New Radiation Tolerant LGAD for High Energy Physics

Abstract

Low Gain Avalanche Detectors (LGADs) have recently been studied for applications in high energy physics. They provide the advantages of built-in gain and fast read-out. However, radiation hardness remains a problem, reduced effective boron doping concentration (acceptor removal) after hadron irradiation that dramatically reduces LGAD gain. We propose a new LGAD process flow that allows for creation of a very steep boron profile in the multiplication region, reducing the fractional acceptor removal and resulting performance degradation. The new LGAD process flow requires a low temperature silicon-silicon wafer bonding process, which is currently under development. TCAD process simulations are used to demonstrate feasibility of the new structure, and TCAD device simulations are used to characterize LGAD performance before and after irradiation.