Accuracy of pulsed laser atom probe tomography for compound semiconductor analysis

Abstract

Atom probe tomography has recently experienced a renaissance, strongly promoted by the revival of pulsed laser atom probe. The technique is now widely employed to study semiconductor materials at the nanometre level. This paper summarises some aspects of the accuracy of pulsed laser atom probe relevant to semiconductor applications. It is shown that laser pulsing can reduce the lateral resolution due to thermally stimulated surface migration. Moreover, the commonly observed cluster ions can undergo field dissociation which results in an increased probability of ion loss due to pile-up effects at the detector. Field dissociation can also induce a new type of local magnification that increases spatial inaccuracy in the data reconstruction. These effects can be reduced by an appropriate choice of experimental parameters. Despite these difficulties, the atom probe technique can provide unparalleled insight into the nanoscale structure and chemistry of a wide range of semiconductor devices.