Abstract
Abstract
Samples of the monolithic silicon pixel ASIC prototype
produced in 2022 within the framework of the Horizon 2020 MONOLITH
ERC Advanced project were irradiated with 70 MeV protons up to a
fluence of
1 ×
1016 neq/cm2, and then tested using a beam of
120 GeV/c pions. The ASIC contains a matrix of 100 μm pitch
hexagonal pixels, read out by low noise and very fast frontend
electronics produced in a 130 nm SiGe BiCMOS technology process.
The dependence on the proton fluence of the efficiency and the time
resolution of this prototype was measured with the frontend
electronics operated at a power density between 0.13 and
0.9 W/cm2. The testbeam data show that the detection efficiency
of 99.96% measured at sensor bias voltage of 200 V before
irradiation becomes 96.2% after a fluence of
1 ×
1016 neq/cm2. An increase of the sensor bias
voltage to 300 V provides an efficiency to 99.7% at that proton
fluence. The timing resolution of 20 ps measured before
irradiation rises for a proton fluence of
1 ×
1016 neq/cm2 to 53 and 45 ps at HV = 200
and 300 V, respectively.