scholarly journals Application of FIB/SEM and TEM to Bit Failure Analyses in SRAM Arrays

2003 ◽  
Vol 782 ◽  
Author(s):  
Wentao Qin ◽  
Alex Volinsky ◽  
Larry Rice ◽  
Lorraine Johnston ◽  
David Theodore

ABSTRACTMany microelectronic chips contain embedded memory arrays. A single SRAM bit-cell contains several transistors. Failure of any of the transistors makes the entire bit-cell inoperable. Dual-beam Focused Ion Beam (FIB) combines the slicing capability of FIB with in-situ SEM imaging. The combination offers unparalleled precision in looking for root causes of failures in microelectronic devices. Once a failure site is located, an FIB lift-off method can be used to prepare a TEM sample containing the area of interest. Further structural, elemental information can then be acquired from the failure site. We report here analyses of single and multiple bit failures in SRAM arrays carried out using FIB/SEM, and in two cases TEM imaging and EDS/PEELS. Root causes of bit failures including remnant seed-layer metal between stacked vias have been identified.

2021 ◽  
Author(s):  
Nadav Scher ◽  
Katya Rechav ◽  
Perrine Paul-Gilloteaux ◽  
Ori Avinoam

Imaging of cells and tissues has improved significantly over the last decade. Dual-beam instruments with a focused ion beam mounted on a scanning electron microscope (FIB-SEM), which offer high-resolution 3D imaging of large volumes and fields-of-view are becoming widely used in the life sciences. FIB-SEM has most recently been implemented on fully hydrated, cryo-immobilized, biological samples. However, correlative light and electron microscopy (CLEM) workflows combining cryo- fluorescence microscopy (cryo-FM) and FIB-SEM are not yet commonly available. Here, we demonstrate that fluorescently labeled lipid droplets can serve as in-situ fiducial markers for correlating cryo- FM and FIB-SEM datasets, and that this approach can be used to target the acquisition of large FIB-SEM stacks spanning tens of microns under cryogenic conditions. We also show that cryo-FIB-SEM imaging is particularly informative for questions related to organelle structure and inter-organellar contacts, nuclear organization and mineral deposits in cells.


Author(s):  
Jian-Shing Luo ◽  
Hsiu Ting Lee

Abstract Several methods are used to invert samples 180 deg in a dual beam focused ion beam (FIB) system for backside milling by a specific in-situ lift out system or stages. However, most of those methods occupied too much time on FIB systems or requires a specific in-situ lift out system. This paper provides a novel transmission electron microscopy (TEM) sample preparation method to eliminate the curtain effect completely by a combination of backside milling and sample dicing with low cost and less FIB time. The procedures of the TEM pre-thinned sample preparation method using a combination of sample dicing and backside milling are described step by step. From the analysis results, the method has applied successfully to eliminate the curtain effect of dual beam FIB TEM samples for both random and site specific addresses.


Author(s):  
Gunnar Zimmermann ◽  
Richard Chapman

Abstract Dual beam FIBSEM systems invite the use of innovative techniques to localize IC fails both electrically and physically. For electrical localization, we present a quick and reliable in-situ FIBSEM technique to deposit probe pads with very low parasitic leakage (Ipara < 4E-11A at 3V). The probe pads were Pt, deposited with ion beam assistance, on top of highly insulating SiOx, deposited with electron beam assistance. The buried plate (n-Band), p-well, wordline and bitline of a failing and a good 0.2 μm technology DRAM single cell were contacted. Both cells shared the same wordline for direct comparison of cell characteristics. Through this technique we electrically isolated the fail to a single cell by detecting leakage between the polysilicon wordline gate and the cell diffusion. For physical localization, we present a completely in-situ FIBSEM technique that combines ion milling, XeF2 staining and SEM imaging. With this technique, the electrically isolated fail was found to be a hole in the gate oxide at the bad cell.


2006 ◽  
Vol 983 ◽  
Author(s):  
Todd Simpson ◽  
Ian V Mitchell

AbstractAperture arrays were fabricated in 1.0µm thick gold films supported on 20nm thick silicon nitride membranes. Lithographic milling strategies in gold were evaluated through the use of in-situ sectioning and high resolution SEM imaging with the UWO CrossBeam FIB/SEM. A successful strategy for producing a 250nm diameter hole with sidewalls approaching vertical is summarized.


Author(s):  
Steven B. Herschbein ◽  
Hyoung H. Kang ◽  
Harvey E. Berman ◽  
Carmelo F. Scrudato ◽  
Aaron D. Shore ◽  
...  

Abstract The presence of a full wafer dual-beam FIB on the process floor gave rise to an environment in which formerly segregated off-line lab and FAB tasks could be linked. One such idea involved a methodology for semi-automated defect targeting based on the spatial predictions of static random access memory (SRAM) electrical testing. The embedded memory blocks on some processors are fully configured and probe pad testable as early as the forth metal level. Using a unique navigation technique that combines electrically sorted SRAM bit map data with CAD coordinate information and stage driven X-Y stepping, the FIB tool was used to locate, section and image prior level defects. We believe that with the inclusion of suitable fiducial markers in the chip design and advanced pattern recognition to aid navigation and guide depth milling, a fully automated process for electrical yield detractor diagnosis could be introduced.


