Dec 2 – 4, 2015
CERN
Europe/Zurich timezone

Effect of Al2O3 passivation layer in irradiated n-on-p strip sensors [Thursday]

Dec 3, 2015, 5:40 PM
20m
6/2-024 - BE Auditorium Meyrin (CERN)

6/2-024 - BE Auditorium Meyrin

CERN

6-2-024
114
Show room on map
Standard (20 min including discussion) Simulations

Speaker

Timo Hannu Tapani Peltola (Helsinki Institute of Physics (FI))

Description

The significant advantages of detectors manufactured on p-type silicon material over n-type detectors in the HEP particle tracking applications have been well documented in the R&D community. In AC-coupled p-type position-sensitive strip detectors, however, the fixed oxide charge in the silicon dioxide is positive and, thus, causes electron accumulation at the Si/SiO2 interface. Thus, the n-type strips become short-circuited without additional isolation implantations. The higher processing complexity resulting from this requirement can be avoided by the use of aluminum oxide (Al2O3, alumina) thin-film insulator, grown by Atomic Layer Deposition (ALD) method. The negative oxide charge in ALD-oxide provides strip isolation without any additional isolation structures. Measurement and TCAD simulation study of a MOS test structure with alumina layer show a considerable accumulation of negative oxide charge in ALD-oxide after Co-60 gamma-ray irradiations. Also a comparative study of the simulated surface properties between alumina, p-stop and p-spray sensors will be presented. Furthermore, measurements of 2e15 neq/cm2 proton irradiated p-type MCz-Si strip sensors with alumina thin-film insulator are compared to the simulations of corresponding sensor design as well as with conventional isolation structures.

Summary

The effect of Al2O3 passivation layer in n-on-p strip detectors irradiated by protons up to 2e15 neq/cm2 was studied both by measurements
and TCAD simulations. The accumulation of negative oxide charge in ALD-oxide was verified by Co-60 gamma-ray irradiations.

Authors

Jasu Haerkoenen (Helsinki Institute of Physics (FI)) Timo Hannu Tapani Peltola (Helsinki Institute of Physics (FI))

Presentation materials