OMEGAPIX2: 3D integrated circuit prototype dedicated to the ATLAS pixel detector for the High Luminosity LHC

The OMEGAPIX2 chip embeds a matrix of channels implemented in two vertically integrated (3D) circuits and designed to read out a matrix of 96×24 plannar pixels. The form factor of each pixel is 35×200 μm. The first 3D devices's layer includes the analogue part of the channel processing, it will be bounded to the sensor by connecting the channel inputs and the sensors pixels by the Through Silicon Vias (TSV); the other layer performs the digital memorization of each events and manages the sorting of good events after the Level 1 (L1) trigger acquisition. In this paper, the 3D technology is briefly described, some design considerations are discussed and some typical simulations are shown. The circuit has been submitted in October 2011 and is waited to be received in December 2012.