1. G.Villani jan. 071 CALICE pixel Deep P-Well results Nwell 16 μm x 16 μm P-well 17 μm x 17 μm Collecting diodes 3.6 μm x 3.6 μm Bias: NWell 3.5V Diodes: 1.5V 50 μm x 50 μm pixel size P-well contact ground Hit points

2. G.Villani jan. 072 CALICE pixel Deep P-Well results ≈ 144 mV ≈ 202 mV ≈ 9.5 μm Epitaxial layer potential well V V/cm μmμm μmμm Diode F(z) top

3. G.Villani jan. 073 278 e - Diodes / 9e - NW/ 93 ns CALICE pixel Deep P-Well results 1 pixel results Charge collected (e - ) 803 e - Diodes / 28e - NW / 55 ns Collection time (ns) Diodes NW e-e-

4. G.Villani jan. 074 ConclusionsConclusions The barrier created by the Deep P-Well helps to reflect charge away from the central N-Well: major improvement in charge collection compared to non Deep P-Well process (however, the Deep P-Well extends down to ≈ 3 μm into the epitaxial layer, thus reducing the central active region). Collection time below 200 ns. Next step: P-Well guard ring around the pixel to further improve charge collection Smaller diodes simulations (proposed: 1.8 μm) Final layout simulation CALICE pixel Deep P-Well results

5. G.Villani jan. 075 CALICE pixel Deep P-Well results P-Well guard ring around each pixel