1. TimePix / InGrid Problems and solutions Yevgen Bilevych Amsterdam 28.01.2013

2. 8’’ TimePix wafer 107 single chips Thickness 725 µm Surface materials: - Aluminum (aluminum oxide) - Silicon nitride - Silicon oxide

3. TimePix chip 14111  m 16120  m 256 x 256 pixels 20  m 10  m CHIPEDGE Column 0 Column 1 Column 2Column 3Column 4 Column 251Column 252Column 253 Column 254Column 255 CHIPEDGE 55  m 20  m 28.3  m 48.22  m 57.7  m Pixel Row 255 Pixel Row 254 Pixel Row 253 Pixel Row 1 Pixel Row 0 Detector Guard Ring Row Snake Top Row Snake Bottom Row

5. Main technological steps for the formation of structure TimePix / SU-8 / Al grid 4. Formation of structure “support” / grid 1. Formation of protection layer 2. Deposition of spacer material 3. Deposition of the Grid material

8. Wafer surface quality inspection W0058 EW5MWBX

9. Wafer surface quality inspection W0059 EU5MWDX

10. Wafer surface quality inspection W0060 E85MWZX

11. Wafer surface quality inspection W0061 E15MVPX

12. Polyimide mask Microsystems HD 4100 polyimide - negative tone, solvent developed, photodefinable polyimide Steps: Spinning Baking Exposition Development Silicon nitride deposition Chemical activation of polyimide Stripping Advantage: Silicon technology compatible Perfect alignment No residuals Disadvantage: Temperature sensitive process Time consuming process mechanical scratching of bonding pads

13. Oxford 80 (PECVD) PECVD Plasma enhanced chemical vapor deposition Silicone oxide or silicone nitride formation Plasma power max 600 W at 187.5 kHz, max 300 W at 13.56 MHz plasma frequency Substrate temperature 100 up to 400 °C Layers contain hydrogen

14. just deposited Si x N y “chemically activated polyimide”

16. - C - O Bisphenol A Novolak epoxy oligomer SU-8 photoresist composition : - Gamma Butyrolactone 22-60% - Up to 10 % Triarylsulfonium / Hexafluoroantimonate Salt (3.3% for SU-8/50) - Propylene Carbonate 1-5% - Epoxy Resin 35-75% SU-8 - epoxy-based negative photoresist R1 O CHCH 2 + H + R1 OH CH CH 2 + + R1 O CHCH 2 - H + R1 O CH CH 2 R1 O CH CH 2 SU-8 crosslinking mechanism

17. SU-8 layer map

18. Al layer Sputtering system Leybold Z660 12345678910111213141516171819202122232425 xxxxxxxxxxxxxxxxxxxxxx DC 50%, no sputter etching, 30 sec – the deposition time for every sputtering run, + cooling delay Total thickness: ~ 800 nm

19. deposition of Al layer Chip SU-8 photoresist aluminum SU-8 column protection layer Chip Pixel pad Cross-linked SU-8 photoresist

20. Development of SU-8 1.Acetone 2.Acetone:IPA:H 2 O (1:1:2) 3.Acetone:IPA:H 2 O (1:1:1) 4.Acetone:IPA (1:1) 5.Microstrip 6001 6.H 2 O 7.IPA 8. Acetone 9.Drying in the air

21. Standard development

22. Extra cleaning

23. O 2 plasma cleaning

25. O 2 plasma cleaning (long time)

27. IZM-5 started: W0062 (4  m Si x N y ) and W0063 (8  m Si x N y ) Modified InGrid (mInGrid) - started Summary W0058 EW5MWBX () in process W0058 EW5MWBX (4  m Si x N y ) in process W0059 () broken W0059 EU5MWDX (4  m Si x N y ) broken W0060 E85MWZX () in process W0060 E85MWZX (8  m Si x N y ) in process W0061 E15MVPX ()cleaning W0061 E15MVPX (8  m Si x N y ) requires the cleaning