The role of ion flux in Si(100) nanostructuring by normal-incidence Ar+ ion sputtering has been studied. The measured relationships of the Si lateral dot size versus ion flux, the surface roughness versus ion flux, and the surface roughness versus sample temperature with ion fluxes of 20 and 380 /xA cm~(-2) all indicate that the value of the ion flux is decisive for the validity of the Bradley-Harper (BH) model in the nanostructuring of semiconductor single crystals. In this work, for Ar+ ion sputtering of Si(100) with ion energy of 1.5 keV, it is found that only beyond 220 fi A cm~(-2) is the BH model well applicable, while below that the Ehrlich-Schwoebel (ES) one tends to be involved. Our results suggest that the ES barrier effect is negligible under relatively high flux conditions, while it is substantial in the case of relatively low flux; for the BH model, the situation is just the reverse. Hence, caution should be exercised as regards the value of the ion flux when one tries to tune the semiconductor nanodot size following the BH model.
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机译：研究了离子流在通过正入射Ar +离子溅射进行的Si（100）纳米结构中的作用。在离子通量为20和380 / xA cm〜（-2）的条件下，Si侧点尺寸与离子通量，表面粗糙度与离子通量以及表面粗糙度与样品温度之间的测量关系均表明离子值通量对于Bradley-Harper（BH）模型在半导体单晶的纳米结构中的有效性起决定性作用。在这项工作中，对于离子能量为1.5keV的Si（100）的Ar +离子溅射，发现BH模型仅适用于超过220 fi A cm〜（-2），而低于Ehrlich-Schwoebel（ ES）人们往往会参与其中。我们的结果表明，在较高通量条件下，ES势垒效应可忽略不计，而在较低通量条件下则是相当大的。对于BH模型，情况恰好相反。因此，当尝试按照BH模型调整半导体纳米点尺寸时，应谨慎对待离子通量的值。
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