Nanometer-scale columns in GaAs fabricated by angled chlorine ion-beam-assisted etching

Angled chlorine ion-beam-assisted etching has been used in combination with masked ion beam lithography to produce columns in GaAs with widths of less than 10 nm and height-to-width ratios greater than 25. This technique allows the highly controllable fabrication of structures with dimensions smaller than initially defined by the lithography. It can be applied to the fabrication of ultrasmall GaAs/AlGaAs quantum well structures having quantized energy states in two or three dimensions while at the same time being compatible with full-wafer processing.