Analogue test structures were fabricated using the Tower Partners
Semiconductor Co. CMOS 65 nm ISC process. The purpose was to characterise and
qualify this process and to optimise the sensor for the next generation of
Monolithic Active Pixels Sensors for high-energy physics. The technology was
explored in several variants which differed by: doping levels, pixel geometries
and pixel pitches (10-25 μm). These variants have been tested following
exposure to varying levels of irradiation up to 3 MGy and 10^16 1 MeV
n_eq cm^-2. Here the results from prototypes that feature direct
analogue output of a 4×4 pixel matrix are reported, allowing the
systematic and detailed study of charge collection properties. Measurements
were taken both using ^55Fe X-ray sources and in beam tests using minimum
ionizing particles. The results not only demonstrate the feasibility of using
this technology for particle detection but also serve as a reference for future
applications and optimisations.
