Status on CMOS Sensors

1
Status on CMOS Sensors

• A. Besson, on behalf of

IReS Strasbourg G. Claus, C. Colledani, (G.
Deptuch), M. Deveaux, M. Dorokhov, W. Dulinski,
M. Goffe, D. Grandjean, F. Guilloux, S. Heini,
A. Himmi, Ch. Hu, K. Jaaskelainen, M. Pellicioli,
A. Shabetai, M. Szelezniak, I. Valin, M.
Winter (M8 CEA Saclay M. Besançon, Y. Degerli,
N. Fourches, Y. Li, P. Lutz, F. Orsini) (M11
Frankfurt S. Amar-Youcef)

• Specific aspects of a VD based on CMOS sensors
• Status of the main RD directions
• Plans for 2006

2
Specific aspects of the CMOS VD concept
ADC, sparsification
pixels

• Overall design a priori very similar
  
  to TESLA TDR concept (CCD)
• Basic characteristics
• Main RD effort

• 5 cylindrical layers
• R 15 60 mm
• surface 3000 cm2

support

• sensor thickness
• 25-50 ?m
• total number of pixels
• 300 millions
• Pmean 25 W
• (full detector
• 1/20 duty cycle)
• operated T gt 5o ?

? concentrated on achieving fast CMOS
sensors ? signal processing (sparsification)
integrated/chip
3
Status of the main RD directions

• Fast read-out in L1/L2 with // processing of
  columns
• Mimosa 8 (with Saclay) ? characterized in test
  beam. (See F.Orsinis talk)
• Multi-memory architecture (FAPS) in L3-L5
• Mimosa 12 ? tested in lab.
• Radiation hardness (Ionising damage) _at_ high TºC
• Mimosa 11 ? characterized in test beam.
• ? irradiated with 10 keV
  X-Rays up to 1 MRad.
• other on going activities
• Fabrication processes
• ADC
• Thinning
• Mimostar-2

4
// read-out architecture
5
// read-out architecture Mimosa 8

• Mimosa 8 (see F.Orsinis talk)
• Test in lab 55Fe results
• Pixel noise 15 e-
• CDS ending each col.
• ? Pixel-to-pixel dispersion 8 e-
• Test beam results (DESY, 5GeV e-)
• Analog part
• Charge ? 450 e- ? thin epi layer
• Typical noise ? 12-15 e-
• S/N (MPV) 8.5 - 9.5
• Digital part
• The discriminator works as expected
• efficiency / purity / multiplicity
• Next step ADC, rad. hardness, AMS 0.35 OPTO,
  speed

• - TSMC 0.25 ?m fab. process with 8 ?m epitaxial
  layer
• Pixel pitch 25 ?m
• 3 sub matrices with 3 diode surfaces
• 1.2 x 1.2 µm2
• 1.7 x 1.7 µm2
• 2.4 x 2.4 µm2
• 24 // columns of 128 pixels with 1 discriminator
  for each column
• 8 analogic columns

6
M8 digital Efficiency and fake rate
Efficiency ()
Temp. 20oC r.o. 40 MHz
Fake Hit rate / pixel / event
Average hit multiplicity (num of pixels in
cluster)
S/N(seed) cut gt 5.5 (? discri. threshold 5
mV) Contamination lt 5 x 10-5

• First sensor with integrated
• signal numerisation !
• Architecture to be extended with
• ADC for EUDET telescope

7
Multi-memory architecture
8
Multi-memory architecture (1)

• Mimosa 12 (MOSAIC-1)
• Layers 3-5.
• New prototype exploring various types
  dimensions of memory cells
• AMS-0.35 ?m techno
• 4 capacitors/pixel (35 ?m pitch)
• 6 sub-arrays with various MOS capa. 50, 100, 200
  fF
• Aim for minimal size capacitors providing
  satisfactory precision, depending on pitch -
  i.e. layer - ( 4.6 fF/?m2)
• Minimal size of capacitor 50 fF (see also CAP
  for BELLE)

9
Multi-memory architecture (2)

• 4 capacitors / pixel
• Calibration peak with 55Fe
• With sampling and read-out
• With direct read-out

tint 230 µs ? O(1 ms)
Standard pixel Without sampling Standard
pixel Without sampling Standard pixel Without
sampling
50 fF
100 fF
200 fF
Storage duration is critical
10
Radiation hardness
11
Radiation hardness (1)
SB
SF

• Mimosa 11 structures
• AMS 0.35 µm opto.
• 8 different sub-matrices
• Standard
• rad tol thin oxyde and guard ring
• Minimize leakage current
• Mimosa 11 test beam
• DESY, 5 GeV e-
• T 40 oC 700 µs (2.5 MHz)
• S/N (MPV) 24
• Eff 99,9 ? 0.05

p
p
p
n
P-Well
N-Well
P-epi
Standard (A0 sub 2)
Partially P doped
P poly filling
P poly filling
Partially P doped
SB
SF
n
p
p
n
p
N-Well
P-Well
P-epi
Rad hard (A3 sub 1)
12
Mimosa 11
10 keV X-ray

