Speaker
Description
We present here an evaluation of the high-rate suitability of AC-LGADs (also named Resistive Silicon Detectors RSD) that can be made with great segmentation for the charge collection while maintaining a 100% fill factor. This is achieved by employing un-segmented (p-type) gain layer and (n-type) N-layer, and a di-electric layer separating the metal readout pads. The design allows great flexibility in the choice of the geometry of the metal readout pads, both in terms of pitch and size. The high spatial precision is achieved by using the information from multiple pads, exploiting the intrinsic charge sharing capabilities of the AC-LGAD provided by the common N-layer. It depends on the location, and the pitch and size of the pads.
We tested the performance of AC-LGAD of several manufacturers with focused IR-Laser scans directed alternatively at the read-out side on the front and the bias side on the back of the AC-LGAD, and in charged particle beam tests. This allows to investigate the performance as a function of the following detector parameters: sheet resistance and termination resistance of the n-layer, thickness of the isolation di-electric, doping profile of the gain layer, pitch and size of the readout pads and the bulk thickness. TCAD simulations of the sensors are compared with the experimental results.
We use the data to evaluate the limitations high-speed readout ASICs can expect from high-flux charged particles and X-rays and from constraints of power consumption in the readout chain.
