Search Results for TEM samples

Scanning TEM electron beam-induced current (STEM EBIC) imaging is a promising technique for providing high-resolution electronic and thermal contrast as a complement to TEM’s physical contrast. This article presents recent progress in using the focused ion beam (FIB) to prepare thin, electrically contacted cross-section samples for STEM EBIC imaging and in situ biasing. Techniques involving both standard Ga+ FIB and Xe+ plasma FIB (PFIB) are described.

This article discusses the practice of FIB-based in situ lift-out, a sample preparation method that has proven particularly useful for failure analysis. It explains how samples are now being made for a wide range of TEM techniques, including holography, tomography, high-angle annular dark-field scanning, and electron energy-loss spectroscopy. In most cases, achieving optimal quality requires the use of alternate FIB milling angles, as in plan-view, sideways, and backside milling, all of which are discussed.

This article describes a sample preparation technique by which specific areas on integrated circuits can be manually polished to TEM transparency. The technique, called tripod polishing or the wedge method, produces cross-section samples within a few hours that require little or no additional thinning for TEM analysis. The method can also be used to prepare plan view TEM samples as well as samples for SEM analysis and light microscopy.

A new and improved sample preparation technique was developed by Wang. This technique uses an FIB instrument for the 90° rotation of a small portion of the specimen on the original grid by taking advantage of static force. All sample preparation steps, including thin-section creation and sample tilting, can be accomplished in a single process. The procedure is monitored in a high-resolution FIB instrument to assure a 100% success rate. Figure 1 shows a scanning electron microscope image of a 3D TEM sample with two rotated sections. The original TEM sample is a lift-out sample laid on carbon film.

Off-axis electron holography is a TEM-based imaging technique that reveals dopant anomalies and junction profiles in semiconductor devices. This article explains how the method works and how it is being used to visualize transistor source-drain regions, diffusion-related defects, and other features of interest in TEM samples. It also discusses related challenges and compares off-axis electron holography with other profiling techniques, particularly junction staining.

This article discusses sample preparation challenges that have impeded progress in producing bias-enabled TEM samples from electronic components, as well as strategies to mitigate these issues.

Shortcuts in failure analysis are sometimes to save time or money or because equipment or expertise is unavailable. This article presents simple but effective solutions in four areas, including deprocessing, FIB milling, microcleaving, and TEM sample preparation, that may help analysts work through or around such situations.

Long-term stability studies indicate that cathode degradation is one of the main failure mechanisms in anode-supported SOFCs. In order to better understand the microstructural degradation mechanisms of the cathode and the influence of oxygen partial pressure at relevant operating temperatures, the authors of this article acquired TEM samples from technological cells to study cation interdiffusion mechanisms and LSM-YSZ interactions, particularly in areas where LSM grains are in contact with YSZ electrolyte. Here they present and interpret the results.

This article describes an automated sample preparation process for SEM and TEM analysis based on submicron polishing. The method uses robotics, image processing, and a polishing wheel under computer control for a fully automated recipe-driven process that creates exact cross-sections with 0.1 μm accuracy.

This Master FA Technique column describes an easy and inexpensive solution to the problem of preparing TEM cross-sectional samples from etched wafers with large aspect ratio vias.

Localizing defects in one-of-a-kind failures can take days, weeks, or even months, after which a detailed physical analysis is conducted to determine the root cause. TEM and STEM play complimentary roles in this process; TEM because of its superior spatial resolution and STEM because it produces images that are easier to interpret and is less susceptible to chromatic aberrations that can occur in thicker samples. In the past, the use of STEM in FA has been limited due to the time required to switch between imaging modes, but with the emergence of TEM/STEM microscopes with computer controlled lenses, the use of STEM is increasing. This article provides an overview of STEM techniques and present examples showing how it is used to characterize subtle and complex defects in ICs.

Sample preparation is a critical step for dopant profiling of FinFET devices, especially when targeting individual fins. This article describes a sample-preparation technique based on low-energy, shallow-angle ion milling and shows how it minimizes surface amorphization and improves scanning capacitance microscopy (SCM) signals representative of local active dopant concentration.

Recent developments in automated image acquisition and metrology using transmission electron microscopy (TEM) and scanning transmission electron microscopy (STEM) have significantly improved the speed, precision, and usability of these techniques for controlling advanced semiconductor device manufacturing processes. As device dimensions have continued to shrink, these techniques may be needed to replace scanning electron microscopy (SEM) for the smallest critical dimension (CD) measurements. This article describes the use of automated S/TEM in a high-throughput CD-metrology workflow to support process development and control and explains how automated sample-preparation, data-acquisition, and metrology tools increase both throughput and data quality.

This is the story of how the mainstream Omniprobe FIB lift-out solution was invented and delivered to the market.

FIB milling is difficult if not impossible with III-V compound semiconductors and certain interconnect metals because the materials do not react well with the gallium used in most FIB systems. This article discusses the nature of the problem and explains how cryogenic FIB-SEM techniques provide a solution. It describes the basic setup of a FIB-SEM system and provides examples of its use on InN nanocrystals, GaN films, and copper-containing multilayer photovoltaic materials.

This article describes two innovative methods that can significantly improve the resolution of SEM imaging: scanning transmission electron microscopy in a scanning electron microscope (STEM-in-SEM) and forward-scattered electron imaging (FSEI). Both methods can be implemented in any SEM using special sample holders. No other modifications are required. Test results presented in the article show that 1 to 2 nm resolution is possible in thin sections, uncoated polysilicon gates, and photoresist.

Packaging integration continues to increase in complexity, driving more samples into FA labs for development support and analysis. For many of the jobs, there is also a need for larger removal volumes, compounding the demand for tool time and throughput. Focused ion beam (FIB) and dual-beam FIB/SEM systems are helping to relieve the pressure with their ability to create site-specific cross sections and to facilitate gate-level circuit rewire and debug. This article reviews the impact of packaging trends on failure analysis along with recent improvements in FIB technology. It also presents examples that illustrate how these new FIB techniques are being applied to solve emerging packaging challenges.

The sixth FIB-SEM workshop was held March 1, 2013, in Cambridge, Mass. This article provides a summary of the event along with highlights from the 18 paper presentations.

The ability to discern the composition and placement of atoms in a sample makes TEM one of the most powerful characterization tools for microelectronic components. For many devices, however, the dynamics underlying normal operation do not displace atoms. Device function is, instead, mediated by electronic and thermal processes that have little effect on physical structure, necessitating additional tools to determine the causes of failure. In this article, the author presents results indicating that STEM EBIC, with the new SEEBIC mode, can provide electronic contrast that complements the physical-based contrast of STEM imaging. By identifying device features at higher risk of failure, the two methods may open a path to predictive failure analysis.

With the introduction of 65 nm technology, the cross-sectional dimensions of copper interconnect in some layers are now smaller than 100 nm, which translates to current densities on the order of several MA/cm2. Electromigration as a root cause for chip failure is thus a major concern and is still being examined. In this article, the authors present recent failure analysis studies on metal-coated copper interconnects, using OBIRCH techniques in combination with FIB cross-sectioning and SEM and TEM imaging.