Monolithic CMOS pixel detectors have emerged as competitive contenders in the field of high-energy particle physics detectors. The use of commercial processes offers high-volume production of such detectors.
A series of prototypes has been designed in a 180$\,$nm Tower CMOS process with depletion of the sensor material and a column-drain readout architecture.
The latest iteration, TJ-Monopix2, features a large 2 x 2$\,$cm$^\text{2}$ matrix consisting of 512 x 512 pixels with 33.04$\,$um pitch.
A small collection electrode design aims at low power consumption and low noise while the radiation tolerance for high-energy particle detector applications needs extra attention.
With a goal to reach radiation tolerance to levels of NIEL damage of 10$^\text{15}\,$1$\,$MeV$\,$n$_\text{eq} / $cm$^\text{-2}$, a modification of the standard process has been implemented by adding a low-dosed n-type silicon implant across the pixel in order to allow for homogeneous depletion of the sensor volume.
Recent lab measurements and beam tests were conducted for unirradiated modules to study electrical characteristics and hit detection efficiency.