A Monolithic Picosecond Avalanche Detector


The enormous potential of silicon sensors in precise time measurement of ionizing particles is far from being exploited. At present, the best time resolutions in pixelated silicon is obtained by the project consortium that has measured 50 ps with low-noise ultra-fast SiGe HBT electronics. This project introduces a novel silicon sensor with a gain layer that uses a fully depleted multi-junction structure. Full simulations of the sensor predicted excellent results: pixels of 50 x 50 μm2 can be achieved with few μm inter-pixel spacing together with picosecond-level time resolution in a monolithic sensor of thickness down to 25 μm. These results will be combined with a monolithic implementation and a simplified assembly process.

IHP's Contribution

The monolithically integrated sensor designed by project partners University of Geneva and EPFL is fabricated at IHP in a multi-project-wafer fabrication of the high-performance SiGe BiCMOS technology SG13G2. In addition, IHP develops a fabrication process for the integration of a gain layer in the Si substrate. In a second fabrication run, the integrated sensor chips are processed in SG13G2 technology on pre-processed wafers with integrated gain layers.


This project has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 777222 (ATTRACT).

Project Partners

  • University Geneva
  • INFN Tor Vergata
  • EPFL Lausanne

Selected Publications

  • G. Iacobucci et al., “A 50 ps resolution monolithic active pixel sensor without internal gain in SiGe BiCMOS technology”, Journal of Instrumentation”, vol. 14, p. 11008 (2019)

External Links

The website is designed for modern browsers. Please use a current browser.