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

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 Dirk Wiedner PSI 2/152

HV-MAPS Dirk 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

HV-MAPS Dirk 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

HV-MAPS Dirk 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

HV-MAPS Dirk 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

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

Test beams Dirk 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

MuPix Telescope Dirk 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

MuPix Telescope Dirk 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

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

Efficiencies Dirk 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

Sub-Pixel Efficiencies Dirk 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

Spatial Resolution Dirk 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

Time Stamps Dirk 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

Time over Threshold vs Time Stamps Dirk 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]

Thinned Sensors Dirk 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

S/N vs Temperature TemperatureS/N at HV=-1V S/N at HV=-70V 24°C °C Dirk 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

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

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

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

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

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

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??> Dirk Wiedner PSI 2/1524  Trade-off between requirements  Measurements limited by set-up and operation conditions

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 < mW/cm 2 MuPix8 if necessary o Fix MuPix7 bugs o Reduced pin count for flex print integration Dirk Wiedner PSI 2/1525

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 MuPix Dirk Wiedner PSI 2/1526

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

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 Dirk Wiedner PSI 2/1528

Backup Slides Dirk Wiedner PSI 2/1529

Chip Prototypes Dirk Wiedner PSI 2/ 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

Chip Prototypes Dirk 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

Chip Prototypes Dirk 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

Chip Prototypes Dirk 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

Chip Prototypes Dirk 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

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 MuPix mm 2 Sensor, analog, dig. None so farRemoved zero time-stamp and address bug MuPix mm 2 Sensor, analog, dig., fast serial out ?Fast serial data output Dirk Wiedner PSI 2/1535

Sensor + Analog + Digital Dirk Wiedner PSI 2/1536

Analog Electronics MuPix Dirk Wiedner PSI 2/1537

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

Spatial Resolution Dirk 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

Temperature Dependence Dirk 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

Timewalk Dirk 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]

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

Thin vs. thick MuPix Dirk 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

Charge collection Dirk 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