Buried Layer Low Gain Avalanche Diodes

We report on the design, simulation and test of Low Gain Avalanche Diodes (LGADs) which utilize a buried gain layer. The layer is formed by patterned implantation 50-micron thick float zone substrate wafer-bonded to low resistivity carrier. This then followed epitaxial deposition ≈ 3 micron-thick high amplification region. topside processed with junction edge termination guard ring structures incorporates an AC-coupled cathode implant. design allows for independent adjustment depth density, increasing flexibility. A higher dopant density can also be achieved controlling process thermal budget, improving radiation hardness. first set demonstration devices has been fabricated, including variety structures. TCAD simulation, fabrication flow, preliminary measurements prototype devices.