Polarizabilities of shallow donors in silicon

Capacitance measurements on N-type As, P, and Sb-doped Si samples have been made between 4.2 and 1.35°K, from 0.3 to 100 kHz as a function of (N_D ? N_A) [high purity to 2.7 × 10¹⁸/cm³]. From the dielectric constant variation with (N_D ? N_A) donor polarizabilities α_AS, α_P, and α_Sb are found respectively to be $\text{1.0±0.1, 2.4±0.4,}\text{and}\text{3.1±0.3 × 10}{}^5\text{A}\text{?}{}^3$.     

Polarizabilities of shallow donors in silicon — A comment

A recent experiment on n-type As, P and Sb-doped Si samples to study the donor polarizabilities by the capacitance measurement should be reinterpreted on the basis of the d.c. resistivity data below 4.2 K together with the concentration vs resistivity relations at room temperature.     

Polarizability of shallow donors in silicon - A reply

A reply to the comment of Yoshihiro and Yamanouchi is made explaining the role of Schottky barriers on the capacitance results determined previously by Bethin, Castner, and Lee. Earlier concentration-dependent dielectric constant measurements for Sb-doped Ge are also noted.     

Determination of the deformation potential of shallow donors in silicon

The stress dependence of the energy of the ground state of group V impurities (P, Sb) in silicon was investigated by measurement of the Hall effect in a wide range of pressures. A conclusion was reached that the deformation potential of the lowest impurity state of shallow donors (Ξ¹_u) in silicon differs from the deformation potential of the conduction band (Ξ_u), the value of this difference being dependent on the type of the impurity. According to our data, the most probable values for ($\text{Ξ}{}_{\mathrm{u}}\text{ Ξ}{}^1{}_{\mathrm{u}}$) are 0.12 eV for phosphorous-doped silicon and 0.06 eV for antimony-doped silicon.     

Central cell effects on the polarizabilities of shallow donors in silicon

With the Topp and Hopfield form for the ionic pseudopotentials, the screened impurity pseudopotentials of the shallow donors P, As and Sb in silicon are obtained in closed form in the linearized Thomas-Fermi model. The results are compared with the screening using a k-dependent dielectric function. Using these impurity pseudopotentials in the multivalley effective mass equation, the binding energies of these donors in Si are estimated variationally. Adopting the Hasse variational method, the polarizabilities of the P, As and Sb donors in Si are computed and are found to be in excellent agreement with the polarizability values of isolated P and Sb in Si, deduced from recent piezocapacitance measurements.     

New results on the Zeeman effect of phosphorus in silicon

We report variational calculations of the quadratic Zeeman effect of phosphorus impurity in silicon, which are compared to our experimental data for B⊥E and B⊥E. It is shown that a small variation of the ratio γ of the transverse and effective masses can lead to a good agreement between theory and experiment for the 2p₀ line. The shift of the central component of the 2p_± line has been found to depend on the polarization of the incident radiation and this fact has not yet been explained. It is also shown that the shift observed for the line ascribed previously to a 1s(A₁)→3d₀ transition can be consistent with this attribution, giving experimental evidence of its electronic nature.     

The effect of band non-parabolicity of shallow donors

We have studied theoretically the effect of non-parabolicity of conduction band on the binding energies of shallow donors. The calculation is carried out in momentum space. We find that the binding energies are increased by 3 to 5 percent for shallow donors in Hg_1-xCd_xTe, GaAs, and InP. The discrepencies between the measured donor ionization energies in GaAs and the value from hydrogenic model are, in a substantial part, due to the non-parabolicity effect.     

Systematics of bound excitons and bound multiexciton complexes for shallow donors in silicon

We report luminescence measurements of transitions involving bound multiple exciton complexes in Si:Sb and Si:As. The systematics of the donor systems Si:P, Si:As and Si:Sb are examined. We find that the splittings between the two observed series of lines are independent of complex number and donor type.     

Generation of shallow nitrogen-oxygen donors as a method for studying nitrogen diffusion in silicon

Physics of the Solid State - The nitrogen concentration distribution C(z) obtained after diffusion of nitrogen from the bulk of a sample toward the surface is determined with a high accuracy...     

