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Iron introduces a donor level at about E c-0.4 eV in n-type silicon. In this work, the electrical properties of this donor state have been studied by deep-level transient spectroscopy (DLTS). It is found, by resolving the overlapping DLTS peaks obtained after room temperature annealing, that the donor decomposes into several other states. Isothermal annealing of samples containing different amounts of phosphorus show that phosphorus has no significant effect on the annealing decay constant of the donor, indicating that phosphorus atoms do not take part in the annealing decay of the donor. A Poole-Frenkel field emission effect is observed in the donor level as expected for donors in n-type silicon.

In iron-related deep levels in n-type silicon, the introduced concentration of E c-0.21 eV(B) and E c-0.41 eV(C) levels decrease with increasing the diffusion time at 1160°C, indicating that the formation process includes the conversion process into other types of complexes. The concentration of the C level decays exponentially with the duration of isothermal annealing up to 200°C, the time constant activation energy being 0.65 eV. The results indicate that the observed defects are due to the intermediate states in consecutive reactions of iron-related complex formation.

The temperature coefficient of resistance for n- and p-type silicon has been calculated between −50 and 125°C for a wide range of concentrations and levels of compensation. These results provide a useful guide for the design of silicon integrated resistors.

Platinum-silicon Schottky diodes on epitaxial layers have been subjected to argon ion bombardment, prior to metal evaporation, with doses in the 10 14 ions/cm 2 range and with energies between 1 and 3.5 KeV. By transient capacitance technique four electron traps have been found. The oxygen-vacancy pair (O-V) located at 0.17 eV below the conduction band, the double negatively charged divacancy (V-V = ) at 0.23 eV and the phosphorous-vacancy pair (P-V) at 0.44 eV are observed. One more unknown level at 0.36 eV which could be oxygen-related is also found.

The magneto-quantum transport phenomena of silicon (110) n -type inversion layers directly reveal the presence of two types of electrons in i = O and O' electric subband states from their respective quantum oscillations. While the higher i = O' states are occupied by only about 6% of the total electron concentration in our samples, the i = O electrons populate two valley pairs each, the level ladders of which are shifted in energy by less than the Landau splitting in the range where quantum oscillations are observed. We propose this effect to originate from a slight misorientation (Δθ i = O valleys are alternatingly occupied in pairs with increasing Landau quantum number in our (110) surfaces contrary to former conclusions on samples with comparable properties. The effect of the magnitude of Δθ on the resulting magneto-quantum oscillations is unimportant for 0

Electrical properties of deep levels introduced during quenching from high temperatures in VPE layers of n-type silicon are investigated. Two levels at 0.51 and 0.32 eV below the conduction band are found. The capture cross section of the deeper level is large (> 1.0 × 10−15 cm2). The capture cross section of the shallower level is of the order of 10−16 cm2 and has a T−2 dependence. It is suggested that the deeper level is due to the positively charged state and the shallower level to the neutral charge state of the same defect. The probable origin of the defect is the contamination by iron during wafer processing. The pressure coefficients of the energy levels and the electron capture cross sections are determined. Die elektrischen Eigenschaften von tiefen Niveaus, die wahrend der Abschreckung von hohen Temperaturen in n-leitenden VPE-Siliziumschichten eingefuhrt werden, werden untersucht. Zwei Niveaus bei 0,51 und 0,32 eV unterhalb des Leitungsbandes werden gefunden. Der Einfangquerschnitt des tieferen Niveaus ist gros (> 1,0 × 10−15 cm2). Der Einfangquerschnitt des flacheren Niveaus ist von der Gros enordnung 10−16 cm2 und hat eine T−2-Abhangigkeit. Es wird angenommen, das das tiefere Niveau von dem positiv geladenen Zustand und das flachere Niveau durch den neutralen Ladungszustand desselben Defekts hervorgerufen wird. Die wahrschcinliche Ursache des Defekts ist die Verunreinigung mit Eisen wahrend des Wafer-Prozesses. Die Druck-koeffizienten der Energieniveaus und der Elektroneneinfangquerschnitte werden bestimmt.

