Superconducting X-ray Detectors Research Articles

Superconducting X-ray Sensors for Tomography of Microelectronics

Abstract The high energy-resolving power of superconducting x-ray detectors reduces unwanted x-ray backgrounds, uses x-ray photons efficiently, and allows for discrimination among multiple chemical elements in a sample. This article discusses the challenges of analyzing the internal structure and composition of integrated circuits, and how 3D imaging can benefit manufacturers and researchers. It covers the development of superconducting x-ray sensors, their advantages over traditional sensors, potential applications, and focus areas for future work to develop this technology.

Stability Evaluation of Superconducting X-ray Detectors for SEM-EDS Analyzer.

Stability Evaluation of Superconducting X-ray Detectors for SEM-EDS Analyzer.

Superconducting X-ray detectors

Owing to their high sensitivity and low noise, superconducting detectors are used for photon detection from microwave to high-energy particles. X-ray detection plays an important role in materials analysis, astronomy, and medical radiography, which require high efficiency as well as high energy resolution. However, traditional semiconducting detectors cannot fulfill these requirements. In this article, we review superconducting quantum detectors for X-ray detection, including transition-edge sensor (TES), superconducting tunneling junctions (STJs), kinetic inductance detectors (KIDs) and superconducting nanowire single-photon detectors (SNSPDs), and introduce the physical structures, working mechanisms, and device behaviors of these detectors. We also review their performances regarding X-ray detection and analyze their respective characteristics. According to recent progress and the requirements of various applications, possible improvement of superconducting detectors for X-rays are discussed.

Development and Application of SEM-EDS Analyzer Utilizing Superconducting X-ray Detector

Development and Application of SEM-EDS Analyzer Utilizing Superconducting X-ray Detector

Cross-sectional TEM study of the microstructure of superconducting X-ray detectors based on thin W–Al layers

The relation between structural and morphological properties and the performance of X-ray detectors have been studied by means of cross-sectional transmission electron microscopy (XTEM) and low temperature electrical measurements. The detectors consist of a strip of an aluminium thin film in contact with superconducting phase transition thermometers based on tungsten films at its both ends. Soft X-ray photons are absorbed in the sapphire substrate underneath the Al film and create high energy phonons. These phonons enter the superconducting film and break up Cooper-pairs into quasiparticles which then diffuse into the W films and create correlated thermal signals in both thermometers. XTEM investigations revealed a polycrystalline structure of the Al films above both the bare sapphire and chemically etched areas of the highly oriented W films, while the Al is single crystalline above the intact W film surface showing an orientational relationship: (2 0 0) Al∥(0 2 0) W∥( 0 1 1 ̄ 2)Al 2O 3 and [0 2 ̄ 2 ] Al∥[2 0 0] W∥[ 1 0 1 ̄ 2 ̄ ] Al 2 O 3 . No remarkable difference in morphology and structure of the layers of the two detector sides was observed. On the other hand, irregular saw-tooth-like interfaces of different profiles of low slope were found between the chemically etched regions of the W sensor films and the overlapping Al diffusion film. The observed strong asymmetry of the correlated signals is attributed to the disturbed quasiparticle propagation through the observed different interface structures of the two detector sides.

Superconducting NbTaAlAlOxAl X-ray detectors with spatial resolution

Abstract Superconducting X-ray detectors based on SIS tunnel junctions offer potential for high spectral resolution and single photon efficiency. When used in a double junction geometry, they also offer spatial resolution needed for focal plane imaging. We are developing NbTaAlAlOxAl detectors for space-based X-ray astronomy applications. The design employs superconductor bandgap engineering for improved charge collection and adaptability for double junction geometries. For irradiation of a single junction device with 6 keV X-rays at a single location, the detectors have an energy resolution of 87 eV at 0.27 K. Initial studies of double junction detectors show a spectral resolution of 178 eV and an inferred spatial resolution of 4 μm over an effective length of 60 μm.

High-resolution superconducting x-ray detectors with two aluminum trapping layers

Superconducting tunnel junctions coupled to superconducting absorbers may be used as high-resolution, high-efficiency x-ray spectrometers. We have tested three detectors with niobium x-ray absorbing layers coupled to aluminum layers that serve as quasiparticle traps. Two detectors differed only in barrier thickness. A third detector includes an extra absorbing layer. Here we present a comparison of detector performance. The best energy resolution measured was 36 eV full width at half maximum at 6 keV.

On the feasibility of high spatial resolution superconducting X-ray detectors

We discuss a class of superconducting particle/radiation detectors in which the readout is by magnetic means. Even a small energy deposition can change the state of a superconductor, leading to a drastic change of its electromagnetic properties. To increase the detector sensitivity, a highly granulated superconducting medium is used. Millions of physically separated sensors are read out in parallel by only a few channels of very sensitive D.C.-SQUID based electronics. We present the mathematical formulation of the problem and discuss how the excellent signal-to-noise ratio obtained using SQUIDs permits us to determine particle/photon localization.