Deep sub micrometer imaging of defects in copper pillars by X-ray tomography in a SEM

D Laloum; F Lorut; J Bertheau; G Audoit; P Bleuet

doi:10.1016/j.micron.2013.10.014

Deep sub micrometer imaging of defects in copper pillars by X-ray tomography in a SEM

Micron. 2014 Mar:58:1-8. doi: 10.1016/j.micron.2013.10.014. Epub 2013 Nov 5.

Authors

D Laloum¹, F Lorut², J Bertheau³, G Audoit⁴, P Bleuet⁴

Affiliations

¹ STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles, France; CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France. Electronic address: david.laloum@cea.fr.
² STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles, France.
³ STMicroelectronics, 850 rue Jean Monnet, 38926 Crolles, France; CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France.
⁴ CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9, France.

PMID: 24316374
DOI: 10.1016/j.micron.2013.10.014

Abstract

The potential of X-ray nanotomography hosted in a SEM in presented in this paper. In order to improve the detail detectability of this system, which is directly related to the X-ray source size, thin metal layers have been studied and installed in the equipment. A 3D resolution pattern has been created in order to determine the smallest detectable features by this setup. This sample is a 25 μm diameter copper pillar in which size-controlled holes have been milled using a plasma-focused ion beam. This pattern has then been scanned and the resulting 3D reconstruction demonstrates that the instrument is able to detect 500 nm diameter voids in a copper interconnection, as used in 3D integration.

Keywords: 3D integration; Copper pillar; Nanotomography; Plasma FIB; SEM; X-ray.

Publication types

Research Support, Non-U.S. Gov't