Phosphorus Donors In Silicon Research Articles

Hydrogen states probed by electron-spin resonance of phosphorus donors in silicon.

Hydrogen in phosphorus-doped silicon has been investigated, by monitoring shallow donor P by electron-spin resonance (ESR). Significant broadening in motionally narrowed ESR lines is first observed in Si samples treated with hydrogen plasma. It is found from the donor-concentration dependence that the broadening is caused by the Fermi-contact hyperfine interaction between hydrogen nuclear spins and donor or conduction electrons. Results of annealing hydrogen-passivated Si indicate that an intermediate state of hydrogen with a P donor neighbor is formed via dissociation of P-H complexes at 150--350 \ifmmode^\circ\else\textdegree\fi{}C, and that hydrogen diffuses in n-type Si above 350 \ifmmode^\circ\else\textdegree\fi{}C.

Linewidths of the electronic excitation spectra of donors in silicon

The excitation spectra of phosphorus, arsenic, isolated interstitial lithium, and lithium oxygen donors in silicon have been investigated under the high resolution of a Fourier-transform spectrometer. Using a "strain-free" mounting technique, the linewidths are observed to be much narrower than those reported earlier in the literature; the observed linewidths appear to be limited by the "lifetime" effects. The linewidths and shapes of the excitation lines of phosphorus donors in silicon, introduced by the nuclear transmutation of $^{30}\mathrm{Si}$ into $^{31}\mathrm{P}$ by the capture of a slow neutron followed by a ${\ensuremath{\beta}}^{\ensuremath{-}}$ decay, are studied; the influence of the charged defects produced by neutron irradiation is demonstrated and explained in terms of the electric fields due to charged impurities and defects.

A high resolution study of the excitation spectrum of phosphorus donors introduced in silicon by neutron transmutation

The electronic excitation spectrum of phosphorus donors in silicon generated by neutron transmutation has been observed. High resolution of a Fourier Transform spectrometer combined with “strain free” mounting technique revealed line widths much narrower than reported earlier. The line widths and shapes as affected by the presence of charged defects produced by the neutron irradiation were studied. An explanation for the observed line width and shape is proposed.

Impact excitation of phosphorus in silicon at low temperatures

Conduction electrons moving in moderate electric fields are used to promote electrons successively into the higher excited states of the phosphorus donor in silicon at low temperatures. The method of delayed breakdown is used: (i) to measure the threshold electric field at which a state may be excited and thus to help identify the state; and (ii) to measure the lifetime of that state. In the temperature range 17-20K it was found that the lifetime of one of the upper 1s states (T1 or E) was of the order of hours, that of one of the 2s states was of the order of tenths of seconds, and that of the other 2s state was of the order of seconds.

Exchange and dipolar fields in phosphorus-doped silicon measured by electron spin echoes

The instantaneous diffusion effect of Klauder and Anderson has been observed in electron spin echo measurements on phosphorus donors in silicon. Our results give the size and radial dependence of exchange and dipolar interactions between donors. Previous studies of the spin-packet width in this system are re-interpreted.