzmann's constant = 1.38 X 10-23 I/'K. Leo L h = diffusion length for electrons (L e) and holes (L h ) (cm). m = mass (gms). n = equilibrium electron density (cm -3). iln = excess electron density (cm-3 ). NT = carrier trap density (cm-3 ). NB = net ionized impurity density (cm-3 ). p = equilibrium hole density (cm -3). ilp = excess hole density (cm -3). q = electronic charge = 1.6 X 10-19 C. R = recombination rate (sec-I).R e = electron range (cm). p = density (gm/cm 3 ). S = surface recombination velocity (cm/sec). l: = charge collection efficiency. 0', U e , Uh = capture cross section (0') for electrons (u e ) and holes (u h ) (cm 2 ). T = temperature (OK). T, T e , Th = lifetime (T) for electrons (Te) and for holes (T h ) (sec). T...

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Section: A Inhomogeneitiesmentioning

confidence: 94%

“…At very high doping levels, however, Chi and Gatos (1979) have recently demonstrated the inhomogeneity contrast shown in Fig. 27.…”

Section: A Inhomogeneitiesmentioning

confidence: 95%

Charge collection scanning electron microscopy

Leamy¹

1982

Journal of Applied Physics

761

319

View full text Add to dashboard Cite

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“…29, for the measurement of submicron diffusion length values, the method based on fitting the collected current dependence on beam energy 35,36 is most suitable. In this approach, for a sample with thickness much larger than L and using a Schottky barrier as a collector, the collected current I c can be calculated numerically [37][38][39][40] knowing the distance from the irradiated surface, the normalized depthdose dependence of the electron-hole generation rate and the three-dimensional electron-hole generation rate. The total number of electron-hole pairs created by the electron beam, the beam current and the fraction of beam energy absorbed inside the sample, the metal thickness and the average energy necessary for electron-hole pair creation are all part of this collected current.…”

Section: The Dependence Of Ebic Collection Efficiency On the Accelmentioning

confidence: 99%

Diffusion length of non-equilibrium minority charge carriers in β-Ga2O3 measured by electron beam induced current

Yakimov

Polyakov

Smirnov

et al. 2018

Journal of Applied Physics

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The spatial distribution of electron-hole pair generation in b-Ga 2 O 3 as a function of scanning electron microscope (SEM) beam energy has been calculated by a Monte Carlo method. This spatial distribution is then used to obtain the diffusion length of charge carriers in high-quality epitaxial Ga 2 O 3 films from the dependence of the electron beam induced current (EBIC) collection efficiency on the accelerating voltage of a SEM. The experimental results show, contrary to earlier theory, that holes are mobile in b-Ga 2 O 3 and to a large extent determine the diffusion length of charge carriers. Diffusion lengths in the range 350-400 nm are determined for the as-grown Ga 2 O 3 , while processes like exposing the samples to proton irradiation essentially halve this value, showing the role of point defects in controlling minority carrier transport. The pitfalls related to using other popular EBIC-based methods assuming a point-like excitation function are demonstrated. Since the point defect type and the concentration in currently available Ga 2 O 3 are dependent on the growth method and the doping concentration, accurate methods of diffusion length determination are critical to obtain quantitative comparisons of material quality.

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“…The latter technique allows one to estimate local values of minority carrier diffusion length and the local concentrations of the charged centers that determine the width of the space charge region. [15][16][17][18][19] In was used for ohmic contacts, and Schottky contacts were prepared by vacuum evaporation of Au through a shadow mask. The electrical properties of the ELOG films have been reported previously.…”

Section: Methodsmentioning

confidence: 99%

Neutron Radiation Effects in Epitaxially Laterally Overgrown GaN Films

Polyakov

Smirnov

Говорков

et al. 2007

Journal of Elec Materi

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Neutron radiation effects were studied in undoped n-GaN films grown by epitaxial lateral overgrowth (ELOG). The irradiation leads to carrier removal and introduces deep electron traps with activation energy 0.8 eV and 1 eV. After the application of doses exceeding 10 17 cm -2 , the material becomes semiinsulating n-type, with the Fermi level pinned near the level of the deeper electron trap. These features are similar to those previously observed for neutron irradiated undoped n-GaN prepared by standard metal-organic chemical vapor deposition (MOCVD). However, the average carrier removal rate and the deep center introduction rate in ELOG samples is about five-times lower than in MOCVD samples. Studies of electron beam induced current (EBIC) show that the changes in the concentration of charged centers are a minimum in the low-dislocation-density laterally overgrown regions and radiation-induced damage propagates inside these laterally overgrown areas from their boundary with the high-dislocation-density GaN in the windows of the ELOG mask.

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Determination of dopant-concentration diffusion length and lifetime variations in silicon by scanning electron microscopy

Cited by 42 publications

References 14 publications

Charge collection scanning electron microscopy

Charge collection scanning electron microscopy

Diffusion length of non-equilibrium minority charge carriers in β-Ga2O3 measured by electron beam induced current

Neutron Radiation Effects in Epitaxially Laterally Overgrown GaN Films

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