• (with S. Amar-Youcef, C. Müntz, J. Stroth.
  Frankfurt)

Temperature
-25 C
10C
40 C
0kRad
Noise (e-)
Standard structure
200 µs
500kRad
Integration time (ms)
Rad hard structure
4-pixel cluster 55Fe spectrum before (red) and
after (green) 1 Mrad of X-rays _at_40C (200 µs
integ. time)
Standard structure
Rad hard structure
13
Other on-going activities
14
Other on-going activities

• Fabrication process exploration
• AMS 0.35 µm opto.
• Excellent performances (M9, M11, M14)
• Epi. Layer 12 µm
• S/N 20-30 (MPV) ??det 99-99.9 ?sp
  1.5-2.5 ?m (20 ?m pitch)
• Will be used for EUDET
• TSMC 0.25 µm
• Typical cluster charge for MIP 450 e- ? Epi.
  Layer 6.5 µm
• ADC
• Wilkinson double ramp (4.5 bits)
• Succ. approx. 5 bits.
• LPC-Clermont full flash ADC
• LPSC-Grenoble semi-flash ADC
• Thinning (Mimosa-5)
• TRACIT company
• Thinning at 50 µm successful (mech.) ?
  electrical tests foreseen
• On going tests to thin down to 40 µm

15
MimoSTAR 2

• MIMOSTAR-2
• AMS 0.35 µm OPTO. 30 µm pitch
• 2 matrices 64 x 128, JTAG architecture
• Rad. hard structure (based on mimosa 11)
• Prototype for the MIMOSTAR 3 chip to be installed
  in STAR (2007)
• Mimostar 3 also to be used for the EUDET
  telescope demonstrator
• Ionising radiation tolerant pixel validated at
  temperature up to 40 oC
• No active cooling needed at int. time lt O(1 ms)

Efficiency vs Temp
S/N (MPV) vs Temp

• ?Test-beam results
• (DESY, 5 GeV e-)
• 2 r.o. time (2 and 10 MHz)
• ? 800 µs and 4 ms

(preliminary)
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Plans for 2006 and beyond

• Multi-chip engineering run in AMS 0.35µm opto.
• MIMOSTAR-3 512 x 256 pixels, 30 µm pitch, r.o.
  time 1.6 ms
• To be installed in STAR in 2007 (also for EUDET
  telescope demonstrator)
• MIMOSA-8 upgrade Larger size, rad hard, faster,
  smaller pitch, etc.
• ADC (4-5) bits
• Imager (ring like n-well, see P. Rehak_at_ Wildbad
  Kreuth)
• Next generation of multi-memory chip (M12 like)
• Opportunity for other contributions (e.g.
  CAP-Hawaï)
• Exploration of new technologies
• AMS 0.18 µm OPTO, etc.
• Thinning below 50 µm

17
Summary and Outlook

• Well established performances
• S/N, ?det, ?sp
• Rad. tolerance to neutrons, electrons and X-Rays
• Assessment of a well performing RD fabrication
  process
• AMS-035 ?m (opto and epi-free) ? very good
  perfo. even with 40 ?m pitch (L4)
• Most recent achievements
• M8 first prototype with discri. promising
  results.
• M11 radiation hardness up to 1MRad (if tint lt
  100 µs)
• M12 gt 50 fF capacitors seem mandatory
• Next important steps
• Multi-chip engineering run in AMS 0.35µm opto
• STAR ? EUDET demo.
• Fast column // sensor with digital output
  ?L1-L2, EUDET final
• ADCs (4-5 bits)
• More evolved multi-memory cell sensor adapted to
  L3-5
• Investigate characteristics of new fab. processes
  (e.g. AMS-0.18 ?m opto, etc.)

18
Mimosa 11
10 keV X-ray

• (with S. Amar-Youcef, C. Müntz, J. Stroth.
  Frankfurt)

Temperature
-25 C
10C
40 C
0kRad
20kRad
Standard structure
200 µs
500kRad
Rad hard structure
Noise (e-)
1000kRad
Integration time (ms)
19
M8 digital Hit multiplicity
20
Multi-memory architecture (1)

• Diode  self-bias 
• Couplage AC 50fF
• Ampli. Nmos G10
• 4 capacités de stockage
• Ampli. Source Follower

Cap 200 fF
Cap 100 fF

• Diode  self-bias 
• Couplage AC 50fF
• Ampli. Nmos G10
• 2 capacités de stockage  clamping  (CDS
  intégré)
• Ampli. Source Follower

Cap 50 fF

• Diode  self-bias 
• Couplage AC 50fF
• Poly-Poly
• Nwell - Poly
• Ampli. Pmos G7
• 4 capacités de stockage
• ( Cap 200 fF)
• Ampli. Source Follower

AC Poly - Poly
AC Nwell - Poly
Clamping