15-17 December 2003ACFA workshop, Mumbai - A.Besson R&D on CMOS sensors Development of large CMOS Sensors Characterization of the technology without epitaxy R&D on fast sensors R&D on fast sensors Summary Summary Auguste Besson on behalf of IRES/LEPSI (Strasbourg, France): M. Deveaux, A. Gay, G. Gaycken, Y. Gornushkin, D. Grandjean, S. Heini, A. Himmi, Ch. Hu, K.Jaaskelainen, H. Souffi-Kebbati, I. Valin, M. Winter, G. Claus, C. Colledani, G. Deptuch, W. Dulinski (M6/M8 DAPNIA: Y. Degerli, N. Fourches, P. Lutz, F.Orsini)

15-17 December 2003ACFA workshop, Mumbai - A.Besson2 R&D strongly depends on the fabrication technology  Need to explore the different fabrication processes Key parameters: –Epitaxial layer ( ≳ 5µm) –Feature size ( ≲ 0.35µm) –Leakage current –Metalisation (3-5 metal layers) –Etc. Main features of CMOS Sensors 20-40µm Preamplifier (1 in each pixel) Thermal diffusion of electrons High (p-well) Moderate (Epitaxial layer) High (subtrate) P doping Free electron in the conducting band Potential in the diode region Particle path Charge collecting diode Develop. of large CMOS Sensors Caracterization of the technology without epitaxy R&D on fast sensors (SOC) R&D on fast sensors (SOC)

15-17 December 2003ACFA workshop, Mumbai - A.Besson3 Main streams of the R&D Beam tests at CERN-SPS in 2003 (120 GeV/C  - ) Beam tests at CERN-SPS in 2003 (120 GeV/C  - )  M5 (reticle size)  M4 and SUC2 (no epitaxy) Laboratory testsLaboratory tests  M6 (fast data treatment)

15-17 December 2003ACFA workshop, Mumbai - A.Besson4 Large CMOS sensors (1) M1/2 (20 µm pitch) –  sp ~ 1.5/2.2 µm with 14/4 µm epitaxial –  1 ≳ 99% ;  2 ~ 98.5% Mimosa 5 –AMS 0.6 µm process –Reticle size  19.4 x 17.4 mm 2 –4 submatrices –512 x 512 pixels (/each of 4 submatrices) Performances –6 wafers (6”) fabricated in 2001 –3 wafers thinned down to 120 µm   det ~ 99% ;  sp ~ 2 µm;  ~ 0.3 % Mimosa 5 layout

15-17 December 2003ACFA workshop, Mumbai - A.Besson5 3-T large CMOS sensors (2) Beam tests at SPS (2003) –3 sensors Performance uniformity tests –Between sub-matrices and sensors –Diode size comparisons Signal/noise seed pixel Big diode (5x5 µm 2 ) Signal/noise seed pixel Small diode (3x3 µm 2 ) Total Charge in N pixels

15-17 December 2003ACFA workshop, Mumbai - A.Besson6 Large CMOS sensors (3) STAR experiment : extension of the Vertex detector (2006) –Charm physics  small radius, granular and thin detector –2 layers of pixels  ≳ 1000 cm 2 ; R layer1 ≳ 2 cm; R layer2 ≲ 4 cm M5 performances are close to STAR requirements  Started a collaboration with LBL and BNL What to improve ? read out time ~ 24 ms  < 20 ms sensor thickness ~ 120 µm  ≳ 50 µm leakage current (because of room T) yield (not crucial)  First mimo-STAR prototype in summer 2004 (TSMC 0.25 µm tech.)

15-17 December 2003ACFA workshop, Mumbai - A.Besson7 No epitaxial layer prototypes Properties (M4) –AMS 0.35 µm without epitaxial layer  low doping substrate  increases µ e –120 GeV/c  - SPS beam tests  eff ≳ 99.5% ;  sp ~2.5 µm (20 µm pitch) Application to the European Project for biomedical imaging  SUCIMA (SUC2) –beam monitoring and dosimetry –less granularity needed  eff ≳ 99.9% ;  sp ~5-6 µm (40 µm pitch) Submission of Mimosa 9 with AND without epitax. layer in a single AMS 0.35 µm batch (January 2004)  Fabrication processes with epitaxial layer are not mandatory ! M4 Total charge in N pixels M4: Signal/Noise in seed pixel

15-17 December 2003ACFA workshop, Mumbai - A.Besson8 R&D on fast sensors (1) R&D on fast sensors (1) M1-M5  1M pixels read out in 1-10 ms FLC  1 st VD layer must be read out in  s – potentially tremendous data flow: e.g. 15 bits/pixels, t~25  s  500 Gbits/s/10 6 pixels! –main goal: fast signal treatment AND data compression integrated in the sensor  Fast // read-out of short columns Different prototypes with different signal treatment: –M6 (with DAPNIA): tests with 55 Fe in 2003,  individual pixels and discri work fine, but large spread of pixel caracteristics (pedestal, noise, gain ?) –M7: available, tests in –M8 (with DAPNIA): submitted in Nov., tests in 2004 (beamstrahlung)

15-17 December 2003ACFA9 R&D on fast sensors (2) R&D on fast sensors (2) Mimosa 6 (IRES-LEPSI/DAPNIA)  0.35 µm MIETEC techno.  30 columns of 128 pixels r.o. in //  Amplification (5.5) and Correlated Double Sampling integrated in the pixel  5 MHz effective r.o. freq.  Discriminator (DAPNIA) on chip periphery  P diss ~ 500 µW per col. and frame r.o. cycle Mimosa 6 28 µm Distribution of signal amplitude (1pixel) Conversion gain Calib. Peak 5.9 keV Charge storage Capacitor (90 fF) AC coupling capacitor (50 fF)

15-17 December 2003ACFA workshop, Mumbai - A.Besson10 Summary Large sensors (M5) (1M pixels, AMS 0.6  m ) –ready to be used for a real detector –2 nd fabrication (23 wafers) with a better yield expected –thinning down to ≲ 50 µm in progress  application to extension of STAR Vertex detector in 2006 No epitaxial layer sensors (M4, SUC 2) –validated for m.i.p. detection (eff ≳ 99.5%,  sp ~2,5  m) –fits industrial CMOS fabrication tendency Fast response sensors (M6, M7, M8) – studies: fab. techno., charge collection system, signal treatment architecture  read out speed, efficiency, zero sup., power diss. etc. 2003/2004 schedule –Large sensors: M5-B tests  yield, achieve thinning –M ⋆ 1  available in summer 2004, tests in autumn –Fast sensors: M7 and M8 tests –M9 (with and without epitaxy)  submitted in january 2004 –charge collection studies  ionising radiation tol.