Silicon Radiation Sensors With Resistive Strings for Accurate Position Readout

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Solution Overview

Problem

Existing radiation detectors with resistive reading systems suffer from position reconstruction distortions due to non-uniform charge distribution, leading to systematic errors in determining the impact point of ionizing radiation.

Innovation Solution

The introduction of low-resistance strings connecting reading electrodes, with varying electrical resistance along their length, to distribute the generated charge uniformly among electrodes, reducing distortions and enhancing the accuracy of the position reconstruction, the low-resistance strings are designed to distribute the charge uniformly among the electrodes, minimizing reconstruction errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional resistive reading systems are used without low-resistance strings, then the device structure is simpler, but position reconstruction suffers from systematic distortions and inaccuracies

Engineering Contradiction:
Improveposition reconstruction accuracyVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

Low-resistance strings are introduced as intermediary conductive elements connecting the resistive surface to the reading electrodes. These strings act as mediators that redistribute charge between the impact point and electrodes, correcting the non-uniform charge distribution that causes position reconstruction distortions. The strings have resistance values specifically designed to be low compared to the resistive surface, enabling effective charge redistribution without significantly loading the signal.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The resistance values of the connecting paths are modified by introducing low-resistance strings with specific resistance characteristics. The strings have resistance per unit length that varies along their length, with maximum resistance at the midpoint between electrodes and decreasing toward the electrodes. This parameter optimization enables accurate charge distribution for position reconstruction while maintaining structural feasibility.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If low-resistance strings with varying resistance are introduced to correct position distortions, then position reconstruction accuracy improves, but the device structure becomes more complex

Engineering Contradiction:
Improveposition reconstruction accuracyVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The low-resistance strings exhibit non-uniform resistance distribution along their length, with the resistance per unit length varying to achieve optimal charge distribution. The resistance is maximum at the midpoint between electrodes and decreases toward the electrodes, creating local variations in electrical properties that correct position reconstruction distortions in different regions of the detector.

Inventive Principle:
Principle #3Local quality

3Measurement precision

If uniform resistance strings are used to connect reading electrodes, then some charge distribution improvement is achieved, but position reconstruction distortions are not fully eliminated

Engineering Contradiction:
Improveposition reconstruction accuracyVSAvoiddevice structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The resistance per unit length of the low-resistance strings is specifically designed to vary along the length of the string, with maximum resistance at the midpoint between electrodes and decreasing toward the electrodes. This non-uniform resistance parameter optimization enables accurate charge distribution and eliminates position reconstruction distortions that cannot be corrected with uniform resistance strings.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The solution effectively reduces position reconstruction distortions to negligible levels, ensuring accurate determination of the radiation impact point by compensating for non-uniform charge distribution.

Implementation Method 1

the reading electrodes are connected to each other by strings with low electrical resistance. These strings have the purpose of distributing the charge that the electrodes receive following the impact of the radiation on the device

Methodology Applied
Scientific EffectElectrical conduction: Conduction (electrical)

Data Source

PatentEP4479779B1Silicon sensors with resistive reading without image distortion
Publication Date: 2025.12.24 ISTITUTO NAZIONALE DI FISICA NUCLEARE
  • EP4479779B1 patent drawingFigure 1a~1b
  • EP4479779B1 patent drawingFigure 2
  • EP4479779B1 patent drawingFigure 3

AI summary

The invention relates to semiconductor devices for detecting ionizing radiation with a position sensitive resistive reading system, with low resistance connections (strings) between the reading electrodes to limit distortion in determining the impact position of the radiation. The present invention focuses on the optimal characteristics of said strings, varying their doping level and/or their geometric characteristics as a function of their length L, so as to modulate their electrical resistance. In this way it is possible to optimize the precision of the reconstruction of the point of impact of the ionizing radiation, reducing the distortion in the reconstruction of the position of the events up to making it negligible.