The tilted field method is used to measure the coincidence of spin-split Landau levels of different Landau quantum numbers in (100) n-type silicon inversion layers. At constant magnetic field perpendicular to the surface the peak values of Shubnikov-de Haas oscillations are analyzed as a function of the tilt angle ϕ, where ϕ is the angle between the surface normal and the magnetic field. Pronounced maxima of sxx for Corbino devices and of sxx for Hall devices are found at the coincidence condition. The electronic g-factor determined from the coincidence is substantially larger than the bulk value contrary to a recent publication, where experimental evidence for g = 2 was claimed. It is also shown that the Hall component does not falsify the results when the angular dependence of the resistivity maxima is investigated at constant total magnetic fields for a fixed Landau quantum number. An (100) n-Typ Silizium-Inversionsrandschichten wird durch Drehen der Probe im Magnetfeld die Koinzidenz spinaufgespaltener Landauniveaus mit unterschiedlicher Landauquantenzahl gemessen. Die Maximal werte der Shubnikov-de Haas-Oszillationen werden bei konstantem Magnetfeld senk-recht zur Oberflache als Funktion des Drehwinkels ϕ untersucht, wobei ϕ der Winkel zwischen der Oberflacheimormalen und dem Magnetfeld ist. Bei der Koinzidenz werden ausgepragte Maxima in sxx fur Corbino-Proben und in gxx fur Hall-Proben beobachtet. Der daraus bestimmte elektronische g-Faktor ist wesentlich groser als der Volumenwert im Gegensatz zu einer kurzlichen Veroffentlichung, in der die Autoren behaupten, den experimentellen Beweis fur g = 2 gefunden zu haben. Ferner wird gezeigt, das die Hallkomponente die Ergebnisse nicht verfalscht, wenn die Winkelabhangigkeit der Widerstandsmaxima bei konstantem Gesamtmagnetfeld fur eine feste Landauquantenzahl untersucht wird.

In this paper the technique of infrared angular spectroscopy applied to the characterization of epitaxial layers of n-type silicon grown on N+ or P+ substrates is illustrated. Some results are reported and discussed concerning films having a free-carrier concentration ranging from 1014 cm−3 to 1017 cm−3 and thickness of the order of 10 μm. A significant comparison with results obtained by other techniques (four-point probe, spreading resistance, C−V plots, etc.) is performed and a few simple conclusions are drawn.

From capacitance measurements, the thermal capture cross-section of electrons at neutral gold centres is determined through the time dependence of the net ionized recombination centres concentration to σ = 1.24 × 10−16 (T/300)−(0.21 ± 0.03) cm2 in the temperature range 80 to 205 K. La section de capture thermique des electrons sur l'or neutre est deduite de la dependance temporelle de la densite de centres profonds ionises, mesuree par une technique capacitive. Pour le domaine de temperature 80 a 205 K le resultat est: σ = 1,24 × 10−16 (T/300)−(0,21 ± 0.03) cm2.

Capacitance bridge measurements of loss on irradiated phosphorus-doped silicon specimens at low temperatures are reported. A peak in AC conductance at 39K is seen after irradiation. Some annealing characteristics are described. It is argued that the behaviour is not associated with divacancies or single-vacancy defects.

Etude experimentale de la stabilisation de photoanodes au silicium de type n a revetement de polymere par liaison electrostatique d'ions actifs du point de vue oxydoreduction

We investigate the possibility that in a semiconducting surface inversion layer the ground state has charge-density waves in each of the two equivalent subbands. The two charge-density waves are identical except that they are completely out of phase with each other. Such a state, referred to as a valley-density wave (VDW), need not be accompanied by a lattice distortion. A density-functional formalism is used to study the instability toward formation of a VDW ground state. It is found that under certain conditions the VDW state has a lower energy than the paramagnetic state. A similar conclusion is drawn on the basis of Hartree-Fock treatment of VDW state.

Radiation-induced accumulation and annealing processes of radiation defects with level Ec–0,22 eV in silicon of various perfection are analysed and it is concluded that they consist of oxygen and two vacancies (oxygen-divacancy complex).

