In this interview, AZoNano discusses the Unity - BEX imaging technique with Haithem Mansour and explores the features of Unity that make it the ultimate in SEM imaging technology.
Could you provide an overview of the BEX technology and how it works?
Backscattered electron and X-ray imaging (BEX) is a novel imaging technique in scanning electron microscopes (SEM). This method offers an instant colored image within the SEM, integrating elemental information and topographical features under standard imaging conditions.
While navigating around the sample, the user is presented with a colored image detailing which elements are present and where. For the first time, a detector combining two types of sensors, backscattered electron and X-Ray, is placed below the polepiece to enable this innovative imaging approach.
How does the BEX technique differ from existing techniques in the field?
Imaging in the SEM has always been black and white, primarily utilizing two signals: secondary electrons and backscattered electrons. Consequently, the resulting image is monochromatic.
Secondary electrons provide information about the topography, while backscattered electrons offer indicative data about z-atomic number.
Users traditionally relying on these two imaging techniques must use their instincts to locate likely areas of interest or concern.
On the other hand, the BEX technique instantly displays all the elements present, eliminating the need to rely on instinct and potentially spend significant time searching for, for example, a contaminant or a specific phase.
With the BEX technique, users can enjoy a colored image comprising elemental and topographical information. This allows them to promptly identify the elements present and significantly expedite their search for specific targets.
How does the BEX technique help to address some of the limitations or challenges associated with traditional imaging technologies?
Traditionally, users had to go through a sequential process to conduct analysis. Using a black-and-white image, they attempted to locate their area of interest, whether a specific phase, contamination, or area. After identifying a likely area, they had to change their beam and experimental conditions to suit the analysis, such as by using EDS.
This involved increasing the beam current, acquiring an image, and obtaining an EDS spectrum or map to confirm the correct area of interest. If what was sought wasn’t there, the search had to begin over again. This repetitive process is known as the "loop of suffering" in electron microscopy, as people must frequently repeat it several times before they find what they are looking for.
However, with BEX, the loop of suffering is eliminated. Users now have all the necessary information in real time, and the need to switch between imaging and analytical conditions or increase the beam current is also removed.
Video Credit: Oxford Instruments NanoAnalysis
BEX is an imaging technique used under normal imaging conditions, providing all the information the users require in real time. This results in faster and more efficient identification of the area of interest, contaminants, or phases, saving time and preventing users from overlooking important sample features.
How does the BEX technology integrate or leverage advancements in nano-technology to enhance its functionality and performance?
SEM analysis is time-consuming, meaning often only a fraction of the sample can be analyzed. However, with this detector's high throughput, it enables a new mode, called Cartography, which allows the entire sample to be imaged quickly, changing how people work and opening the door to new applications.
Video Credit: Oxford Instruments NanoAnalysis
Researchers can simply place their sample in the SEM to obtain a quick overview in just five minutes. From there, they can focus on specific areas of interest and proceed accordingly. Another approach is to collect high-resolution data from the entire sample, possibly taking around 30 minutes to an hour. They can then analyze the data offline, reducing the time spent on the SEM.
This technology introduces new working methods and potentially opens doors to new applications.
What specific challenges or limitations did you encounter during the development and implementation of the BEX technology, and how were they addressed?
Developing Unity, the first BEX detector, took us about five years. It involved a large team working on various aspects of the technology, both hardware and software.
Throughout this process, we encountered numerous challenges, including compacting the components typically found in an average EDS detector—collimator, electron trap, window, and sensor—below the polepiece within just a few millimeters.
To achieve this, we had to use different components and integrate two types of sensors, the backscattered electron sensor and the X-Ray sensor, close to each other in a highly compact space. Despite the difficulties, our team successfully overcame this challenge.
Image Credit: Oxford Instruments NanoAnalysis
On the software side, the Unity builds on our previous work in live chemical imaging, which we developed a few years ago. This prior experience served as a solid foundation.
We also had to make extensive software enhancements to accommodate multiple BSE and X-Ray sensors simultaneously. With the high throughput of X-Ray sensors producing numerous counts, we needed to process the incoming data live, detect the elements present on the sample in real time, and display this information to the user. These software improvements required substantial resources and dedicated development efforts.
Overall, our team accomplished an outstanding job in developing Unity, combining the advancements in hardware and software to create a cutting-edge BEX detector, leveraging live chemical imaging as a crucial foundation for the technique's success.
What specific applications or industries will benefit from implementing the BEX technology?
Anyone using SEM will benefit significantly from this advancement. It allows a transition from indicative information about the sample's topography or chemistry to more precise details of its composition, combining all relevant data. Most users stand to gain from this improvement.
Specific customers seeking particular elements or potential contaminants will find it especially advantageous. Quality control, failure analysis labs, and similar applications will find it ideal, as it significantly enhances throughput and reduces time-to-results. This is one of the primary applications.
What potential impacts do you foresee the BEX technology having in the scientific community or relevant industries? How does the BEX technique contribute to advancements in scientific research?
This technique will increase productivity and reliability. For example, during a previous case, a customer assumed they had only one type of contamination visible through a backscattered electron image. However, they were unaware of another contamination type, not visible even in the backscattered electron image, which we were able to detect using Unity.
This technique enhances reliability and expands knowledge in such applications, revealing hidden elements that may go unnoticed in conventional analysis. It also significantly improves the productivity of the SEM itself. Instead of analyzing only three or four samples daily, this technique can potentially analyze ten to 20 samples in the same timeframe.
Do you have any plans to refine or expand the capabilities of the BEX technology?
Unity is just the beginning, as BEX is an innovative technique. Unity serves as the initial detector, but we continuously advance in this field, focusing on software and hardware improvements. We plan to introduce additional Unity detectors with distinct features in the future.
Image Credit: Oxford Instruments NanoAnalysis
About Haithem Mansour
Dr. Haithem Mansour graduated with a PhD in Material Science from the University of Lorraine in France. He joined Oxford Instruments in 2016 and has always worked with a strong focus in electron microscopy and microanalysis. Haithem has focused his research in ECCI, EBSD and EDS, in particular the development and improvement of these analytical techniques. He is currently working as BEX/EDS Product Manager within the Nanoanalysis marketing team, where he helps design, develop and market new analytical systems.
About Oxford Instruments
Oxford Instruments is a leading provider of high-technology products and services to industrial companies and scientific research communities worldwide. Oxford Instruments’ cutting-edge solutions address pressing global challenges, fostering a greener economy, increased connectivity, improved health, and advancements in scientific understanding. With a steadfast commitment to innovation, Oxford Instruments is proud to be recognized as an industry leader, making a significant difference in the world.
This information has been sourced, reviewed and adapted from materials provided by Oxford Instruments Nanoanalysis.
For more information on this source, please visit Oxford Instruments Nanoanalysis.
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