15-17 December 2003 ACFA workshop, Mumbai - A.Besson

R&D on CMOS sensorsR&D on CMOS sensors

• Development of large CMOS Sensors• Characterization of the technology without Characterization of the technology without

epitaxy epitaxy • R&D on fast sensorsR&D on fast sensors• SummarySummary

Auguste Bessonon 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 2003 ACFA workshop, Mumbai - A.Besson 2

• 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 SensorsMain features of CMOS Sensors

20-40µm

Preamplifier (1 in each pixel)

Preamplifier (1 in each pixel)

Thermal diffusion of

electrons

Thermal diffusion of

electrons

High (p-well)Moderate Moderate (Epitaxial (Epitaxial layer)layer) High (subtrate)

P doping

Free electron in the conducting band

Free electron in the conducting band Potential in the

diode region

Potential in the diode region

Particle path

Charge collectingdiode

Charge collectingdiode

• Develop. of large CMOS Sensors• Caracterization of the Caracterization of the technology without epitaxy technology without epitaxy • R&D on fast sensors (SOC)R&D on fast sensors (SOC)

15-17 December 2003 ACFA workshop, Mumbai - A.Besson 3

Main streams of the R&DMain streams of the R&DCHIP YEAR PROCESS EPITAXIAL PITCH METAL PECULIAR

mm mm

M1 1999 AMS 0.6 mm 14 20 3M thick epitaxy

M2 2000 MIETEC 0.35 mm 4,2 20 5M thin epitaxy

M3 2001 IBM 0.25 mm 2 8 3M deep sub-mm

M4 2001 AMS 0.35 mm 0 ! 20 3M low dop. Substrate

SUC 2 2003 AMS 0.35 mm none 40 3M low dop. Substrate (SUCIMA project)

M5 & M5B 2001/2003 AMS 0.6 mm 14 17 3M real scale 1M pixels

M6 2002 MIETEC 0.35 mm 4,2 28 5M col. // r.o. and integrated spars.

M7 2003 AMS 0.35 mm none 25 4M col. // r.o. and integ. spars. (photoFET)M8 2003 TSMC 0.25 mm 8 25 5M col. // r.o. and integrated spars.

• Beam tests at CERN-SPS in 2003 (120 GeV/C Beam tests at CERN-SPS in 2003 (120 GeV/C --)) M5 (reticle size)M5 (reticle size) M4 and SUC2 (no epitaxy)M4 and SUC2 (no epitaxy)

• Laboratory testsLaboratory tests M6 (fast data treatment)M6 (fast data treatment)

15-17 December 2003 ACFA workshop, Mumbai - A.Besson 4

Large CMOS sensors Large CMOS sensors (1)(1)• M1/2 (20 µm pitch)

sp ~ 1.5/2.2 µmwith 14/4 µm epitaxial 1≳ 99% ; 2 ~ 98.5%

• Mimosa 5– AMS 0.6 µm process– Reticle size

19.4 x 17.4 mm2

– 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; <gain>~ 0.3 %

Mimosa 5 layoutMimosa 5 layout

15-17 December 2003 ACFA workshop, Mumbai - A.Besson 5

33--T large CMOS sensors T large CMOS sensors (2)(2)

• Beam tests at SPS (2003)– 3 sensors

• Performance uniformity tests– Between sub-matrices and sensors– Diode size comparisons

Signal/noise seed pixelBig diode (5x5 µm2)

Signal/noise seed pixelBig diode (5x5 µm2)

Signal/noise seed pixelSmall diode (3x3 µm2)Signal/noise seed pixelSmall diode (3x3 µm2)

Total Charge in N pixelsTotal Charge in N pixels

15-17 December 2003 ACFA workshop, Mumbai - A.Besson 6

Large CMOS sensors Large CMOS sensors (3)(3)

• STAR experiment : extension of the Vertex detector (2006)– Charm physics small radius, granular and thin detector

– 2 layers of pixels ≳ 1000 cm2 ; Rlayer1 ≳ 2 cm; Rlayer2 ≲ 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)

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 2003 ACFA workshop, Mumbai - A.Besson 7

No epitaxial layer prototypesNo epitaxial layer prototypes• Properties (M4)

– AMS 0.35 µm without epitaxial layer low doping substrate increases µe

– 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 !

M4Total charge in N pixels

M4Total charge in N pixels

M4: Signal/Noise in seed pixelM4: Signal/Noise in seed pixel

15-17 December 2003 ACFA workshop, Mumbai - A.Besson 8

R&D on fast sensors R&D on fast sensors (1)(1)

• M1-M5 1M pixels read out in 1-10 ms

• FLC 1st VD layer must be read out in 25-50 ms

– potentially tremendous data flow: e.g. 15 bits/pixels, t~25 ms 500 Gbits/s/106 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 55Fe in 2003,

individual pixels and discri work fine, but large spread of pixel caracteristics (pedestal, noise, gain ?)

– M7: available, tests in 2003-04– M8 (with DAPNIA): submitted in Nov., tests in 2004

(beamstrahlung)

15-17 December 2003 ACFA 9

R&D on fast sensors R&D on fast sensors (2)(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 pixel5 MHz effective r.o. freq.Discriminator (DAPNIA) on chip peripheryPdiss ~ 500 µW per col.

and frame r.o. cycle

Mimosa 6Mimosa 6

28 µ

mDistribution of signal

amplitude (1pixel)Distribution of signal

amplitude (1pixel)

Conversion gainCalib. Peak 5.9 keV

Conversion gainCalib. Peak 5.9 keV

Charge storage

Capacitor (90 fF)

AC coupling capacitor (50 fF)

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SummarySummary• Large sensors (M5) (1M pixels, AMS 0.6 mm )

– ready to be used for a real detector– 2nd 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 mm)– 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.