Polarizability of shallow donors in EuSe

Permittivity measurements at a microwave frequency 24 GHz have been made on n-type EuSe at low temperatures 4.2–77 K after various annealing times. Consideration of different models for annealing dependent permittivity leads to the polarizability of Se vacancy defects as the most likely explanation. Donor polarizability $\text{α}{}_{\mathrm{d}}\text{= 3.2 × 10}{}^6\text{A}\text{?}{}^3$is found and further an estimation for electron effective mass $\text{m}{}^1\text{= 0.28m}{}_0$.     

Copper donors in silicon

The temperature dependences of the resistivity and of the Hall constant were measured for dislocation-free p-type silicon saturated with copper under different conditions at temperatures round 1000°C. The analysis of the results and their discussion led to the conclusion that the copper donors form complexes the dimension and physical characteristics of which depend on the way the sample is prepared.     

Differential evaluation of the Hall effect in silicon with oxygen-related donors

Three kinds of samples were used to form Co suicides by thermal annealing: firstly, a Co film of about 370 Å thick, evaporated on a (100) single crystal Si (Si ^c /Co); secondly, an evaporated boron-containing Si (Si ^e (B)) layer on the top of the first sample (Si ^c /Co/Si ^e (B)). The last sample is in the Co film of the first sample we deposited a Si^e(B) layer (Si ^c /Co/Si ^e (B)/Co). A laterally uniform CoSi₂ layer can be formed from the second and the third samples by annealing at 450 °C. In the first sample, the CoSi₂ can be formed only at temperatures above 500 °C and the disilicide is laterally less uniform than in the second and third samples. The Schottky barrier heights of the three samples derived from the forward and reverse I–V characteristics show that the barrier height is 0.01–0.02eV higher in the uniform case than in the nonuniform case.     

Quadratic Zeeman corrections for metastable levels of Mg and Ca

Summary The expressions for the corrections to the frequency of the³ P ₂−³ P ₁ and³ P ₁−³ P ₀ π-transitions of Mg and Ca are derived, taking into account the anomalous magnetic moment of the electron as well as the diamagnetic term of the Hamiltonian. Numerical results for²⁴Mg are given.

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Riassunto Si riportano le espressioni analitiche per la correzione di frequenza dovuta all'effetto Zeeman del second'ordine per le transizioni π del tripletto³ P di Mg e Ca. Le correzioni tengono conto del momento magnetico anomalo dell'elettrone e del termine dell'Hamiltoniana responsabile del comportamento diamagnetico dell'atomo. Sono forniti i risultati numerici per il²⁴Mg.

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Резюме Выводятся выражения для поправок к частоте³ P ₂−³ P ₁ и³ P ₁−³ P ₀ π-переходов для Mg и Ca, учитывая аномальный магнитный момент электрона, а также диамагнитный член Гамильтониана. Приводятся численные результаты для²⁴Mg.

     

Zeeman photoluminescence spectroscopy of isoelectronic beryllium pairs in silicon

Isoelectronic beryllium (Be) pair centers in silicon have been studied by photoluminescence spectroscopy under a magnetic field. The photoluminescence of the bound-exciton recombination at this center shows that the number of Zeeman split peaks is the smallest for the magnetic field applied along a $〈100〉$ direction. This result provides direct evidence that the Be pairs orient themselves in $〈111〉$ directions. The $g$ values of the hole and electron in this bound exciton determined by fitting of the Zeeman diagrams support the shallow acceptor character of this isoelectronic center.     

Screening effect on polarizabilities of shallow donors and acceptors in infinite-barrier quantum wells

Polarizabilities of shallow donors and acceptors in infinite-barrier GaAs/Ga_1−xAl_xAs quantum wells have been calculated using the Hasse variational method within the effective mass approximation. The effect of spatially dependent screening on polarizabilities is taken into account with anr-dependent dielectric response. The effects of electric and magnetic fields are also presented.     

Polarizabilities of shallow donors in finite-barrier nanodots

Polarizabilities of shallow donors in finite-barrier GaAs/Ga_1−xAl_xAs of harmonic oscillator nanodots are calculated, within the effective-mass approximation, using the Hasse variational method. The magnetic field dependence of polarizabilities and the diamagnetic susceptibilities are computed.