Summary of CMS 3D pixel sensors R&D Enver Alagoz 1 On behalf of CMS 3D collaboration 1 Physics Department, Purdue University, West Lafayette, IN US CMS upgrade week and workshop, FNAL, 9 October 2011

SINTEF 3D pixel sensors for CMS – Lab tests – Beam test results (2010) – Irradiation FBK 3D pixel sensors for CMS – Lab test results – Beam test results (2011) For unirradiated and irradiated sensors Beam test results for CMS CNM 3D sensors (2011) – Unirradiated Summary Outline Preliminary

3D vs planar ionizing particle 300µm n+ p+ e h depletion p-type p+ n+ 50µm p-type depletion PLANAR: 3D: p+ and n+ electrodes are arrays of columns that penetrate into the bulk Lateral depletion Charge collection is sideways Superior radiation hardness due to smaller electrode spacing: - smaller carrier drift distance - faster charge collection - less carrier trapping - lower depletion voltage Higher noise Complex, non-standard processing

SINTEF 3D PIXEL SENSORS

SINTEF 3D Wafers B5 : 280µm substrate thickness B2-16 : 200µm substrate thickness Wafer B5 Wafer B2-16 P-type wafers include sensors for: - CMS - ATLAS - MediPix MediPix

3D CMS pixel layouts 2E Configuration 4E Configuration n+ (readout)p+ (bias) 100 μm 150 μm The edge is an electrode! Dead volume at the edge is few microns!

SINTEF 3D Plaquette Al fixture VHDI Adhesive ROC Sensor Bump bonds Support wafer HV bias wirebond Au plated Ceramic Bias pad

IV measurements T = 21 °C

Noise T=21 °C Unable to measure noise at V bias < 40V for 4E sensors

Beam test results 2E_WB5_2 March 2010 beam test data T sensor ≈ 16 o C V bias = -40V

Irradiation study Sensors irradiated in Los Alamos National Lab with 800 MeV protons (1MeV neutron equivalent factor ~1) fluences: 1, 2.2, and 7.2x10 15 n eq /cm 2 with 11% beam uncertainty at room temperature no bias applied Annealed at 80 °C for 1 hour All ROCs were dead (reason not known)

FBK 3D PIXEL SENSORS

FBK 3D sensors FBK processed full 3D sensors for CMS Sensors with guard rings Three geometries: 1E,2E,4E 14 sensors per wafer Thickness 200 microns Sensors received from ATLAS 08 batch 1E _4 1E _3 1E _6 2E_ 11 1E 2E 4E CMS 100 μm 150 μm p+ n+ 1E (1x n+) 2E (2x n+) 4E (4x n+) E: Electrode

FBK 3D plaquette Sensors bump bonded to PSI46v2 ROC in SELEX (In bumps) 9 sensors received in 2011: 1E (6x), 2E (1x), 4E (2x) Wire bonded and assembled on FPIX plaquettes PSI test setup is used to fully calibrate FBK sensors in lab ROC calibration Noise Charge collection with Sr-90 source Purdue setup for lab testing FBK sensor plaquette Sensor ROC Bump bonds VHDI Base plate Adhesive Wire bond Bias wire

IV measurements

Noise tests T=21 °C Single pixel SCurve 2D noise map Noise distribution Error function fit Gaussian fit Higher noise due to long pixel on the sensor edges

Noise T=21 °C 4E 2E 1E

Charge collection T=21 °C Sr-90 source: 1 mCi, E β = ΜeV Random trigger used Landau convoluted Gaussian fit 1 Vcal = 65 e- MP = 14 ke-

Charge collection T=21 °C

Beam test results (1E_2) V bias = -15V : 20 o tilt Preliminary Beam spot 98.5% efficiency σ total ~ 40 μm All clusters 62% size 1 pixel 37% size 2 pixels Unirradiated sensor

Beam test results (2E_9) V bias = -5V : 20 o tilt Preliminary Beam spot 94.6% efficiency σ total ~ 40 μm All clusters 77% size 1 pixel 22% size 2 pixels Unirradiated sensor

Beam test results (1E_4) V bias = -15V : 0 o tilt Preliminary Beam spot 84.5% efficiency σ total ~ 40 μm All clusters 99% size 1 pixel 1% size 2 pixels Irradiated sensor (1x MeV p/cm 2 )

CNM 3D PIXEL SENSORS

CNM 3D sensors Columns etched from opposite sides of substrate Columns don't pass through full thickness Hole aspect ratio 25:1 10µm diameter, 250µm deep P- and N-type substrates, 285µm thick Giulio Pellegrini et al (CNM)

Beam test results (12-3_62A) V bias = -15V : 0 o tilt Preliminary Beam spot 93.4% efficiency σ total ~ 45 μm All clusters 99% size 1 pixel 1% size 2 pixels Unirradiated sensor

Summary - SINTEF All sensors were wire bonded and assembled at Purdue Lab characterization tests: IV results: breakdown > -100 V All performed well but with higher noises vs CMS planar sensors Good bump bond quality Testbeam: Testbeam at FNAL in 2010 Data taken at several voltages and thresholds Charge collection performed Irradiation: 6 sensors were irradiated to fluences 1,2.2, and 7.2x10 15 n eq /cm 2 No lab characterization tests done due to dead ROCs Next: Waiting for more 3Ds without support wafer

Summary - FBK All 9 sensors were wire bonded and assembled at Purdue Lab characterization tests: IV results: breakdown at V bias < 40 V Performed well with noises compatible with CMS planar pixels Good bump bond quality Charge collection with Sr-90 source for all sensors Testbeam: Testbeam performed at FNAL in October 2011 Data taken at several voltages and angles Irradiated sensors (Φ = 1x MeV p/cm 2 ) tested and worked fine Next plans: Sensors will be irradiated at Los Alamos (Φ = x MeV p/cm 2 ) Post-irradiation testbeam at FNAL in 2012 Finalize analysis of testbeam 2011 data

BACKUP SLIDES

BEAM CONTROL ROOM DUT PIXEL DETECTORS SCINTILLATORS 3.7V POWER SUPPLY ACELLERATOR CLOCK CLOCK AND TRIGGER DISTRIBUTION FNAL testbeam (2011) 120 GeV protons No B field Meson Area FBK 3D plaquette

Cold setup Purdue cold test setup Environmental chamber -35 °C < T < 200 °C Humidity control Works with CAPTAN and PSI DAQ systems Good for sensor IV measurements and ROC calibrations at cold Chamber control is very old No PC control Cold setup for irradiated 3D sensor calibration

Irradiation study (SINTEF) Leakage current related damage rate α ΔΙ[A] = α  V  Φ[n eq /cm 2 ] where V is sensor active volume α average(2E) = 2.8x A/cm vs α RD48 = 3.99x A/cm α average(4E) = 4.5x A/cm 4E α values are higher than 2Es Full depletion not reached due to early breakdown 2E & 4E sensor currents at the highest Φ are ~1 mA