SINTEF Wafers We studied two wafers. Wafer #9 and wafer #24. Most of the measurements were done on wafer #9. Road map of the wafer would be helpful. We guessed some of the structures by looking at it. Still clarification from designers is essential.

Rolf’s Devices Purdue Devices Diode cluster JHU Devices BTev Devices N + side A1 - pixel # 1,2,3,6,7 F1 - pixel # 4 This asymmetric structure will help to distinguish N and P side easily Note : Pixel 6 (A1) is broken for this device

Measurement A We measure the total leakage current. In some design 1st guard ring is connected with the diode, in other cases it is not. In any case we connect the ammeter with the diode only. N N+N+ P+P+

Summary

Design 8 different types of Pixel design and 4 different types of Guard Ring design Some of them have metal on pixel some don’t

Design A Design B Design C Design D Design E Design F Design G Design H Pixel Design

Design I Design II Design III Design IV Diode Guard Ring Design

Except Pixel 7, AI has high breakdown.

Design AIII and AI lack consistency.

Design B: they break down between V

For other designs we have only one pixel array per design. ==>No statistics Design F and G, best two designs spotted out of CSEM wafer has also high breakdown voltage and low leakage current in SINTEF wafer. Measurement

Performance V breakdown > 750V for 5 devices (all with metal on top) V breakdown > 300V for 16 devices V breakdown < 300 for 10 devices but 5 of them have breakdown near 300V Current per unit area after depletion is 3-6 nA/cm^2