Delayering on Advanced Process Technologies using FIB
Delayering on Advanced Process Technologies using FIB
Thursday, November 13, 2014: 9:15 AM
310 A (George R. Brown Convention Center )
Summary:
The focused ion beam (FIB) offers a means to retain chip functionality whilst removing only localized regions during delayering. This is a great advantage, allowing further analysis (voltage contrast, defect analysis, electrical probing etc.) or circuit edit to be performed once the layer of interest has been reached. However, it is no easy task to delayer modern IC devices in the FIB due to the large number of different layers (with vastly differing milling rates) which are present. The complexity is compounded by the fact that multiple materials can exist together in a single layer, thus requiring what is called mixed field delayering. Difficulties arise when trying to delayer in mixed field regions with the bare FIB beam only and require using gas assisted etching (GAE) to achieve planar delayering.
The focused ion beam (FIB) offers a means to retain chip functionality whilst removing only localized regions during delayering. This is a great advantage, allowing further analysis (voltage contrast, defect analysis, electrical probing etc.) or circuit edit to be performed once the layer of interest has been reached. However, it is no easy task to delayer modern IC devices in the FIB due to the large number of different layers (with vastly differing milling rates) which are present. The complexity is compounded by the fact that multiple materials can exist together in a single layer, thus requiring what is called mixed field delayering. Difficulties arise when trying to delayer in mixed field regions with the bare FIB beam only and require using gas assisted etching (GAE) to achieve planar delayering.