Author(s):  
Chih-Chung Chang ◽  
Jian-Chang Lin ◽  
Wen-Sheng Wu ◽  
Chih-Ying Tasi ◽  
Ching-Lin Chang

Abstract A dual beam FIB (Focused Ion Beam) system which provides the ion beam (i-beam) and electron beam (e-beam) function are widely used in semiconductor manufacture for construction analysis and failure cause identification. Although FIB is useful for defect or structure inspection, sometimes, it is still difficult to diagnose the root cause via FIB e-beam image due to resolution limitation especially in products using nano meter scale processes. This restriction will deeply impact the FA analysts for worst site or real failure site judgment. The insufficient e-beam resolution can be overcome by advanced TEM (Transmission Electron Microscope) technology, but how can we know if this suspected failure site is a real killer or not when looking at the insufficient e-beam images inside a dual beam tool? Therefore, a novel technique of device measurement by using C-AFM (Conductive Atomic Force Microscope) or Nano-Probing system after cross-sectional (X-S) FIB inspection has been developed based on this requirement. This newly developed technology provides a good chance for the FA analysts to have a device characteristic study before TEM sample preparation. If there is any device characteristic shift by electrical measurement, the following TEM image should show a solid process abnormality with very high confidence. Oppositely, if no device characteristic shift can be measured, FIB milling is suggested to find the real fail site instead of trying TEM inspection directly.


Author(s):  
R.J. Young ◽  
A. Buxbaum ◽  
B. Peterson ◽  
R. Schampers

Abstract Scanning transmission electron microscopy with scanning electron microscopes (SEM-STEM) has become increasing used in both SEM and dual-beam focused ion beam (FIB)-SEM systems. This paper describes modeling undertaken to simulate the contrast seen in such images. Such modeling provides the ability to help understand and optimize imaging conditions and also support improved sample preparation techniques.


2012 ◽  
Vol 531-532 ◽  
pp. 592-595
Author(s):  
Yi Qing Chen ◽  
Feng Zai Tang ◽  
Liang Chi Zhang

This paper reports the specimen preparation using an advanced dual beam focused ion beam (FIB) technique for bulk polycrystalline diamond (PCD) composites after dynamic friction polishing (DFP). The technique adapted allows for precisely processing diamond materials at the specific polishing track sites of PCD surface, from which large cross-sectional specimens for SEM/EDS/Raman microanalysis could be successfully created. In addition, an in-situ lift-out method was developed to prepare the site-specific HRTEM specimens which were thin enough for imaging the atomic lattice of diamond and for conducting EELS analysis.


2020 ◽  
Vol 26 (2) ◽  
pp. 211-219
Author(s):  
Majid Ahmadi ◽  
Frans D. Tichelaar ◽  
Andreas Ihring ◽  
Michael Kunze ◽  
Sophie Billat ◽  
...  

AbstractIn microstructural corrosion studies, knowledge on the initiation of corrosion on an nm-scale is lacking. In situ transmission electron microscope (TEM) studies can elucidate where/how the corrosion starts, provided that the proper corrosive conditions are present during the investigation. In wet corrosion studies with liquid cell nanoreactors (NRs), the liquid along the electron beam direction leads to strong scattering and therefore image blurring. Thus, a quick liquid removal or thickness control of the liquid layer is preferred. This can be done by the use of a Peltier element embedded in an NR. As a prelude to such in situ work, we demonstrate the local wetting of a TEM sample, by creating a temperature decrease of 10 ± 2°C on the membrane of an NR with planar Sb/BiSb thermoelectric materials for the Peltier element. TEM samples were prepared and loaded in an NR using a dual-beam focused ion beam scanning electron microscope. A mixture of water vapor and carrier gas was passed through a chamber, which holds the micro-electromechanical system Peltier device and resulted in quick formation of a water layer/droplets on the sample. The TEM analysis after repeated corrosion of the same sample (ex situ studies) shows the onset and progression of O2 and H2S corrosion of the AA2024-T3 alloy and cold-rolled HCT980X steel lamellae.


Author(s):  
Richard J. Young ◽  
Michael P. Bernas ◽  
Mary V. Moore ◽  
Young-Chung Wang ◽  
Jay P. Jordan ◽  
...  

Abstract The dual-beam system, which combines a high-resolution scanning electron microscope (SEM) with a focused ion beam (FIB), allows sample preparation, imaging, and analysis to be accomplished in a single tool. This paper discusses how scanning transmission electron microscopy (STEM) with the electron beam enhances the analysis capabilities of the dualbeam. In particular, it shows how, using the combination of in-situ sample preparation and integrated SEM-STEM imaging, more failure analysis and characterization problems can be solved in the dual-beam without needing to use the Ångstrom-level capabilities of the transmission electron microscope (TEM).


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