1. Pixel Sensors for the Mu3e Detector Dirk Wiedner on behalf of Mu3e February 2015 09.02.2015 1Dirk Wiedner PSI 2/15

2. Tracker Requirements High rates: 10 8 μ/s for Phase I Good timing resolution: 20 ns Good vertex resolution: ~200 μm Excellent momentum resolution: ~ 0.5 MeV/c 2  Extremely low material budget:  1x10 -3 X 0 (Si-Tracker Layer)  HV-MAPS spectrometer  50 μm thin sensors 09.02.2015 Dirk Wiedner PSI 2/152

3. HV-MAPS 09.02.2015Dirk Wiedner PSI 2/153 H igh V oltage M onolithic A ctive P ixel S ensors HV-CMOS technology Reversely biased by Ivan Perić I. Perić, A novel monolithic pixelated particle detector implemented in high- voltage CMOS technology Nucl.Instrum.Meth., 2007, A582, 876 P substrate N well NMOSPMOS

4. HV-MAPS 09.02.2015Dirk Wiedner PSI 2/154 H igh V oltage M onolithic A ctive P ixel S ensors HV-CMOS technology Reversely biased ~60V o Charge collection via drift  Fast <1 ns o Thinning to < 50 μm possible by Ivan Perić I. Perić, A novel monolithic pixelated particle detector implemented in high- voltage CMOS technology Nucl.Instrum.Meth., 2007, A582, 876 P substrate depletion layer N well -60V ~9μm

5. HV-MAPS 09.02.2015Dirk Wiedner PSI 2/155 H igh V oltage M onolithic A ctive P ixel S ensors HV-CMOS technology Reversely biased ~60V o Charge collection via drift  Fast <1 ns o Thinning to < 50 μm possible by Ivan Perić I. Perić, A novel monolithic pixelated particle detector implemented in high- voltage CMOS technology Nucl.Instrum.Meth., 2007, A582, 876

6. HV-MAPS 09.02.2015Dirk Wiedner PSI 2/156 H igh V oltage M onolithic A ctive P ixel S ensors Integrated readout electronics o Pre-amplifier o Digital readout Discriminator Time stamp and address Zero suppression by Ivan Perić I. Perić, A novel monolithic pixelated particle detector implemented in high- voltage CMOS technology Nucl.Instrum.Meth., 2007, A582, 876

7. MuPix Requirements 09.02.2015 Dirk Wiedner PSI 2/157 S/N >20 Efficiency >99% 20ns resolution <250-400 mW/cm 2 <100μm resolution 50μm thickness +Full digital readout +2x2 cm 2 size Trade-off between requirements

8. Test beams 09.02.2015Dirk Wiedner PSI 2/158 Four test beam campaigns in 2014 : o February DESY o June PSI o July PSI o October PSI DESY test beam with EUDET telescope (TB22) o Efficiency o Space resolution o Time resolution

9. MuPix Telescope 09.02.2015Dirk Wiedner PSI 2/159 MuPix4 and MuPix6 Four planes Thin sensitive area o 50 μm MuPix sensor o 25 μm Kapton foil  0.6‰ of X 0 High rate capability o >1 MHz hit rate o LVDS links to FPGA Time resolution <17ns

10. MuPix Telescope 09.02.2015Dirk Wiedner PSI 2/1510 MuPix4 and MuPix6 Four planes Thin sensitive area o 50 μm MuPix sensor o 25 μm Kapton foil  0.6‰ of X 0 High rate capability o >1 MHz hit rate o LVDS links to FPGA Time resolution <17ns

11. Setup DESY Test-Beam 09.02.2015Dirk Wiedner PSI 2/1511 Beam-line T22 o up to 6 GeV electrons Aconite telescope MuPix4 prototype Setup from Ivan Perić

12. Efficiencies 09.02.2015Dirk Wiedner PSI 2/1512 >99.5% efficiency o 5 GeV electrons o 45° angle o Individual pixel thresholds  Threshold tune from pixel efficiencies in previous test beam No dead pixels MuPix4 efficiency

13. Sub-Pixel Efficiencies 09.02.2015Dirk Wiedner PSI 2/1513 Chip folded back to 4 x 4 pixel area Resolution limited Overall high efficiency No pixel substructure (within resolution) MuPix4 sub-pixel efficiency

14. Spatial Resolution 09.02.2015Dirk Wiedner PSI 2/1514 Pixel size 80 μm x 92 μm Measured track residuals: o RMS x = 28 μm o RMS y = 29 μm Compatible with: o Single cell resolution + o Telescope pointing resolution (~16 μm) Pixel residuals

