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Crystalline and amorphous GaSb surfaces are compared concerning their response to sputter erosion with low energy Ar ϩ ions under normal incidence. We show that the formation of regular nanostructures on GaSb is basically independent of whether the initial material is crystalline or amorphous. The similarity in the temporal and spatial evolution demonstrates that the dynamics of the morphology evolution is entirely controlled by a thin amorphous surface layer. © 2002 American Institute of Physics. ͓DOI: 10.1063/1.1429750͔The large potential of nanoelectronics has stimulated much effort to find new methods for the parallel processing of nanostructures. Promising techniques, like StranskiKrastanov growth of semiconductor heterostructures 1 and self-assembly of semiconductor nanocrystals by colloid chemistry 2 have been exploited. Recently, during the erosion of semiconductor and metal surfaces by ion sputtering, a self-organizing mechanism has been discovered leading to regular patterns of structures with dimensions of some tens of nanometers.3,4 These surface structures can form quantum dots with a high aspect ratio and are therefore particularly attractive for quantum electronic applications.The appearance of periodic ripple patterns on semiconductor and metal surfaces bombarded with ions under offnormal incidence has been known for a long time. 5 In certain metals and III-V semiconductors these ripple patterns transform into hexagonally ordered isolated nanostructures under normal incidence sputtering. 3,4,6 -8 Up to now these observations have only been made in crystalline materials. The main points addressed in this letter concern ͑i͒ the comparison of the pattern evolution from initially crystalline ͑c-GaSb͒ and amorphous GaSb ͑␣-GaSb͒ targets and ͑ii͒ the microscopic structure of the patterned surface. We find that the surface dot patterns generated are independent of the crystallinity of the initial material surface. This independence is explained by the decisive role of a thin amorphous layer that forms during the very first seconds of the sputtering process. Besides the fundamental insight into the sputtering process on semiconductor surfaces, the structuring of amorphous layers deposited on arbitrary materials provides a technologically attractive method of surface nanostructuring.Stochastic nonlinear continuum models have been introduced to explain the temporal and spatial evolution of nanoscale surface patterns during ion sputteringwhere h(x,y) is the surface height function, v 0 is the constant erosion velocity, is the ''negative surface tension,'' ͑͒ is a nonlinear coefficient attributed to the tilt dependent sputter yield with the tilt angle, D is the thermal or ion induced surface diffusion, and denotes a noise term, that describes the stochastic character of the sputtering process. This continuum equation represents an approximation to the surface dynamics because higher order derivatives are not considered. The effect of additional higher order terms in Eq. ͑1͒ is believed to be minor. 10 The m...

A method for producing self‐organised arrays of nanometric metallic dots is reported. It consists on developing first the nanodot pattern by ion erosion on a semiconductor cover film and transferring it to a previously buried metallic layer. This procedure has been applied to Co, and the ferromagnetic behaviour of the dots at room temperature is demonstrated.

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