Speaker
Description
We proposed a novel APD array with very high detection efficiency also in inter pixel gap regions to achieve nearly 100% fill factor. The APDs operate in proportional mode at low or moderate gain. By applying a fully depleted reach-through structure light entrance side and electronics side are kept separated. In contrast to common APD arrays where the gain drops to 1 or less within inter pixel gaps the avalanche process is sustained in the gap regions as well.
A non structured boron doped multiplication region (MR) extends over the entire array . Parasitic early breakdown at the n+ pixel edges caused by electric field peaks near to convex doping shapes is in our approach suppressed by a n-doped layer, called field drop region (FDR), located directly beneath the n+ pixels. The positive space charge of this fully depleted layer causes a reduction of the electric field to a non critical level when it reaches the n+ edges. The FDR gets depleted by the negative MR space charge preventing pixel shortage.
We have completed a first prototyping on 450μm thick p-type float zone wafers to demonstrate the feasibility of the concept. The prototype design contains small pixel and strip arrays for eta-plot measurements. We will present a description of the operating principles and comparison of the first measurements with simulations. By modifications of implantation parameters and reduction of wafer thickness the concept can by adapted for fast timing applications. For the next production a multi project wafer run is planned where
| Type of presentation (in-person/online) | online presentation (zoom) |
|---|---|
| Type of presentation (scientific results or project proposal) | Presentation on scientific results |
