FBK 3D CMS pixel sensors preliminary lab measurements E. Alagoz 1, A. Krzywda 1, D. Bortoletto 1, I. Shipsey 1, G. Bolla 1, and G. F. Dalla Betta 2, M. Boscardin 3, S. Kwan 4 1 Physics Department, Purdue University, West Lafayette, IN USA 2 NFN and University of Trento 3 FBK, Via S. Croce Trento – Italy 4 Fermilab, Batavia, IL USA CMS Tracker Upgrade Plenary, 22 July 2011

3D vs planar FBK 3D pixel sensors for CMS – Readout chip (ROC) characterization tests – Noise tests – Charge collection tests FBK 3D pixel sensors testbeam plans at FNAL Summary and outlook Outline

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

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

FBK 3D sensors 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 3D testing FBK sensor plaquette

IV measurements

Lab V = -5 V : T=21 °C A sample summary report of a psi46v2 ROC calibration

Noise tests T=21 °C Single pixel noise curve 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 FBK_4E_13 has relatively lower charge collection Gain calibration is problematic

Summary & outlook 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 – 1E_3 sensor has irregular charge distributions at V bias > 25 V ROC calibration needs to be optimized Testbeam plans: Testbeam at FNAL in October 2011 Irradiation will be soon after the testbeam Post-irradiation testbeam at FNAL in February 2012

Czech Technical University, Fermilab, Purdue University, SINTEF, SLAC, University of Hawaii, University of Manchester 3DC

BACK UP SLIDES

BEAM CONTROL ROOM DUT PIXEL DETECTORS SCINTILLATORS 3.7V POWER SUPPLY ACELLERATOR CLOCK CLOCK AND TRIGGER DISTRIBUTION FNAL testbeam 120 GeV protons No B field Plastic protection Cooling tubes Meson Area Purdue 3D plaquette