An infrared and neutron scattering analysis of the precipitation of oxygen in dislocation-free silicon

Abstract

The precipitation of oxygen in silicon has been studied in the temperature range 650 to 1050 degrees C using the techniques of chemical etching, IR absorption applied to the 9 mu m band (4.2K), and small-angle neutron scattering (SANS). The IR data and etch pit counts, relating to the number densities of precipitate particles, have been fitted to Ham's theoretical model for the diffusion limited growth of randomly distributed particles. Full allowance is made for the increase in size of the precipitates with increasing time and good agreement is found over the complete period starting from zero time. Values of the diffusion coefficient of oxygen so determined are in excellent agreement with other data obtained by different methods, including SANS measurements at 750 degrees C described in the present work. The combined data give D=0.11 exp(-2.51 eV/kT) cm2s-1. The SANS data also indicate that the precipitates are not spherical in shape after a short initial period, and they show that the initial concentration of particles nucleated decreases with annealing time. The solid solubility cs(T) is determined at each temperature and compared with previous measurements. The authors conclude that the best combination of results leads to cs(T)=2.6*1022 exp(-1.4 eV/kT) down to 850 degrees C. At lower temperatures cs decreases more slowly with decreasing temperature, indicating a possible change in the structure or the form of the precipitated SiO2 phase.

Quantitative copper measurement in oxidized p-type silicon wafers using microwave photoconductivity decay

“…The radius of the oxide precipitates after the growth anneal can be estimated to be in the order of 3 nm. 8 The density of oxide precipitates after 4 h and 16 h nucleation is approximately 5 ϫ 10 8 and 10 10 cm −3 , respectively. 9 In the remainder of the letter, we will refer to these wafer groups as "homogenized", "low BMD", and "high BMD" wafers.…”

IR studies of the oxygen and carbon precipitation processes in electron irradiated tin-doped silicon

“…One of the conclusions of this analysis was that the total free energy F of a spheroidal oxide precipitate depends on the aspect ratio α, namely the ratio of the smaller half axis c to the larger half axis a of the structure. Additionally, it was determined [81,82] that the higher the annealing temperature (or the longer the annealing time, in the case of isochronal anneals) the larger the radius R of the precipitate and consequently the larger the pressure P of the structure. Figure 1a-d in Ref.…”

Integral Diffractometry of Nanoscale Defects in an Elastically-Bent Single Crystal

“…Это объясняется тем, что, при учете влияния УД согласно модели, предложенной автора-ми настоящей работы в работе [23], при ||   k фактор эффективного поглощения для когерентной составляющей ПИОС становится рав-ным фактору эффективного поглощения для диффузной составляю-щей ПИОС: exp( ds t)  exp( [26] соответствует температуре отжига 896С. Известно, что при температуре отжига ниже 900С не происходит образование больших дислокационных петель, радиус которых превышает радиус выдавливающих их кластеров.…”