(1) From the standpoint of the potential energy, the one-bond-type migration is divided into the BC (bond-centered type) and SP (split 〈1
0
0〉 type) migrations. In the BC migration, there are two ...kinds of atom migrations. One is that in which a BC atom pushes its neighboring atom to a BC site. This is the typical migration by the interstitialcy mechanism. The other is that in which a BC atom rotates about its neighboring atom and becomes the BC atom again. This is a feature of the BC migration. (2) The BC and SP migrations are applied to P diffusion in Si. Assuming there is no interaction between P and Si, the distance and probability for each step of the migration are obtained and applied to Si self-diffusion. Because they are not constant, the definition of the correlation factor for the self-diffusion is different from the usual one.
The bulk boundary condition for the numerical solution of the phosphorus diffusion
equation in silicon, which is based on the pair diffusion model of the vacancy mechanism, is
studied. The zero ...concentration-gradient condition of vacancy at a region more than two times
deeper than the phosphorus diffusion depth can be used in place of the equilibrium
concentration condition of vacancy at
x
=∞. The zero concentration-gradient condition is
applicable to diffusion equations based on the pair diffusion models of vacancy and
interstitialcy mechanisms.
The effects of melt-temperature fluctuations on growth striations in crystals grown in a commercial-scale growth system were studied by an analysis of the fast-Fourier-transform (FFT) method applied ...to the melt-temperature fluctuations and to the growth striations as evaluated by X-ray topography and spreading-resistance (SR) methods. The period of the growth striations observed in crystals corresponded exactly to that of temperature fluctuations in the melt; however, the amplitude of these growth striations decreased when temperature fluctuations with a constant amplitude occurred rapidly. This phenomenon results from a delay in the response of the microscopic growth rate to rapid temperature fluctuations. The amplitude of melt-temperature fluctuations and the peak height of the FFT power spectra were observed to decrease in the radial direction toward the crystal center, and this trend was also observed for growth striations. It was concluded that temporal thermal fluctuations caused by melt convection are preserved in growth striations for crystals grown in large growth systems.
The time variations of electron beam-induced currents through the Schottky contact on boron-doped p-type homoepitaxially grown diamond are analyzed in order to clarify the relationship between the ...decay in electron density and the hole emission at a boron acceptor level after removal of electron beam pulse. It is shown that the electron density varies with a time constant corresponding to the thermal emission rate of holes in the acceptor level, which means that electron beam-induced currents are dominated by the hole emission rate at the acceptor level.
The grown-in defects in Czochlalski silicon with various growth-striation intervals are investigated using the optical precipitate profiler and compared with the distribution of interstitial oxygen ...concentrations Oi. The striation intervals do not influence the density or size of the grown-in defects. However, the defect size in the peak Oi region is the same as the size in the valley Oi region and the total defect volume in the peak is larger than the volume in the valley. It is suggested that the grown-in defects grow by gathering vacancies into some nuclei in the peak region.
It is assumed that an interstitial phosphorus atom and a self-interstitial, P
i
and I,
are of the interstitialcy type. One bond-type migration is applied to their migration. It
is concluded that ...there is essentially no difference between the migrations of a P-I pair,
(PI), and P
i
by the interstitialcy mechanism and between the chemical processes for the
formation-dissociation of (PI) and the kick-out mechanism of P
i
.
Dopant and oxygen striations, and grown-in defect striations in Czochralski silicon crystals grown under long-period temperature fluctuations in the melt were measured at the exact same position in ...the crystal by spreading resistance measurement and an electron-beam-induced current method with Au diffusion, X-ray topography and micro-Fourier transform infrared spectroscopy, and an optical-precipitate-profiler (OPP) method, respectively. We observed that the rapid variations in dopant striations caused by remelting during crystal growth do not appear for oxygen striations. OPP defects were found to be distributed along the regions of the high oxygen concentration.