Deep levels in iron‐doped n‐type silicon have been investigated by deep‐level transient spectroscopy (DLTS). Three deep levels of Ec−0.29 eV (E1), Ec−0.36 eV (E2), and Ec−0.48 eV (E3) were observed. The concentration of E1 and E2 levels increased during the storage at room temperature. The depth profile of the E3 level concentration indicates the out‐diffusion and precipitation of the defects related to the E3 level. In addition, after annealing at 80 °C for 30 min, the E2 and E3 concentrations decreased and then recovered at room temperature. These results suggest that the defects related to these levels are mobile during quenching and storage at room temperature. The temperature dependence of the E3 level concentration shows a formation energy of about 2 eV, which is smaller than that of interstitial iron, and the E3 level concentration is two orders of magnitude lower than the concentration of interstitial iron. The origins of these levels are probably loosely associated iron‐related complexes such as ...

The energy levels and degeneracy ratios of magnesium in n-type silicon have been determined by Hall effect measurements with the least square method. Magnesium ions appear to occupy two different sites and show different electrical properties. The first is amphoteric and exhibits an acceptor level at Ec − 0.115 eV (±0.002 eV), degeneracy ratio γI− = 2.5 as well as a donor level at Ec − 0.40 eV (±0.01 eV), γIII+ = 1. The second exhibits a donor level at Ec − 0.227 eV (±0.004 eV), degeneracy ratio γ II + = 1 2.5 . The physical nature of these Mg associated site is unknown.

Values of the Nernst-Ettingshausen coefficient are given for n-type silicon containing 3*1019-6*1025m-3 phosphorus or arsenic atoms, over the range 77-300 K, in a field of 1.00 T. The results are discussed briefly, the effect of mixed scattering being considered.

The ground state for n-type silicon inversion electrons at the Si (100)/SiO2 interface is studied theoretically as a function of temperature, applied uniaxial stress and gate voltage. Calculations on a model that includes charge-density-wave states under favourable conditions provide results which allow a consistent and unified description of a whole series of experimental data that otherwise lead to divergent interpretations. One novel aspect of the theory is the ability of temperature and/or stress to induce and destroy a broken-symmetry ground state with a first- and a second-order phase transition. Parameters in the theory can, in principle, be used to estimate the effectiveness of screening in the inversion layer and the strength of electron-lattice coupling at the interface.

The analysis of surface quantum oscillations in strong magnetic fields at gate voltages, where the valley splitting is not resolved, show, that the σ xx measurements can be successfully simulated with different sets of data for the valley splitting and the lineshape of the density of states. From experimental σ xx data, measured at different magnetic field directions relative to the surface normal, only the lineshapes of the conductivity contributions σ N,s ( E ) of spin split levels (which consist of two valley split lines) and an upper limit Δυ max for the valley splitting can be deduced (Δυ max ≈ 1 meV at n = 4 × 10 12 cm −2 and B ⊥ = 7.4 Tesla). Measurements at different substrate bias voltages and the analysis of Hall conductivity data seem to indicate, that the valley splitting is substantially smaller than Δυ max .

Conductivity and Hall effect measurements have been performed on n‐type silicon samples with phosphorus doping concentrations varying from 4.4×1018 to 8.65×1019 cm−3 and for temperatures ranging from 77 to 300 °K. It is demonstrated that, on the whole, the Bonch‐Bruevich theoretical model allows a satisfactory interpretation of the experimental results.

The ion damaged effect and subsequent isothermal annealing in boron-implanted Si was studied by positron annihilation lifetime measurements. The mean positron lifetime in preimplanted n-type Si is 243 psec. The variation of mean lifetime is detectable when the implanted boron dose is greater than 1.0x10 15 /cm 2 . The saturated mean positron lifetime (247 psec) occurs when the implantation dose reaches 2.5x10 15 /cm 2 . The mean electron density of the positron sensitive defects is estimated to be about 85% less than that in the perfect parts of the crystal. Isothermal annealing was held in every 5-minute step at 1000°C. In the first step, the positron lifetime in the implanted sample increases slightly and then decreases completely to its initial state in the 3rd step. Sheet resistance of the sample monitored by 4-point probe method has been found closely related to the positron lifetime.

