Yevgen: We have finished today with the polishing of cross-section for Medipix chip covered with silicon nitride by the using of polyimide mask. Please find in the attachment the images. Images (i.e. structure and thickness) are very similar to old ones made on the TimePix chip from square 3x3, which I sent before. So, I hope, the properties are the same too. I have sent Harry several pieces for the resistivity measurement, but I have no results yet.

Fred: it looks if the cracks have disappeared right now, although some vague straight lines are still visible at the boundary of the pad. But at least the SiN seems to make contact everywhere.

1) Could you tell me what you did to get another result as with IZM-2, or did you simply repeat the same procedure?

2) We should compare this result with the pictures Martin Fransen made at the edge of a broken TimePix. Could you also break this MediPix wafer to see whether the wafer still breaks at the boundary of the pixel pad or not?

Martin Fransen: These pictures look much better. But it still worries me a bit that I still can see a line going from the bottom all the way to the top, which means that there must be somekind of boundary effect there all the way through. Maybe this can be tested by operating one of those samples with ingrid/micromegas at a point at which discharges occur (maybe this can be done in the same run as measuring the layers resistance). The discharges should all be less than a few nC when quenched successfully.