Recent progress on MIMOSA sensors

1
Recent progress on MIMOSA sensors

• A.Besson, on behalf of

IReS/LEPSI M. Deveaux, A. Gay, G. Gaycken, Y.
Gornushkin, D. Grandjean, F. Guilloux, S. Heini,
A. Himmi, Ch. Hu, K.Jaaskelainen, M. Pellicioli,
H. Souffi-Kebbati, I. Valin, M. Winter, G. Claus,
C. Colledani, G. Deptuch, W. Dulinski, M.
Szelezliak (M6/M8 DAPNIA Y. Degerli, E.
Delagnes, N. Fourches, P. Lutz, F.Orsini)

• Fabrication technology
• Parameter optimization (pitch, T, diodes, etc.)
• Signal treatment and read-out speed
• Thinning
• Radiation tolerance

2
MIMOSA 9 (1)

• Main features
• Techno opto.
• Self Bias / Standard
• Pitch 20/30/40 ?m
• Small/large diodes (3/6 ?m)
• With/without epi.

0.96 mm
1.2 mm
3T, 40 ?m 32 x 32
SB, 30 ?m 32 x 32
5 x 5 ?m
Explore the different parameters
SB, 20 ?m 64 x 64
SB, 40 ?m 32 x 32
3
MIMOSA 9 (2)

• Beam test _at_ CERN-SPS (120 GeV/c ?-)

Charge (1 pixel) MPV 325
(25 pixels) MPV 870
(9 pixels) MPV 850
MPV 24
Self-Bias, Pitch 20 ?m, diode 6 x 6 ?m2
4
MIMOSA 9 (3)

• First comparisons
• SB with 20/30 ?m pitch eff 99.8
• Resolution 1.5 ?m _at_ 20 ?m pitch
• Analysis in progress
• Temperature
• Chip without epi.
• Hit selection
• optimization

Sp. Resolution SB, diode 3.4 x 4.3 ?m2
Noise (e-) vs Diode surface ?m2
5
Fast read-out architecture

• Different developments based on Mimosa 6
• VX DET layer 1-2
• Fast, column // readout, with hit selection
• VX DET layer 3-4-5
• Multiple scans of the whole detector within train
  (r.o. 200 ?s).
• Then read the samples between trains
• Integrate capacitors in each pixel (M7 and M8)
• Mimosa 7
• Features
• photoFET.
• 25 ?m pitch, No epi., 0.35 ?m, 64x16 readout in
  // with CDS
• Status
• Being tested
• Beam test in Oct.
• Mimosa 8 (with DAPNIA)
• Features
• 25 ?m pitch, 8 ?m epi., 0.25 ?m, 128x32 readout
  in // with CDS
• Signal discrimination
• Status

6
Thinning

• Mimosa 5 thinned down to epi. Layer (SUCIMA)
• Beam test. _at_ CERN
• S/N

M5-B thinned down
M5-B standard
7
MIMOSTAR

• STAR exp. upgrade 1st proto sent for fabrication
• Extension of the Vertex Detector (2 layers)
• Running conditions
• T amb. (higher leakage current). Readout time
  4ms
• Features
• TSMC 0.25 techno
• Based on M5
• Pitch 30x30 ?m2. 128x128 pixels
• Surface 4 x 5 mm2
• Subdivision in 10 groups of columns
• Pure analogic output. 10x10MHz output
• Status
• Expected back from fab. end Oct.

8
Radiation hardness

• SUC 1 (SUCIMA)
• Chip with 8 ? pixels design. 30 ?m pitch
• Goal study charge loss after irradiation (X-ray)
• Irradiation
• X-ray 500kRad and 1MRad
• Calibration with 55Fe
• Measure leakage current _at_ different T
• Being analysed
• Charge loss ? for some pixel designs
• Leakage current
• Next irradiation beam test
• M9 (X, n)
• M5 (n)

? Seems to stand 1 MRad
9
Conclusion and outlook

• Geometry
• Efficiency and resolution ok from 20 to 40 ?m
• New techno opto. AMS 0.35 ?m
• Epi. Layer may change
• Chip read-out architecture
• 2 research lines
• layer 1-2 r.o. speed
• Layer 3-4-5 storage capacitors
• 2 proto being tested
• Promising results
• Radiation hardness
• Studies in progress
• Evidence ? stand gt 0.5 MRad. Up to 1MRad.
• M9 (n,X), M5 (n)

10
Mimosa prototypes