Full 3D Simulation of the New Closed Shell-Electrode Detector

Mingfu Feng,Zheng Li,Lipeng Tang,Manwen Liu

doi:10.1051/matecconf/201710809003

Abstract

A new structure of 3D detectors has been proposed. In order to separate it from the non-etch-through 3D-Trench electrode detectors, we call it as the Closed Shell-Electrode Detector (CSED, Chinese Patent #ZL201620361767.1). The detector concept of the CSED will be described in detail here. Full 3D simulations of the performance behavior of the CSED will be carried out and presented. These simulations include detector potential, electric field, and electron (or hole) concentration profiles, as well as detector leakage current, capacitance, and charge collection properties. Comprehensive comparisons between the CSED and the non-etch-through 3D-Trench electrode detectors will be made. The novel CSED has much better electric field profiles near the backside and are much better isolated from neighboring cells than that in non-etch-through 3D-Trench electrode detectors.

Highlights

Detectors based on semiconductor materials have been used in various fields such as deep space imaging, medical imaging, tracking in high-energy physics, radiation-trace detection for the purpose of national security, etc
If the column spacing is made much smaller than the detector thickness, they can be fully depleted at much lower bias voltages and exhibit higher radiation tolerance, as compared to planar detectors
In order to overcome this deficiency in the non-etch-through 3D-Trench Electrode detector, a novel structure has been proposed in Xiangtan University (XTU) in 2016

Summary

Introduction

Detectors based on semiconductor materials have been used in various fields such as deep space imaging, medical imaging (e.g., positron emission tomography), tracking in high-energy physics, radiation-trace detection for the purpose of national security, etc. In the LHC (Large Hadron Collider) and HL-LHC (High Luminosity-LHC) at CERN, for example, the total radiation fluence can reach up to 1x1016neq/cm2[1] In such high radiation environment, high radiation will cause displacement damage in Si, which in turn will increase the defect concentration in the detector. The 3D-Trench Electrode detector can be radiation tolerant, and it has more uniform electric field distribution as compared to the 3D column electrode detector This 3D-Trench Electrode structure has a deficiency: the trench electrode can not be fully etched through (or else the detector cell enclosed by the trench electrode will fall off the wafer). In order to overcome this deficiency in the non-etch-through 3D-Trench Electrode detector, a novel structure has been proposed in Xiangtan University (XTU) in 2016. CSED structure concept and 3D performance simulations, including 3D distributions of electric potential, field and hole (electron) concentration; detector electrical properties such as detector leakage current (I) and capacitance (C) as a function of bias voltages (V) (IV, CV); and detector full depletion voltage

Device description and simulation

Full depletion voltage

Conclusion

Findings

Capacitance- Voltage Characteristics