15. Time Stamps 09.02.2015Dirk Wiedner PSI 2/1515 MuPix4 prototype External Gray counter o At 100 MHz Time stamp recorded by MuPix4 sensor o For each pixel Time resolution O(17 ns) o Non-negligible setup contribution Time resolution of pixels

16. Time over Threshold vs Time Stamps 09.02.2015Dirk Wiedner PSI 2/1516 Time of particle hit measured with o Comparator output and FPGA sampling o Internal edge detector: Time Stamp Very good agreement ToT vs time stamps Comparator rising edge [2.5ns] Time Stamp [2.5ns]

17. Thinned Sensors 09.02.2015Dirk Wiedner PSI 2/1517 Wafers thinned: o MuPix4 thinned to 50μm o MuPix7 thinned to 50, 62, 75 and 250μm Good performance of thin chips o In lab o In particle beam MuPix4 thinned to 50μm

18. S/N vs Temperature TemperatureS/N at HV=-1V S/N at HV=-70V 24°C24.537.0 70°C21.031.5 09.02.2015Dirk Wiedner PSI 2/1518 S/N decreases with temperature Effect small for MuPix4 Pulse shape temperature dependence small Pulse shape vs temperature MuPix4 S/N vs temperature MuPix4 30°C 60°C

19. MuPix2 Performance 09.02.2015 Dirk Wiedner PSI 2/1519 S/N >20 Efficiency >99% 20ns resolution <250-400 mW/cm 2 <100μm resolution 50μm thickness MuPix2 80μm >86% ≥21.5  S/N and efficiency shown for same settings ? ≤17μm

20. MuPix4 Performance 09.02.2015 Dirk Wiedner PSI 2/1520 S/N >20 Efficiency >99% 20ns resolution <250-400 mW/cm 2 <100μm resolution 50μm thickness MuPix4 ?  Digital readout 50μm ≥31.5 ≤16.6ns >99.5% ≤29μm

21. MuPix6 Performance 09.02.2015 Dirk Wiedner PSI 2/1521 S/N >20 Efficiency >99% 20ns resolution <250-400 mW/cm 2 <100μm resolution 50μm thickness MuPix6 >94% >10  Digital readout ≤15.5ns 250μm ≥ 223 mW/cm 2 ≤70μm

22. MuPix7 Performance 09.02.2015 Dirk Wiedner PSI 2/1522 S/N >20 Efficiency >99% 20ns resolution <250-400 mW/cm 2 <100μm resolution 50μm thickness MuPix7 +Full digital readout ? ? ? 50μm ≈300 mW/cm 2 >10

23. MuPixX Requirements 09.02.2015 Dirk Wiedner PSI 2/1523 S/N >20 Efficiency >99% 20ns resolution <250-400 mW/cm 2 <100μm resolution 50μm thickness MuPixX +Full digital readout +2x2 cm 2 size

24. Prototype Performance PrototypeThicknessSpatial resolution Power/area mW/cm 2 Time resolution Eff.S/N MuPix280μm≤17μm?Not implemented >86%≥21.5 MuPix450μm≤29μm?≤16.6ns>99.5%≥37 MuPix6250μm<70μm≥223≤15.5ns≥94%>10 MuPix750μm, 62.5μm, 75μm ?≈300??>10 09.02.2015 Dirk Wiedner PSI 2/1524  Trade-off between requirements  Measurements limited by set-up and operation conditions

25. Roadmap MuPix7 o First fully integrated digital readout State-machine Fast serial data output o DESY test beam in March Efficiency and S/N Spatial and time resolution At <250-400mW/cm 2 MuPix8 if necessary o Fix MuPix7 bugs o Reduced pin count for flex print integration 09.02.2015 Dirk Wiedner PSI 2/1525

26. Roadmap MuPix7 o First fully integrated digital readout o DESY test beam in March MuPix8 if necessary o Fix MuPix7 bugs o Reduced pin count for flex print integration MuPix9 o Engineering run o ≥1x2 cm 2 size  Build Mu3e phase Ia with MuPix9 09.02.2015 Dirk Wiedner PSI 2/1526

27. Summary HV-MAPS technology o Makes thin silicon pixel detectors possible MuPix sensor prototypes o Rapid development o 50μm thin o <250-400mW/cm 2 o Efficiencies 99.5% o S/N >20 o Timing resolution O(17ns) 09.02.2015 Dirk Wiedner PSI 2/1527

28. Outlook Ongoing chip prototyping o MuPix7 just back from fabrication Integrated full digital logic Fast serial output Large area prototype planned for 2015 o ≥200 mm 2 active area o Engineering run o Base for module level integration and o Mu3e Phase 1A 09.02.2015 Dirk Wiedner PSI 2/1528

