Authors: M. Halbwax, T. Sarnet, J. Hermann, Ph. Delaporte, M. Sentis, L. Fares and G. Haller
Affilation: LP3 UMR CNRS 6182, France
Pages: 438 - 441
Keywords: femtosecond laser, dual beam FIB, defect analysis, Ion beam
The detection and analysis of defects in Integrated Circuits (IC) are major challenges faced by the semiconductor industry as outlined by the roadmap in the latest International Technology Roadmap for Semiconductors (ITRS). Advanced tools used today for defect cross sectioning include dual beams (focused ion- and electron-beam technologies) with resolution down to the sub-Angstrom level. However ion milling an IC with a FIB is time consuming because of the need do produce first wide opened cavities in front of the cross-sections that need to be analyzed. Therefore the use of a femtosecond laser as a tool for direct material removal is discussed in this paper. Experiments were performed on IC structures to reveal the different layers of fabrication: depending on the laser energy density selective or total ablation of the materials can occur, without delamination of the layers. Different laser irradiation conditions like pressure (air, vacuum..), polarization and beam shaping, scanning parameters have been used to produce different types of cavities. The femtosecond laser engraving of silicon-based structures could be useful for cross-sectioning of devices but also for other applications like direct-write lithography, photomask repair, maskless implantation or reverse engineering/restructuring.