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Our intent in this investigation was to explore the effects of steps in the silicon surface on hydrogen desorption. Seeing that the A-step base was a preferential desorption site is indeed an important results. Unfortunately, B-step base shows no such signs of preferential desorption. However, [11] surmises that both types of step edges provide for preferential desorption sites. Why are our results different from their experimental theory?
We think that this is due to the nature of the problem considered. We examined only straight B-steps. However, in nature, B-steps are never straight. They tend to be very jagged, yielding large number of tiny A-steps on their sides. Since we have shown that A-steps are preferential diffusion sites, it is quite possible that these effects might be what lead to the theory of preferential desorption advanced in [11].
Extension of our current code to deal with jagged B-steps would require only changes to the surface routines (surface.cc), and and would be only mildly challenging. If this work is to progress, this would be the next logical area to investigate.
Also, investigation into ``better'' activation energies that yield to a better fit to analytic results in the 800K-900K temperature range would be of interest. Since all experimental activation energies come with error bars, it is quite likely that tweaking the values used in the simulation within those ranges could yield more physical results.
Finally, looking at longer time runs at higher temperatures might yield the effects of the ``denuded zone'' near the step edges (an area with a significantly lower H atom concentration) as theorized in [11].