Performance of new radiation tolerant thin n-in-p Silicon pixel sensors for the CMS experiment at High Luminosity LHC

The High Luminosity upgrade of the CERN-LHC (HL-LHC) demands for a new high-radiation tolerant solid- state pixel sensor capable of surviving fluencies up to a few 10
¹⁶
particles cm
²
at ∼3 cm from the interaction point. To this extent the INFN ATLAS-CMS joint research activity, in collaboration with Fondazione Bruno Kessler, is aiming at the development of thin n-in-p type pixel sensors for the HL-LHC. The R & D covers both planar and single-sided 3D columnar pixel devices made with the Si-Si Direct Wafer Bonding technique, which allows for the production of sensors with 100µm and 130µm active thickness for planar sensors, and 130µm for 3D sensors, the thinnest ones ever produced so far. First prototypes of hybrid modules bump-bonded to the present CMS readout chips have been tested in beam tests. Preliminary results on their performance before and after irradiation are presented.