The examination of partially deprocessed ICs for well imaging has been investigated. First it has been shown [1] that Ga+ FIB imaging can readily and strongly highlight the N-well / P-well boundary in an IC as shown again here. Second, a model which only considers secondary electron creation and scattering [2] is confirmed to be sufficient for understanding these imaging effects. Heavy Ga doping provides no marked change in PVC (passive voltage contrast). Then comparisons in the same field of view between optimized He+ and Ga+ imaging, has shown that He+ provides much greater PVC contrast when looking through deep oxide, and much better resolution on shallow surfaces. The quantitative model Stopping and Range of Ions in Matter (SRIM) [3] was consulted and confirmed these expectations for resolution and depth superiority of the He+ beam. According to the SRIM, there may even be less damage from the He+ beam. Yet these known effects of Ga+ damage has not prevented its widespread use in semiconductor FA and process monitoring. Thus, the use of GFIS (Gas field ion source) He+ beam for voltage contrast and junction imaging warrants further exploration.

Nanomachining capability scaling both in the areas of machining precision and novel gas chemistries are required for focused ion beam technology to keep pace with process technology advancement. In this paper, we review the nanomachining potential for the Helium Ion Microscope (HIM) and the Neon Ion Microscope (NIM). The paper also includes an in depth analysis of NIM imaging resolution, subsurface material interaction, and nanomachining performance.

Currently, the helium ion microscope (HIM) can be operated in three imaging modes; ion induced secondary electron (SE) mode, Rutherford backscatter imaging (RBI) mode, and scanning transmission ion imaging (STIM) mode. This paper will provide an overview of microscope’s ion source, its ion optics, the system architecture, the fundamentals of these three imaging modes and many FA related examples. Recently integrated with the microscope are a Rutherford Backscatter (RBS) detector for materials analysis and a gas injection system (GIS) for material modification. We will describe this new hardware and suggest how these additions could also contribute to the helium ion microscope being an important failure analysis tool.