A study of monolithic CMOS pixel sensors back-thinning and their application for a pixel beam telescope

This paper reports results of a detailed study of charge collection and signal-to-noise performance of CMOS monolithic pixel sensors before and after back-thinning to 50 and 40 μ m . This study shows that neither their noise nor their response to ionising particles has been degraded by the thinning process. The thinned chips have been used to build a pixel beam telescope for the ALS 1.5 GeV e - beam test facility. After alignment, an extrapolation resolution better than 9 μ m has been measured for a configuration of four equally spaced pixel detector planes.