Shave-off Profiling Research Articles

Study on Sputtering Mechanism of Shave-off Profiling

Shave-off profiling with nano-beam SIMS achieves the highly precise depth profiling with nanometer-scaled depth resolution by utilizing FIB micro-machining process to provide depth profile. This method is very unique depth profiling for acquiring a depth profile by shave-off scanning mode (A fast horizontal sweep of FIB is combined with the very slow vertical sweep). Shave-off profiling has its own features; absolute depth scale, pin point depth profiling and application for rough surface and/or hetero interface. However, the discussion of the sputtering mechanism in shave-off profiling is still insufficient because shave-off scanning mode has distinctive position of the primary ion beam against the sample. In this study, we discussed the difference of sputtering mechanism between shave-off scan and conventional raster scan from the view point of sputtered atom yields of experimental results and calculation results. In addition, the molecular dynamics (MD) simulation under shave-off condition is improved in order to visualize the sputtering mechanism of shave-off profiling. As a result,‘shave-off sputtered atom yield’is rather high compared to conventional sputtered atom yield according to distinctive sputtering mechanism of shave-off scanning mode. [DOI: 10.1380/ejssnt.2011.386]

Improvement and evaluation of the nano-beam SIMS control system

Shave-off depth profiling with nano-beam SIMS, our own technique, achieves the highly precise depth profiling with nanometer-scale depth resolution by utilizing a Focused Ion Beam (FIB) micro-machining process to provide the depth profile. This method is to acquire depth profiling by the shave-off scanning mode. However, we could obtain the signals as a function of time because the FIB scanning system and the signal acquisition system were working independently. Therefore, we developed a new system to obtain the signals as a function of two-dimensional position of the FIB. As a result, we could divide a shave-off profile up to 256 along lateral direction. We defined these lateral areas “lanes” and named this new method “multilane shave-off profiling”.

Multilane shave-off profiling for build-up circuit

Shave-off depth profiling by nano-beam secondary ion mass spectrometer (nano-beam SIMS), our own unique technique, achieves the highly precise depth profiling with nanometer-dimensional depth resolution. This method is a very unique depth profiling for acquiring a depth profile by the shave-off scanning mode (a fast horizontal sweep of an FIB is combined with a very slow vertical sweep). Shave-off depth profiling has its own features: absolute depth scale, pin point depth profiling and application for rough surface and hetero interface. However, conventional shave-off depth profiling provided only depth information by integrating lateral information. Therefore, we newly developed multilane shave-off profiling. In this new method, we can divide some lateral information precisely by synchronizing signal acquisition with FIB control. In this study, we demonstrate the example of new multilane shave-off profiling by analyzing build-up circuit.

Shave-off vector profiling for TEM samples

This study aims to cross-check the same sample, the same part and the same piece by shave-off profiling and scanning transmission electron microscope (STEM) imaging. For cross-check analysis, a piece was picked up from a failed IC package which might cause electrochemical migration. Critical disagreement on each result was gradient curve on shave-off depth profiling from anode to cathode. In the same piece, shave-off profiling visualized a faint gradient of migrated ions which could not be observed by STEM imaging.

Shave-off depth profiling: Depth profiling with an absolute depth scale

Shave-off depth profiling provides profiling with an absolute depth scale. This method uses a focused ion beam (FIB) micro-machining process to provide the depth profile. We show that the shave-off depth profile of a particle reflected the spherical shape of the sample and signal intensities had no relationship to the depth. Through the introduction of FIB micro-sampling, the shave-off depth profiling of a dynamic random access memory (DRAM) tip was carried out. The shave-off profile agreed with a blue print from the manufacturing process. Finally, shave-off depth profiling is discussed with respect to resolutions and future directions.