29. Backup Slides 09.02.2015Dirk Wiedner PSI 2/1529

30. Chip Prototypes 09.02.2015Dirk Wiedner PSI 2/1530 180 nm HV-CMOS Pixel matrix: o 42 x 36 pixels o 30 x 39 μm 2 each Analog part working well MuPix2 Ivan Perić ZITI

31. Chip Prototypes 09.02.2015Dirk Wiedner PSI 2/1531 Pixel matrix: o 40 x 32 pixels o 92 x 80 μm 2 each Analog part working Digital part under development o Bug in pixel on/off MuPix3 Ivan Perić ZITI

32. Chip Prototypes 09.02.2015Dirk Wiedner PSI 2/1532 Pixel matrix: o 40 x 32 pixels o 92 x 80 μm 2 each Analog part o Smaller pixel capacitance o Temperature tolerance Digital part o External state machine o Parallel data output o Zero time-stamp and address bug MuPix4 Ivan Perić ZITI

33. Chip Prototypes 09.02.2015Dirk Wiedner PSI 2/1533 Pixel matrix: o 40 x 32 pixels o 103 x 80 μm 2 each Analog part o Second pre-amplification stage Digital part o Zero time-stamp and address bug fixed MuPix6 Ivan Perić ZITI

34. Chip Prototypes 09.02.2015Dirk Wiedner PSI 2/1534 Pixel matrix: o 40 x 32 pixels o 103 x 80 μm 2 each Analog part o Second pre-amplification stage Digital part o Internal state machine o High speed serial data output MuPix7 Ivan Perić ZITI

35. Prototype Overview PrototypeActive AreaFunctionalityBugsImprovements MuPix11.77 mm 2 Sensor + analog Comparator “ringing” First MuPix prototype MuPix21.77 mm 2 Sensor + analog Temperature dependence No ringing MuPix39.42 mm 2 Sensor, analog, dig. bad pixel on/off,First digital readout MuPix49,42 mm 2 Sensor, analog, dig. Time-stamp + row address for 50% of pixels only Digital readout and timestamp, temperature stable MuPix610.55 mm 2 Sensor, analog, dig. None so farRemoved zero time-stamp and address bug MuPix710.55 mm 2 Sensor, analog, dig., fast serial out ?Fast serial data output 09.02.2015 Dirk Wiedner PSI 2/1535

36. Sensor + Analog + Digital 09.02.2015 Dirk Wiedner PSI 2/1536

37. Analog Electronics MuPix 09.02.2015 Dirk Wiedner PSI 2/1537

38. Residuals from Track Based Alignment 09.02.2015 Dirk Wiedner PSI 2/1538 Alignment for runs of HV-scan with MuPix telescope

39. Spatial Resolution 09.02.2015Dirk Wiedner PSI 2/1539 Pixel size 80 μm x 92 μm Measured track residuals: o RMS x = 28 μm o RMS y = 29 μm Compatible with: o Single cell resolution + o Telescope pointing resolution (~16 μm) √ (80 2 /(12)+16 2 ) μm = 28 μm √ (92 2 /(12)+16 2 ) μm = 31 μm Pixel residuals

40. Temperature Dependence 09.02.2015Dirk Wiedner PSI 2/1540 MuPix4 prototype Latency measurement o LED pulse to… o Pixel discriminator output Setup in oven o Temperature between 23°C and 70°C Readout through FPGA  Very little temperature dependence O(10ns)  Within resolution of setup

41. Timewalk 09.02.2015Dirk Wiedner PSI 2/1541 Latency o Difference of rising edge: Tile detector pulse - Time over Threshold vs Time over threshold signal Latency vs ToT Latency [2.5ns] ToT [10ns]

42. Pulse Shape vs. Power 09.02.2015 Dirk Wiedner PSI 2/1542 MuPix6

43. Thin vs. thick MuPix 09.02.2015Dirk Wiedner PSI 2/1543 MuPix2 early prototype Thick die 600µm Thin die 80µm Comparison of latency Pixel to pixel variations dominate Latency for thick and the thinned MuPix2 chip for different pixels

44. Charge collection 09.02.2015Dirk Wiedner PSI 2/1544 Charge collection has two components: o Drift o Diffusion 1650±17e - expected for 55 Fe Signal amplitude subject to shaping o Fast tail cancellation removes diffusion component by Ivan Perić I. Perić, A novel monolithic pixelated particle detector implemented in high- voltage CMOS technology Nucl.Instrum.Meth., 2007, A582, 876