Nuclear Instruments and Methods in Physics Research A 579 (2007) 604–607 Characterisation of p-type detectors for the future Super-LHC C. Lacasta a,Ã , F. Campabadal b , C. Fleta b , C. Garcı´a a , M. Lozano b , S. Martı´ a , M. Min˜ano a , G. Pellegrini b , J.M. Rafı´ b , M. Ulla´n b a Instituto de Fı´sica Corpuscular, IFIC (CSIC-UVEG), P.O. Box 22085, E-46071 Valencia, Spain b Instituto de Microelectro´nica de Barcelona, CNM-IMB (CSIC), 08193 Bellaterra, Barcelona, Spain Available online 24 May 2007 Abstract A technology for the fabrication of p-type microstrip silicon radiation detectors using p-spray implant insulation has been developed at CNM-IMB within the RD50 collaboration framework. The p-spray insulation has been designed to withstand the ionising irradiation dose expected in the middle region of the ATLAS tracking system for the future Super-LHC. Detectors have been fabricated with Float Zone and Magnetic Czochralski p-type high resistivity silicon substrates in the Clean Room facility of CNM-IMB, irradiated with neutrons up to a fluence of 10 15 neutrons cm 2 and characterised at IFIC-Valencia. The results show a charge collection efficiency below 40% at 1000 V bias voltage. r 2007 Elsevier B.V. All rights reserved. PACS: 29.40.Gx; 29.40.Wk Keywords: Silicon; p-type; Microstrip; SLHC 1. Introduction The luminosity of the LHC will increase over the first several years of operation reaching 10 34 cm 2 s 1 and, very likely, requiring detector upgrades in critical areas. Over the last years an upgrade of the LHC, the SuperLHC (SLHC) [1], towards higher luminosities ð10 35 cm 2 s 1 Þ has been discussed as an extension of the LHC physics program. Such an upgrade will extend the LHC mass reach and require challenging improvements in the detectors. The SLHC will require the development of a tracking system capable of dealing with an instantaneous luminosity of 10 35 cm 2 s 1 and between 5 and 10 years of further operation, having to withstand fluences of up to 10 16 1 MeV neutrons cm 2 in order to guarantee the opera- tion. In the case of ATLAS, an all-silicon tracker would need to be implemented that would require completely new designs for the factor 10 higher radiation fluences and would have much greater granularity to cope with the much higher occupancies that would rise from the 20 events per crossing at LHC becoming 200 at the SLHC. Three regions can be defined, in the new ATLAS tracking system, according to the radiation level [2]. Pixel sensors will be placed at radii below 20 cm, short strip silicon sensors at intermediate radii and long strip sensors at the outer layers of the inner detector as shown in Fig. 1. Current technologies could well serve for the latter, while the pixels and the short strip sensors will certainly require new concepts. In preparation for this the RD50 [3] collaboration is providing guidelines to the detector technologies which may be employed at the anticipated high radiation levels. The work in this paper has been made in the framework of this collaboration. 2. Short strip silicon sensors The factor 10 increase of luminosity translates into an increase of particle fluences that will further augment the challenges on the detector performance and design. In particular, in order to maintain the same occupancy and track separation capabilities, the area of the sensing elements—pixels and strips—might need to be reduced by ARTICLE IN PRESS www.elsevier.com/locate/nima 0168-9002/$ - see front matter r 2007 Elsevier B.V. All rights reserved. doi:10.1016/j.nima.2007.05.254 Ã Corresponding author. Tel.: +34 96 398 3490; fax: +34 96 398 3488. E-mail address: Carlos.Lacasta@ific.uv.es (C. Lacasta).