Quantum device microfabrication: Resolution limits of ion beam patterning

摘要

We have achieved precise control of the lateral electrical damage accompanying ion beam patterning of submicron electron devices from semiconductor materials.Insitutransport measurements, made in the etching chamber during the definition process, provide an exact and reproducible means of endhyphen;point detection, irrespective of material structure and ion beam parameters. We apply this to routinely fabricate conducting channels having widths below 100 nm from highhyphen;mobility GaAs/AlGaAs heterojunctions. Subsequent lowhyphen;temperature magnetotransport measurements and successive optimization of processing conditions enable us to systematically obtain the minimum conducting width. Through these studies we explore the ultimate resolution limits of the ion beam patterning process.