X-ray production range in solids by 2-15 keV electrons

Abstract

A modified equation is proposed for the X-ray production range of 2-15 keV electrons in solids. The modification is obtained by an experimental procedure which compares the difference in X-ray intensities between pure element thin films and 'bulk' standards. The elements evaluated were Al, Ti, Ni, Zr, Nb, Mo, Pd, Ta and Pt. Monte Carlo simulations were made for several of the elements and agree with experimental results to within 5%. There was one exception, in the case of a high-atomic-number film (Pt on Si) at low keVs. Here the deviation increases to 10-20%. The modified equation is also compared to other range equations in the literature.

IntriX: a numerical model for electron probe analysis at high depth resolution. Part II—tests and confrontation with experiments

“…Variation of the total ionization mass depth in a rz 99 † silver matrix at keV as a function of the incident overvol-E 0 ¼ 3.8 tage : comparison between the empirical fit established by Legrand24 at 3.8 keV, the general empirical fit by Reuter et al .20 and the results computed with IntriX. scattering e †ects.1 A relevant test is obtained from the data of Reuter et al20 concerning the Pt Ma emission in Pt Ðlms of equal thickness deposited on two drastically di †erent substrates, Si and Au. As can be seen inFig.…”

Maximum depth of characteristic X-ray generation

“…Some discrepancies are obtained in the energy range below 5 keV. For this range the mean deviation with Reuter's equation ( [3] and Table 1) is not changed (about 12%), buth the deviation from (6) increases to 38%. It must be remarked that in the present work for an estimation of the paranieters a, n, and 6 of (1) only p o .…”

“…This procedure is more practical, because experiniental values have been obtained using targets with a thickness of approximately 95 to 98% of the maximum X-ray production thickness, e.g. in [3].…”

The influence of elastic and ionization cross‐section approximations on the result of Monte Carlo calculations

“…With the help of this program we investigated the x-ray depth distribution in a set of systems of film-substrate type. Figure 1 shows the calculated and experimental values (Reuter et al 1978) of the K-ratio for the aluminum films of different thicknesses on silicon versus the electron energy. It becomes obvious that the Monte Carlo results are larger than the experimental results.…”