Self-sustained etch masking: A general concept to initiate the formation of nanopatterns during ion erosion

A material allowing for rapid and reliable formation of nanopatterned surfaces is an important issue in many areas of science today. Self-organized pattern formation induced by ion erosion is a promising bottom-up approach. In the case of the III-V semiconductors, this method can lead to several remarkable structure types even if the formation mechanism has yet to be found. Through high resolution chemical scanning, transmission electron imaging, and x-ray photo emission, we show through an investigation of GaSb that the capacity of III-V semiconductors to pattern under ion erosion is linked to the phase diagram of these materials. We suggest an original scenario to explain the specific behavior of III-V semiconductors, where one species segregates and acts as a continuously resupplied etching shield. This concept is at variance with the standard Bradley-Harper model and opens interesting perspectives for bottom-up patterning of compound materials.