TEM-EDS with Breakthroughs in 3D Wiring and High-Speed Processing

Abstract

We have been improving our TEM-EDS for elemental microanalysis after a successful achievement of a high energy resolution (7.8 eV at 1.7 keV) using a TES microcalorimeter. The improvements fall into a 3D superconductive wiring and a high-speed processing (∼3,000 cps). We are implementing a 10-ch TES array for higher count rate and a broader dynamic range. The shape of a probe needs to be a small polygonal rod with an approximate size of 1 cm×1 cm×10 cm, and hence the placing and wiring of the TES array and read-out circuits at the cryogenic stage were very demanding. We overcame those difficulties by 3D photolithography and electrodeposition. With these new technologies, we developed the OFC probe with solder-plated 3D wiring, and successfully observed a superconductivity at the temperature of liquid helium. As a required count rate per channel is ∼300 cps, the overall system count rate is ∼3,000 cps, which is incomparably higher than before. In the last model, we used an embedded system to process waveforms from a 4-ch 14-bit 1 MS/s ADC due to a small signal bandwidth, but this time we parallelized three identical ADCs and transfer raw waveforms by Ethernet lines to a host to achieve the required system count rate.