Workshop on the Future of Silicon Detector Technologies - FuTuRe III


About this workshop

While the technical progress in science, industry and everyday life is speeding up, there is a constant need in improving sensors in terms of higher sensitivity, higher reliability and better dynamics.
One type of sensor which could keep pace with the requirements of innovation for the last decades is the silicon based sensor. The silicon diode has established itself in many fields of applications (s. below). We will discuss open questions, such as reliability in terms of radiation hardness. Another topic of our workshop is high-speed and low-power signal processing, which is important for passing all the data from sensors to electronics.

Dosimetry in radiation therapy
In the last two decades, the radiotherapy in its traditional form with photons and electrons saw an introduction of new treatment methods which aimed at concentrating the radiation to the cancerous regions and saving the surrounding healthy region. Nevertheless there is still the need to reduce the uncertainty in predicting dose and position of the actually applied radiation absorbed in the human tissue. In more advanced hadron radiation therapies, there is even a stronger need to concentrate the radiation exactly at the position of the cancer. Therefore new kinds of detectors have to be developed to solve these problems.

Readout electronics
Sensors have to transfer signals to electronics. One trend in electronics is high-speed and low-power signal processing. This can be done with adiabatic quantum-flux-parametron (QFP) logic digital circuit designs, which are based on QFP gates and which require low temperatures. Another highlight of modern sensor technology, which also employs low temperatures, is the superconducting nanowire single-photon detector (SNSPD) technology.
Another topic is the electronics that is specially designed for detecting ionising radioation with high dynamics.

Sensor development for x-rays
A technology, which is gaining momentum very fast, is the creation of coherent, brilliant x-ray radiation. The Swiss Light Source (at the Paul Scherrer Institut, Switzerland) and the European XFEL (near Hamburg) are examples for novel machines where new insights into health, materials, environmental and other sciences are obtained. But this can only be done when sensors and detectors are produced and optimised in respect of lateral, time and energy resolution and high dynamics. It has to be discussed how this can be achieved on wafer, assembly and electronics level.

Defect engineering
Defect engineering is required where sensors and detectors are exposed to intense high energy radiation (in high energy physics, heavy ion research, but also in medical dosimeters). This radiation induces defects in the sensor’s active region leading to a reduction in its sensitivity. A new type of semiconductor sensor for the same applications is the low gain avalanche detector (LGAD), which features a deeply doped boron gain layer where carriers are accelerated and thus pass the layer very quickly, enabling a high temporal resolution and making them prone to radiation damage. Radiation hardness can be improved by a proper defect engineering.