3D detectors at CNM

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3D detectors at CNM
Giulio Pellegrini, Celeste Fleta, Manuel Lozano,
Miguel Ullan
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ALCATEL 601-E

• -Deep RIE-ICP.
• Load-lock manual one 4 wafer
• SF6 etching
• C4F8 passivation
• Cooled mechanical clamping He-Ln2
• Possibility of Cryogenic etching.

SOI
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ALCATEL 601-E
Isotropic RIE
AFM tips
Anisotropic RIE
plasma
Cryogenic system
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Development of 3D technology

• Optimization of thick Photoresist deposition
• One year to optimize RIE for Deep Etching
• 40 wafers sacrificed for testing

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Deep RIE
Etch rate4.8µm/min Alpha91º
3µm holes
5µm hole
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Deep RIE
SiO2
?0.4 ?m
Damping0.8 ?m
Scalloping0.2?m
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Deep RIE

• 10 ?m holes
• 55?m pitch
• 80 minutes etching
• 300 ?m thick wafer
• Aspect ratio 241

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Polysilicon deposition
Spreading resistance
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Polysilicon deposition
Junction Depth660nm
Polysilicon Thickness2?m
top
bottom
Phosphorus diffusion Time80 min.
Temp.1050ºC
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Future work
Bump bonding to Medipix2 chip (Imaging, charge
sharing test) FE Atlas chip (radiation hard)
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Edgeless detectors

• INTAS project with CERN for the fabrication of
  next TOTEM detectors.

G. Ruggiero et al., Planar Edgeless Silicon
Detectors for the TOTEM Experiment, Nuclear
Science Symposium Conference Record, 2004 IEEE
Volume 2, 16-22 Oct. 2004 Page(s)922 - 924.
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Edgeless detectors-fabrication
Current Terminating Ring (CTR)
trenches
G.Pellegrini et al., Edgeless Detectors
Fabricated by Dry Etching Process, accepted for
publication in Nucl. Instr. and Meth A 2006.