Impact of low-dose electron irradiation on n+p silicon strip sensors
W. Adam
,
G. Baulieu
(1)
,
G. Boudoul
(1)
,
C. Combaret
(1)
,
D. Contardo
(1)
,
G. Gallbit
(1)
,
N. Lumb
(1)
,
H. Mathez
(1)
,
L. Mirabito
(1)
,
S. Perries
(1)
,
D. Sabes
(1)
,
M. Vander Donckt
(1)
,
P. Verdier
(1)
,
S. Viret
(1)
,
Y. Zoccarato
(1)
,
J.-L. Agram
(2)
,
E. Conte
(2)
,
J.-Ch. Fontaine
,
J. Andrea
(2)
,
D. Bloch
(2)
,
C. Bonnin
(2)
,
J.-M. Brom
(2)
,
E. Chabert
(2)
,
L. Charles
(2)
,
Ch. Goetzmann
(2)
,
L. Gross
(2)
,
J. Hosselet
(2)
,
C. Mathieu
(2)
,
M. Richer
(2)
,
K. Skovpen
(2)
W. Adam
- Fonction : Auteur
P. Verdier
- Fonction : Auteur
- PersonId : 184664
- IdHAL : patrice-verdier
- ORCID : 0000-0003-3090-2948
- IdRef : 098525859
S. Viret
- Fonction : Auteur
- PersonId : 1093632
- IdHAL : seb-viret
- ORCID : 0000-0002-1935-623X
J.-L. Agram
- Fonction : Auteur
- PersonId : 1147753
- IdHAL : j-l-agram
- ORCID : 0000-0001-7476-0158
- IdRef : 090333748
E. Conte
- Fonction : Auteur
- PersonId : 755000
- IdHAL : eric-conte
- ORCID : 0000-0003-3154-3123
- IdRef : 122530209
J.-Ch. Fontaine
- Fonction : Auteur
- PersonId : 1150261
- IdHAL : jean-charlesfontaine
- ORCID : 0000-0003-4036-5242
- IdRef : 232452342
Résumé
The response of n+p silicon strip sensors to electrons from a Sr-90 source was measured using a multi-channel read-out system with 25 ns sampling time. The measurements were performed over a period of several weeks, during which the operating conditions were varied. The sensors were fabricated by Hamamatsu Photonics K.K. on 200 micrometer thick float-zone and magnetic-Czochralski silicon. Their pitch was 80 micrometer, and both p-stop and p-spray isolation of the n+ strips were studied. The electrons from the Sr-90 source were collimated to a spot with a full-width-at-half-maximum of 2 mm at the sensor surface, and the dose rate in the SiO2 at the maximum was about 50 Gy/d. After only a few hours of making measurements, significant changes in charge collection and charge sharing were observed. Annealing studies, with temperatures up to 80{\deg}C and annealing times of 18 hours, showed that the changes can only be partially annealed. The observations can be qualitatively explained by the increase of the positive oxide-charge density due to the ionization of the SiO2 by the radiation from the {\ss} source. TCAD simulations of the electric field in the sensor for different oxide-charge densities and different boundary conditions at the sensor surface support this explanation. The relevance of the measurements for the design of p+n strip sensors is discussed.