Speaker
Description
The Silicon Electron Multiplier (SiEM) is a novel sensor concept for minimum ionizing particle detection, expected to provide excellent timing and spatial resolution through a sub-$10\,\mu m$ pixel pitch and internal gain designed to be radiation-hard. Unlike conventional devices, where the gain layer is formed by ion implantation and tends to degrade under radiation due to acceptor removal, the SiEM employs metal electrodes embedded in the silicon substrate using MEMS technology, and should thus be able to withstand high fluences. The electrostatic potential applied to the embedded electrodes generates a high-field region in which drifting charges multiply. TCAD simulations confirm the promising potential of this technology for future collider experiments in extreme radiation environments, with predicted gain values above 10 and timing precision on the order of 40 ps.
In this contribution, we report on the status of the various fabrication methods and present the first experimental results obtained with pixelated sensors produced by Hamamatsu. These demonstrators were manufactured in several variants, with pixel pitches down to $5\,\mu m$.
IV and CV characteristics of the demonstrators have been measured, providing insight into the sensor behaviour. The current increase observed when varying the voltage of the amplification electrode gives a first estimation of the gain. These studies were further complemented by test-beam campaigns at CERN SPS, where the gain as a function of the amplification bias was measured based on the amplitude of the response to minimum ionizing particles. This confirmed the current measurements and represents the first experimental validation of the gain mechanism underlying the SiEM concept. The results demonstrate the feasibility and potential of SiEM technology for the development of next-generation radiation-hard tracking detectors.
| Position | Doctoral Student |
|---|---|
| Affiliation | CERN |
| Country | Switzerland |