HVCMOS pixel detectors — methods for enhancement of time resolution

Abstract

High-Voltage CMOS (HVCMOS) pixel sensors are depleted active pixel sensors implemented in standard commercial CMOS processes. HVCMOS pixel sensors will be used, or are proposed, for several experiments: Mu3e, ATLAS, CLIC. Thanks to charge collection with a high electric field, HVCMOS sensors have potentially a very high time resolution. The time resolution is limited by the rise time of the amplifier. In this article, means for enhancement of time resolution are described: A compensation method shifting the detection time depending on the signal height, an enhanced comparator — the time walk compensating comparator — and the sampling of the signal.