Simulation of charge collection efficiency for EBAPS with uniformly doped substrate

De, 宋德 Song; Feng, 石峰 Shi; Ye, 李野 Li

doi:10.3788/irla201645.0203002

Cited by 4 publications

(3 citation statements)

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“…Specifically, and the resolution of the EBCMOS might As shown in Fig. 4(a), one can find that the RBI decreases with increasing Al2O3 layer thickness, because the RBI for the Si layer is larger than that for Al2O3, and the depths of the incident electrons are concentrated in the surface [10], [22].…”

Section: A the Influence Of Passivation Layer Materials On Backscatte...mentioning

confidence: 98%

Characterising Backscattered Electrons in EBCMOS

Wang

Jiao³

et al. 2022

IEEE Photonics J.

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The characteristics of backscattered electrons near the surface of a back-side bombarded CMOS (BSB-CMOS) within an electron bombarded CMOS (EBCMOS) were studied based on the principle of electron-solid interactions and Monte-Carlo simulation method. We mainly focused on the angular distributions of backscattered electrons, the ratio of backscattered electron number to incident electron number (RBI), and the distribution of the distance between backscattered electrons and incident electrons (DBI). We studied how these characteristics were affected by the BSB-CMOS surface structure and incident electron energy. Firstly, RBI and the mean DBI vary with the incident electron energy, the surface material type, and passivation layer thickness. Meanwhile, a lower RBI may reduce device noise originating from backscattered electrons (NBE) due to the smaller number of backscattered electrons. Besides, the lower mean DBI may enhance the device resolution, because the backscattered electron beam is more concentrated. The distribution of backscattered azimuths (ΦB) and the backscattered angle (θB) follow uniform distribution and cosine angular distribution respectively, which are difficult to change. Finally, devices with the lowest RBI and a low mean value of DBI were achieved when the BSB-CMOS surface was modified with 60 nm Al2O3 and the incident electrons were at 4 keV, which might improve the NBE and resolution of the EBCMOS. This study will provide a theoretical foundation for the fabrication of high-resolution EBCMOS.

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Section: A the Influence Of Passivation Layer Materials On Backscatte...mentioning

confidence: 98%

Characterising Backscattered Electrons in EBCMOS

Wang

Jiao³

et al. 2022

IEEE Photonics J.

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“…Therefore, it helps electron focusing when the electron multiplier layer has high conductivity and are attached close to the anode. But the doping concentration (1 × 10 19 atoms/cm 3 ) is too high to collect multiplier electrons, [22] so we further study the influence of doping concentration on the electrostatic distribution when the surface of the BSB-CMOS is in contact with the anode.…”

Section: A Simulation Of the Electrostatic Distribution When The Higmentioning

confidence: 99%

“…Results reveal no distortion of the equipotential surfaces between the photocathode and anode, indicating that this electrostatic field will have the function of focusing electrons. At the same time, this configuration can effectively prevent most of the multiplier electrons from being recombined because the 30 nm highly-doped layer is much thinner than the incident depth for the high-energy electron [22]. Fig.…”

Section: ) the Influence Of Doping Concentration On The Electrostatimentioning

confidence: 99%

Simulation of the Electrostatic Distribution in the Proximity Focusing Structure of an EBCMOS

Wang

Chen

et al. 2020

IEEE Photonics J.

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The electrostatic distribution of an electron bombarded CMOS (EBCMOS) was simulated by Ansoft Maxwell 3D software. Specifically, we studied how the electrostatic distribution was affected by the structure of a backside bombarded CMOS (BSB-CMOS) and the anode position in electron-bombarded sensors. The simulation results reveal that the electrostatic field may cause a fault in the signal readout of the BSB-CMOS when the anode is positioned under the BSB-CMOS. In contrast, we found that the structure of an EBCMOS will aid electron focusing when the anode is positioned above the BSB-CMOS and the doping concentration of the electron multiplier layer is high. However, the high doping concentration of the electron multiplier layer will reduce the electron collection efficiency due to its rapid electron-hole recombination. We then designed a structure in which the multiplier layer has an overlying ultra-thin highly-doped layer, with an electrostatic distribution that functions to focus electrons. At the same time, this configuration can effectively prevent most of the multiplier electrons from recombining because ultra-thin highly-doped layer is much thinner than incident depth for the high-energy electron. This simulation study will provide a theoretical foundation for the fabrication of high-performance EBCMOS devices. Graphic abstract: a) EBCMOS physical model in Ansoft Maxwell 3D; b) The distribution of electrostatic distribution for BSB-CMOS with an ultra-thin heavily-doped layer. Electrostatic distribution of EBCMOS with different configurations were simulated. The results reveal that the electrostatic field may cause an erroneous readout of the BSB-CMOS if the anode is positioned under the BSB-CMOS. If the high voltage anode is positioned above the CMOS sensor, this is improved, especially when an ultrathin highly-doped multiplier layer is added to improve electron collection efficiency. This study provides a theoretical foundation for the fabrication of high performance EBCMOS devices.

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