Deep level transient spectroscopy measurements on electron bombarded floating-zone n-Si Schottky diodes are reported. Activation energies and capture cross-sections of five observed majority-carrier traps (Ec – 0.15 eV, Ec – 0.21 eV, Ec – 0.28 eV, Ec – 0.33 eV, and Ec – 0.45 eV) are examined. Depth profiling and electric field effects on the thermal emission of the traps are also investigated. Identifications made by reference to the published literature are discussed. Es werden DLTS-Messungen an elektronenbestrahlten Schottkydioden aus n-leitendem zonengezogenem Si durchgefuhrt. Aktivierungsenergien und Einfangsquerschnitte von funf beobachteten Majoritatstragerhaftstellen (Ec – 0,15 eV, Ec – 0,21 eV, Ec – 0,28 eV, Ec – 0,33 eV und Ec – 0,45 eV) werden untersucht. Tiefenprofil und Einflusse des elektrischen Feldes auf die thermische Emission der Haftstellen werden ebenfalls untersucht. Die Identifizierung anhand der Literaturdaten wird diskutiert.

Based on two screened donor potential models and taking into account the electron-electron interaction effect in the electron-donor interaction, the band-gap narrowing (BGN) in n-type doped silicon at 300 K is investigated. The BGN effect is expressed in terms of physical BGN (ΔEg), a change in density of conduction-band states (Γn) and the change in effective electron (hole) mass (γn (γp)). In fact, electrical BGN is found to be given by ΔE g, elec. ∗ = ΔE g + Γ n γ n + Γ p + ΔE g , fd ≅ ΔE g + Γ n , where ΔEg,fd represents the Fermi-Dirac statistics effect. Our results of ΔE g and ΔE tg , elec. ∗ agree fairly with corresponding observed results, and the large values of Γ n ≅ ΔtE g , elec. ∗ − ΔE g obtained at high donor concentration are in good agreement with a qualitative discussion given by Marshak and Van Vliet. Finally, the present results for the effective intrinsic-carrier concentration nie are compared with corresponding results observed by Tang.

This paper describes investigations on process induced crystal defects in n-type silicon material of both Czochralski- and zone-floating-techniques (dislocation-free). The heating and cooling processes, the oxide thickness, mechanical stresses near the diffusion windows, the mask pattern geometry concerning diffusion and the surface concentration of the doping material have been specially investigated. The influence of those technological parameters on the generation of crystal defects in the production of electronic devices is investigated and discussed. Es wurden Untersuchungen zur prozesinduzierten Bildung von Strukturdefekten fur n-leitendes versetzungsfreies Czochralski- und zone-floating-Silizium durchgefuhrt. — Besondere Beachtung fanden die Aufheiz- und Abkuhlvorgange, die Oxidschichtdicke, mechanische Spannungen an den Deckschicht-Substratubergangen der Diffusionsfenster, Diffusionsmaskengeometrie und die Oberflachenkonzentration bei der Diffusion. Der Einflus der genannten technologischen Parameter auf die Bildung von Gefugedefekten im Bauelementeprozes wird untersucht und diskutiert.

The temperature independence of the capture cross-section of the neutral Au-acceptor level for electrons in silicon, σn, in the range of 172 to 316 K is found. The measurements were performed at high-resistivity, Au-compensated single-injection SCLC diodes by means of a pulse and a small-signal capacitance method. In der vorliegenden Arbeit wird die Temperaturunabhangigkeit des Wirkungsquerschnitts σn des neutralen Au-Akzeptorniveaus fur Elektronen in Silizium im Temperaturbereich 172 bis 316 K nachgewiesen. Die Messungen wurden an hochohmigen Au-kompensierten Einfachinjektions-SCLC-Dioden mit Hilfe einer Puls- und einer Kleinsignal-Kapazitatsmethode durchgefuhrt.

When n-type silicon is heated to 1200 degrees C in ultra-high vacuum to produce atomically clean surfaces it is found that the outer layer becomes p-type to a depth of several microns. The conductivity type was determined by thermal probing and the carrier density by four-point-probe measurement of sheet resistivity combined with a measurement of junction depth by scanning electron microscopy. The hole concentration could be as high as 2*1015 cm-3 in material which had an electron concentration of 2*1013 cm-3.

