Design and optimization of a novel 3D detector: The 3D-open-shell-electrode detector

Manwen Liu,Jian Tan,Zheng Li

doi:10.1063/1.5023188

Abstract

A new type of three-dimensional (3D) detector, namely 3D-Open-Shell-Electrode Detector (3DOSED), is proposed in this study. In a 3DOSED, the trench electrode can be etched all the way through the detector thickness, totally eliminating the low electric field region existed in the conventional 3D-Trench-Electrode detector. Full 3D technology computer-aided design (TCAD) simulations have been done on this novel silicon detector structure. Through comparing of the simulation results of the detector, we can obtain the best design of the 3SOSED. In addition, simulation results show that, as compared to the conventional 3D detector, the proposed 3DOSED can improve not only detector charge collection efficiency but also its radiation hardness with regard to solving the trapping problem in the detector bulk. What is more, it has been shown that detector full depletion voltage is also slightly reduced, which can improve the utility aspects of the detector. When compared to the conventional 3D detector, we find that the proposed novel 3DOSED structure has better electric potential and electric field distributions, and better electrical properties such as detector full depletion voltage. In 3DOSED array, each pixel cell is isolated from each other by highly doped trenches, but also electrically and physically connected with each other through the remaining silicon bulk between broken electrodes.

Highlights

With the development of semiconductor industry, advanced processing technologies have been applied to the fabrication of novel semiconductor detectors in recent years
We will propose a new type of 3D detector, namely the 3D-Open-Shell-Electrode Detector (3DOSED) to eliminate this virtual dead space, while still keep the easy one-sided detector processing and good advantages of the conventional 3D-Trench-Electrode detector
Focus on improving the detection efficiency and radiation hard, we propose a novel 3D-Open-Shell-Electrode Detector (3DOSED) with p-type bulk silicon or n-type bulk silicon

Summary

INTRODUCTION

With the development of semiconductor industry, advanced processing technologies have been applied to the fabrication of novel semiconductor detectors in recent years. Two major electrical effects are observed because of the build-up of radiation induced defect levels in the detector: a linear increase of the leakage current and an increase of the full depletion voltage as a function of radiation fluence.[11] In addition to the problem of full depletion, the issue of trapping will be the main limiting factor to the detector Charge Collection Efficiency (CCE).[12]. Both 3D-Trench-Electrode detector and 3D column electrode detector require the processing of deep Si etching. This may result in a virtual dead space, namely low electric field area, as much as 10% in volume, in the detector.[13,14] In this article, we will propose a new type of 3D detector, namely the 3D-Open-Shell-Electrode Detector (3DOSED) to eliminate this virtual dead space, while still keep the easy one-sided detector processing and good advantages of the conventional 3D-Trench-Electrode detector

DESIGN AND DEVICE DESCRIPTION

ANALYSIS OF 3D SIMULATIONS

Findings

CONCLUSIONS