•A dynamic Binary Collision Approximation algorithm is used to simulate the Focused Ion Beam milling process on silicon.•Point defect density is used in the dynamic algorithm to estimate the silicon ...amorphization layer thickness.•Experiments are designed to validate the simulation results with Transmission Electron Microscopy analysis.•Agreement between simulations and experiments suggests that such model can predict the FIB induced Si amorphization.
A Ga focused ion beam (FIB) is often used in transmission electron microscopy (TEM) analysis sample preparation. In case of a crystalline Si sample, an amorphous near-surface layer is formed by the FIB process. In order to optimize the FIB recipe by minimizing the amorphization, it is important to predict the amorphous layer thickness from simulation. Molecular Dynamics (MD) simulation has been used to describe the amorphization, however, it is limited by computational power for a realistic FIB process simulation. On the other hand, Binary Collision Approximation (BCA) simulation is able and has been used to simulate ion-solid interaction process at a realistic scale. In this study, a Point Defect Density approach is introduced to a dynamic BCA simulation, considering dynamic ion-solid interactions. We used this method to predict the c-Si amorphization caused by FIB milling on Si. To validate the method, dedicated TEM studies are performed. It shows that the amorphous layer thickness predicted by the numerical simulation is consistent with the experimental data. In summary, the thickness of the near-surface Si amorphization layer caused by FIB milling can be well predicted using the Point Defect Density approach within the dynamic BCA model.
Recent time-of-flight secondary ion mass spectrometry studies using primary ion cluster sources such as Au
n
+, SF
5
+, Bi
n
+ or C
60
+ have shown the great advantages in terms of secondary ion ...yield enhancement and ion formation efficiency of polyatomic ion sources as compared to monoatomic ion sources like the commonly used Ga
+.
In this work, the effective gains provided by such a source in the static ToF-SIMS analysis of microelectronics devices were investigated. Firstly, the influence of the number of atoms in the primary cluster ion on secondary ion formation was studied for physically adsorbed di-isononyl phthalate (DNP) (plasticizer) and perfluoropolyether (PFPE). A drastic increase in secondary ion formation efficiency and a much lower detection limit were observed when using a polyatomic primary ion. Moreover, the yield of the higher mass species was much enhanced indicating a lower degree of fragmentation that can be explained by the fact that the primary ion energy is spread out more widely, or that there is a lower energy per incoming ion.
Secondly, the influence of the number of Bi atoms in the Bi
n
primary ion on the information depth was studied using reference thermally grown silicon oxide samples. The information depth provided by a Bi
n
cluster was shown to be lowered when the number of atoms in the aggregate was increased.
Reliability and yield of nano-electronic devices can be seriously affected by the presence of surface contamination, even at low concentration. The microelectronics industry is, thus, in need for a ...quantitative, highly sensitive surface analysis technique capable of detecting both elementary and molecular species present at the surface. Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) provides a submicronic lateral resolution and excellent sensitivity with high secondary ion yields on a broad mass range but, nevertheless, remains a qualitative technique.
To convert normalized ion intensities into concentrations and, thus, to provide reliable quantification, the so-called relative sensitivity factors (RSFs) need to be determined. In earlier studies, ToF-SIMS RSFs for trace metals were determined from the calibration of ToF-SIMS positive ion intensities against quantitative analysis techniques able to determine a surface coverage such as vapour phase decomposition inductively coupled plasma mass spectrometry (VPD-ICP-MS) or total reflection X-ray fluorescence (TXRF) results.
Here, the aim is to quantify elementary anionic minority species (S, Cl, P, Br). Deliberately contaminated samples were prepared and analyzed with ToF-SIMS and several quantitative surface analytical techniques like TXRF, liquid phase extraction ionic chromatography (LPE-IC) or VPD-ICP-MS. None of these latter techniques can by itself successfully handle all the anionic species cases and ToF-SIMS turns out to be the more versatile and precise characterization technique in this context.
An epitaxial Si grown multi-layer stack consisting of boron delta-doped layers separated by 6.4
nm thick undoped films has been profiled using a Cameca IMS Wf magnetic SIMS. Using low energy oblique ...O
2
+ beam, the boron depth resolution is improved from 1.66
nm/decade at 500
eV down to 0.83
nm/decade at 150
eV. At very low impact energy O
2
+ bombardment induces a near full oxidation of silicon and oxygen flooding is then no more needed in the analytical chamber to get a smooth sputtering of silicon at 45° incidence angle.
In this communication, we used a modern analytical TEM–STEM fully equipped to carry out a complete physical and chemical study of Al/Ti/W/TiN interconnection evolution after 450
°C annealing. Using ...energy filtered TEM, compositional mapping, scanning TEM (STEM) Z contrast imaging, EDX and EELS spectrum imaging and micro-diffraction, we evidence at the Al/W top contacts interface a reaction between Al and W leading to the growth of Al
x
W inclusions inside the Al grains.
Due to relentless down scaling of device geometries, failure analysis is getting more and more complex. As a matter of fact, the success rate of Thermal Laser Stimulation (TLS) techniques drops ...significantly for 90/65 nm CMOS devices because of the lack of x, y and z accuracy. In our aim to improve the TLS based fault isolation method, we have studied thermal time-constant signatures using a Modulated Optical Beam Induced Resistance Change (MOBIRCH) technique that may provide accurate x and y submicron resolution as well as depth or z-information of defects in the interconnection part of devices. Both Modeling and measurement results indicate that OBIRCH signal phase shifts and heat-up & cool-down time constants indeed do correlate with the location, dimensions and density of the structures studied.
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