Development of monolithic sensors for high energy physics in commercial CMOS technologies

Hybrid pixel detectors with readout and sensor in different silicon chips are in overwhelming majority in today’s high energy physics experiments, but monolithic active pixel sensors (MAPS) have received significant attention because they offer easier detector assembly, lower cost, and other advantages like lower material and higher granularity. MAPS now move towards commercial CMOS technologies, which offer significant radiation tolerance and substrates compatible with particle detection and combine circuit performance and density with volume production capability at reasonable cost. MAPS in commercial CMOS technologies were used for the first time in the STAR experiment, adopted for the ALICE experiment, and are being considered for the most aggressive applications, like the ATLAS HL-LHC upgrade and future colliders like the FCC and CLIC. Significant improvements are made in every iteration with challenges in sensor and frontend design, architecture, speed, timing, radiation tolerance and system issues. This paper tries to give an overview. Some considerations on digital power consumption versus hit rate and clock distribution over the pixel matrix are added as well.