UC Santa Cruz

We propose a new silicon sensor design capable of ultra fast (10's of ps) detection for experi- ments measuring time of flight (ToF) signals. The new design will couple fast readout with the current precise spatial resolution (10's of um) of silicon pixels. Charge multiplication via impact ionization is exploited to mitigate the loss of signal from the new detectors, which are necessarily thin to shorten carrier collection times. A study of charge multiplication in 300 um pad diodes manufactured at CNM Barcelona is presented and results are compared with simulations from a commercial TCAD software package. Observed gain factors are measured to be between 3 and 5, demonstrating proof of principle for charge multiplication in planar silicon sensors.