Recently developed precision timing detector technology based on silicon Low Gain Avalanche Diode (LGAD) although exhibits excellent timing performance, cannot attain 10 µm position resolution needed for advanced 4D detectors. New small pitch detector solutions are being developed which necessitates development of complimentary Application Specific Integrated Circuits (ASICs) and reliable, high-density, low capacitance, readily manufacturable integration technologies to interconnect silicon pixel detectors with high density CMOS front-end integrated circuits. Finalize design for a new custom multi-tier with emphasis on front-end ASIC while concurrently developing a versatile, high-density, high-yield, low-capacitance vertical integration approach based on modified direct bond interconnect technology integration approach to demonstrate vertically integrated detector and ASIC assembly. The Phase I effort is aimed at devising overall architecture of small pixel three-tier ASIC with finalizing front-end consisting of preamplifier, discriminator and charge injector. Overall performance of the analog front-end will be provided by circuit SPICE simulation post-layout. The high-density, low-capacitance integration will be demonstrated on current generation of ASIC and detectors by implementation of low-k dielectric direct bond technology complimented by a detector-scale thermo-mechanical model of the integrated detector-readout assembly and related charge injection, laser irradiation tests to validate the functionality at Fermilab. Novel small pixel, multi-tier ASIC integrated with high-density, low capacitance modified Direct Bond Interconnect technology will find immediate application in detector chips to be used in newly conceived advanced Electron-Ion Collider (EIC) for precision timing and position application. Longer term applications include full vertically integrated highly segmented, high density detectors for nuclear particle detectors, advanced infrared detector for defense and security application for active imaging systems, such as LAser Detection And Ranging (LADAR) and a wide variety of medical imaging applications such as Clinical dosimetry, Positron Emission Tomography (PET) to name a few.