The properties of silver-silicon interfaces formed by cleaving n-type silicon in ultra high vacuum (UHV) in a stream of evaporating silver atoms were studied. The barrier heights of these contacts were measured at different temperatures by using C - V techniques. All measurements were performed in UHV. The dependence of the barrier height upon temperature did not follow the temperature dependence of the Si band gap as it is usually found. The measured temperature behavior depended on the roughness of the Si surface. The temperature behavior can be explained by assuming a specific band structure of the interface states. For Ag contacts on atomically smooth n-type Si, the interface states were found to be arranged in two bands, one band 4 × 10 −3 eV wide with acceptor type states 0.18 eV below the intrinsic level E i and a density of 10 17 states/cm 2 eV, and the other 1 eV wide with donor type states with its upper edge 0.28 eV below E i , and a density of 4 × 10 14 states/cm 2 eV.

A Kramers-Kronig analysis (KKA) of various heavily doped p- and n-type silicon crystals has been carried out. The concentration and wavelength dependence of n, k and α is presented. The α values obtained from the KKA are in good agreement with values expected from the Drude model indicating that contradictions found previously by Schuman et al. could be due to experimental uncertainties. The complex dielectric function provided by the KKA permits the determination of various free carrier parameters. It is shown that under certain conditions a mean relaxation time τɽ can be obtained directly from the KKA-results. This τɽ differs from τɽHall by a factor of 1.1–1.2 in the case of the samples investigated.

The carrier concentration and the Hall mobility in plastically deformed n-type silicon crystals are measured as a function of the temperature and the density of dislocations introduced. The results show that the deformation-induced defects act as acceptors. The acceptor level is found to be located between 0.34 eV and 0.42 eV above the valence band, being higher for higher densities of dislocations introduced.

Surface Shubnikov-de Haas oscillations have been measured in p-type channels of (110) silicon field effect transitors between 1.4 and 4.2 K in magnetic fields up to 10 Tesla. Two electric subbands were revealed and the effective masses of the holes in both bands could be determined. For one subband the dependence of the mass on the surface electric field was investigated. At low gate voltages the g-factor of the holes was measured from the spin splitting of the Landau-levels.

The transverse and Hall resistance are investigated under quantizing electric and magnetic fields in n -type silicon (100) MOSFET inversion layers. The transverse resistance ρ xx vanishes within finite ranges of the gate voltage where the concentration of channel conduction electrons is constant. The variation of the oscillatory period towards low gate voltages is not compatible with the concept of carrier localization and therefore can be understood by charge transfer into states outside the surface channel.

A detailed examination of the possible intervalley electron-electron interactions in n-type silicon inversion layers leads to a model Hamiltonian of considerably greater complexity than that studied by Kelly and Falicov. While the theory of broken-symmetry states retains its structure, significant new points of detail emerge. At zero stress at the Si(111)/SiO2 interface, all six valleys participate in the ground state; but quite small stresses suffice to destroy such a state, while at the Si(100)/SiO2 interface a broken-symmetry state at intermediate stress is rather easier to stabilise.

Les calculs des durees de vie Auger pur sont en accord avec les donnees experimentales dans une large gamme de temperatures. Les resultats experimentaux sont ainsi expliques sans la prise en compte d'une recombinaison assistee par des phonons

EPR measurements have been made on (100) n type silicon wafers implanted with 200 keV 16O+ ions in the dose range (0.5–1.4) × 1018 O+ cm−2 and at implantation temperatures, Ti, in the range 250–600°C. Several types of defect are observed including E'1 centres. For a dose of 1.4 × 1018 O cm−2 the E'1 concentration is found to increase from 1.5 × 1014 to 2.3 × 1014 cm−2 as Ti increases from 250 to 600°C. Measurements on lower dose samples indicate that E'1 defects are present in SiO2 precipitates as well as in the buried SiO2 layer. The E'1 EPR signal only starts to decrease for annealing temperatures ⪸ 450 ° C.

Shubnikov-de Haas oscillations have been studied for (110) and (111) n -type silicon inversion layers. The measured cyclotron masses m c = (0.38 ± 0.03) m 0 and m c = (0.40 ± 0.03) m 0 for (110) and (111) planes, respectively, are larger than theoretically predicted values. The experimental valley degeneracy factor g v = 2 ± 0.2 for both orientations is also at variance with self consistent calculations. The electronic g -factor depends on the surface carrier concentration and is enhanced over its bulk value. There was no evidence for the occupation of other subbands.