Damage formation and annealing studies of low energy ion implants ...

Figure 4.14 Illustration of the double alignment scattering configuration used in the MEIS
experiments, showing the shadowing and blocking.
Kinematic factor Depth resolution (nm)
[332] – 60.5° [111] – 70.5° [332] [111]
Au 0.9796 0.9732 0.42 0.50
Xe 0.9695 0.9602 0.43 0.51
Sb 0.9672 0.9571 0.43 0.51
As 0.9472 0.9312 0.43 0.52
Si 0.8643 0.8255 0.46 0.57
F 0.8059 0.7527 0.49 0.61
O 0.7731 0.7124 0.50 0.64
B 0.6789 0.5991 0.55 0.73
Table 4.1 Values of the kinematic factor for He ions using the [īīı] direction on the inward
path and the [332] and [111] directions on the outward path. The corresponding depth
resolutions are given for a 100 keV He.
To align the sample to the beam along a crystallographic direction, angular scans
across the three rotational axes to find the positions with the minimum scattering yield,
have to be performed in a systematic sequential manner.
The dose of the beam has to be chosen as a balance between achieving an
adequate signal to noise ratio, and acceptable data collection times of the allocated beam
time, so as to allow an adequate number of samples to be carried out. Beam damage to
the Si needs to be minimised and so the sample would be moved after a set amount of
beam on target, to a fresh spot. For most samples analysed, the current integrator was
set to acquire a dose corresponding to 5µC charge.
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