High resolution 3D imaging of integrated circuits by x-ray ptychography

Abstract

Significant advances in lithography and chip manufacturing in recent years have resulted in new challenges in metrology of electronic microdevices. Manufacturing process for the 10 nm node is already available and in combination with complex three-dimensional structured interconnections, there is a lack of methods for verification that the final products correspond to the original specifications. X-ray ptycho-tomography is a locally nondestructive imaging method that could potentially help to fill the gap between electron microscopy and conventional X-ray tomography. Quantitativeness of ptycho-tomography provides detailed device geometries and corresponding sensitivity to elemental composition through the complex-valued refractive index. In order to tackle the experimental challenges and improve the imaging quality, new computational methods need to be developed for both ptychography and tomography that can account for a wide range of imperfections such as sample drifts, illumination changes or sample changes during the scan. Here, we will mention the most important of them and possible ways how to deal with them.