Infrared studies of isothermal annealing of ion-implanted silicon: Refractive indices, regrowth rates, and carrier profiles

Abstract

A model-dependent computer analysis technique developed previously has in this work been applied to the infrared reflection data of a number of < 111 > and < 100> oriented Si samples which were implanted with high fluences ofSi or P ions and then taken through an isothermal annealing process. The physical properties deduced from this analysis are: (i) Dielectric properties including the frequency dependent refractive indices of the recrystallized Si and of the a-Si as a function of annealing temperature and time; (ii) structural information including the amorphous layer depth, widths of transition regions, and the epitaxial regrowth rates; and (iii) electrical properties including the depth profile of the carrier density, the carrier mobility near the maximum carrier density, and the carrier activation efficiency. The physical interpretation ofthe results is discussed and, where possible, comparisons with results of other experiments are made.

Double SIMOX Structures Formed by Sequential High Energy Oxygen Implantation into Silicon

“…To find the values for these constants a typical FTIR reflectance spectrum from an ␣-Si layer (produced by Si implantation at 1 MeV) on top of a Si substrate, was fitted. The best fit values found were: A ␣ ϭ 7.04 Ϯ 0.02, B ␣ ϭ 2.65 ϫ 10 9 Ϯ 5 ϫ 10 7 cm Ϫ2 , and ⍀ ␣ ϭ 18865 Ϯ 5 cm Ϫ1 , which are in good agreement with values reported by Waddell et al 22 In this work ␣-Si was produced by ion implantation of oxygen into Si and we therefore expect to encounter only this state.…”

Depth dependent modification of optical constants arising from H+ implantation in n-type 4H-SiC measured using coherent acoustic phonons

“…For example, several studies report increased refractive index arising from ion implantation in diamond, 21,[28][29][30][31] silicon, [32][33][34][35] and germanium, 36 despite considerable volume expansion. In all cases, the increase is attributed to a change in the atomic bond polarizability.…”

Exponential absorption edge and implantation-induced modifications in amorphous gallium arsenide

“…The same ®nding was established for the amorphous Si (Ivanda et al 1995). It is worth noting that the existence of two optically distinct amorphous states has been proposed in ion-implanted Si, GaAs and Ge a long time ago (Waddell et al 1982, Kwun et al 1985, Wang et al 1985; however, that concept did not gain much support since most of the experimental methods cannot di erentiate between the two states.…”

“…They attributed this surprising result to a`network reorganization' within the amorphous phase, which is then re¯ected in speci®c alterations in the refraction index, absorption, density of electronic spins in dangling bonds, etc. The equivalent results have been obtained for Si and Ge (Waddell et al 1982, Wang et al 1985 which implies that the ®nding is not material-speci®c. In addition, in their study of the in¯uence of gradual ordering on the optical properties of thin GaAs ®lms, Baker et al (1993) detected a decrease in the slope of the absorption edge (indicating disorder) in samples in which, on the other hand, a higher degree of order was found by extended X-ray absorption ®ne structure, X-ray photoelectron spectroscopy and transmission electron microscopy (TEM).…”