Conceptual design of 3D integrated pixel sensors for the innermost layer of the ILC vertex detector

The paper presents a design of CMOS Pixel Sensor (CPS) using the vertical integra- tion technology (3DIT), expected to alleviate the most essential limitations of 2D-CPS. Our ob- jective is to develop an intelligent architecture in order t o meet the requirements of the innermost layer of the International Linear Collider (ILC) vertex det ectors, which are particularly demanding in spatial resolution of less than 3 μm and associated frame readout time of 10 μs. The sensor, with a pixel pitch of 23 μm, will be composed of 3-tiers Integrated Circuits (IC) with different functionalities: detection with in pixel analogue process ing, pixel-level 3-bit Analogue to Digital Conversion (ADC) and fast parallel sparse readout.