Simulation of Guard Ring Type Effects on the Electrical Characteristics of n-on-p Planar Silicon Detectors

Authors M. Mekheldi1, 2 , S. Oussalah2, A. Lounis3, N. Brihi1

1Université Mohammed Seddik Benyahia de Jijel, Ouled Aissa, 18000 Jijel, Algeria

2Centre de Développement des Technologies Avancées, Cité 20 août 1956, Baba Hassen, 16303 Algiers, Algeria

3Laboratoire de l’Accélérateur Linéaire, Université Paris-Sud XI, CNRS/IN2P3, Orsay, France

Issue Volume 11, Year 2019, Number 4
Dates Received 20 December 2018; revised manuscript received 26 June 2019; published online 22 August 2019
Citation M. Mekheldi, S. Oussalah, A. Lounis, N. Brihi, J. Nano- Electron. Phys. 11 No 4, 04008 (2019)
PACS Number(s) 07.05.Tp, 85.30.Mn, 29.40. – n
Keywords Breakdown voltage, Guard rings, Planar silicon detector, Radiation damage, TCAD simulation.

The upgrades of high-energy physics experiments at the Large Hadron Collider (LHC) at CERN will call for new radiation hard technologies to be applied in the next generations of tracking devices that will be required to withstand extremely high radiation doses. N-on-p planar pixel sensors are promising candidates and to be implemented in the future ATLAS pixel detector. In this work, we present a comparative study for two different designs of multi-guard structures, before and after irradiation. Both structures are based on the p-type substrate technology with and without p-stop isolation between implants. Moreover, one structure has p-type guard rings while the other has n-type ones. Various technological parameters are varied like thickness and doping of the silicon substrate, depth and doping of the guard rings, and thickness of the silicon dioxide to study the electrical performances of the structures. The performance of the multi-guard ring structures are evaluated with TCAD simulations up to a radiation fluence of 1 x 1016 neq/cm2 using an existing p-type bulk radiation damage model based on the so called “Perugia three level traps model”, where irradiation generates two acceptor levels, positioned slightly above the mid bandgap, and one donor level, located below the mid bandgap. We have considered an increasing amount of oxide charge with the irradiation dose. For a good quality SiO2 layer, an initial charge density at the interface layer was set to 5 x 1010 cm–2 for a non-irradiated detector, whereas for a heavily irradiated structure the charge density value can reach 1 x 1012 cm–2. They have been simulated on high resistivity silicon wafers using Silvaco Virtual Wafer Fab (VWF) software.

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