As semiconductor technology pushes into nanometre and sub-nanometre territory, the SEM (scanning electron microscope) instruments used to inspect these chips must operate with exceptional precision.
In this blog, we put high voltage power supplies under the microscope to examine why they are essential to a SEM’s performance and how their design directly impacts imaging accuracy, measurement repeatability, and overall inspection reliability.
Overview
How SEM performance is closely tied to high voltage power supply quality
Critical technical requirements for achieving stability, low noise, and precision in power delivery in SEMs
How XP Power’s HRF15 series meets the most demanding application needs
Expanding applications beyond SEMs, including medical imaging and analytical instrumentation
Analytical instruments such as SEMs are fundamental in verifying dimensions, detecting defects, and ensuring the structural integrity of micro- and nano-scale features on wafers.
Behind the scenes, a high voltage power supply is a silent enabler of this precision. It generates the stable, exact voltages that control the SEM’s electron beam. If the power supply is unstable or noisy, the results can be skewed: images may blur, measurements may falter, and misinterpretations may lead to costly manufacturing errors.
Taming ripple and noise for image precision and clarity
Modern SEMs used in semiconductor fabrication must deliver consistently sharp, reliable imagery. Achieving this clarity requires a high voltage power supply with extremely tight performance characteristics. One of the most critical aspects is minimizing ripple and noise, since any unwanted fluctuations can distort the electron beam, degrading image resolution and clarity.
Equally important is stability over time as voltage drift across hours can directly impact repeatability. A power supply with poor long-term stability may either mask true defects or falsely flag non-existent issues.
Protecting performance through thermal stability
Your power supply's thermal stability plays a significant role in SEM performance as variations in ambient temperature can cause voltage fluctuations unless the system maintains a low temperature coefficient.
Load and line regulation is yet another factor to consider. The output voltage must remain consistent despite variations in input power or load changes. Together, these features help maintain reliable and stable operation under varying conditions.
Reducing noise for maximum image quality and yield
Finally, low partial discharge is essential, as these micro-discharges introduce noise that compromises both image quality and system reliability. At the nanometre scale, even the smallest deviations matter. In sub-5nm processes, such errors can result in incorrect yield predictions, wasted wafers, or undetected flaws.
Rising to the challenge with XP Power’s HRF series
To support these high precision applications, we’ve developed the HRF15 series of high voltage DC-DC converters, engineered specifically for applications such as SEMs where stability, noise suppression, and compactness are essential.
Its capabilities allow the HRF15 to support complex, multi-beam systems with high uptime demands. Key product features include:
Ultra-low ripple and noise
Ripple levels as low as 0.001% ensure the HRF15 maintains electron beam integrity and prevents image distortion.
Exceptional long-term stability
A rating of 10 ppm/hour and 25 ppm over 8 hours after warm-up ensures that beam energy and inspection results remain consistent throughout entire production shifts.
Superior thermal performance
A temperature coefficient of 25 ppm/°C means the voltage remains stable even with changing environmental conditions.
Precise load and line regulation
With a variation of just 0.001%, the HRF15 ensures unwavering voltage delivery despite input or load variations.
Compact design
Measuring only 162.6 x 72.4 x 33 mm, the HRF15 delivers high performance in less than half the volume of many alternatives and gives the flexibility to be closer to the point of load.
Programmability and integration
Provides 0–100% output voltage and current programming via an analog input and built-in voltage and current monitoring to deliver the flexibility that modern SEMs require.
The HRF15 delivers ultra-stable, low-noise high voltage to ensure SEM precision at the nanometre scale
Applications beyond SEMs
While SEMs are the primary focus, the HRF15 is equally suited for a variety of high performance applications where voltage stability and low noise are mission critical. These include mass spectrometry, e-beam and ion beam instruments, capillary electrophoresis, high voltage biasing circuits, and medical and analytical detectors, among other applications. Use cases such as these share similar demands for drift-free, low ripple voltage output.
Building a foundation for reliability and accuracy
The performance of an SEM and the accuracy of semiconductor process control rely heavily on the quality of its high voltage power supply. XP Power’s HRF15 series addresses this need with a combination of low noise, ultra-high stability, and compact form factor, setting a high bar for what precision power delivery should look like in analytical instrumentation.
Summary
In SEM applications where every nanometre counts, the HRF15 ensures the stable, noise-free power delivery essential for accurate imaging and consistent measurements.
As demands for inspection precision continue to grow, the series provides the precise and accurate high voltage power needed to support the next generation of semiconductor innovation.
Explore our high voltage products for SEM, including top-beam systems with precision output voltages ranging from 30kV to 100kV.
Hafiz Khalid
Hafiz is XP Power’s Director of Product Marketing. He has worked in design, application, solution engineering, and product management roles for various products for the past 18 years. Previously, he was Senior Product Manager at XP Power and High Voltage designer with EMCO High Voltage which was acquired by XP Power in 2015.
