25.2.2003Sensor meetingF. Hartmann 1 Status report St & HPK plus add. Scratch tests. IEKP –...
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25.2.2003 Sensor meeting F. Hartmann 1 Status report St & HPK Status report St & HPK plus add. Scratch tests. plus add. Scratch tests. IEKP – University of Karlsruhe Frank Hartmann
25.2.2003Sensor meetingF. Hartmann 1 Status report St & HPK plus add. Scratch tests. IEKP – University of Karlsruhe Frank Hartmann
25.2.2003Sensor meetingF. Hartmann 1 Status report St & HPK
plus add. Scratch tests. IEKP University of Karlsruhe Frank
Hartmann
Slide 2
25.2.2003Sensor meetingF. Hartmann 2 QTC (sensors from JAN
& FEB) Optical inspection of KA-Set 10 &11 (33/35)
Electrical results of KA-Set 10/1 W5B (8/8) KA-Set 10/2 W5B (13/13)
KA-Set 11/1 W6B(5/10) KA-Set 11/2 W6B(4/4) KA-Set H5 W1TID(3/37)
Some high IV I-t Some currents are improving with time MANY sensors
at the IV limit Possible explanation for the high IV and
discrepancy of CMS & ST measurements.
25.2.2003Sensor meetingF. Hartmann 4 2 Sensors class C
3021102318502130211023752820 IV OK! 2 rejects!
Slide 5
25.2.2003Sensor meetingF. Hartmann 5 KA Set S10 (21 sensors
W5B)
Slide 6
25.2.2003Sensor meetingF. Hartmann 6 KA Set S10 ----
global
Slide 7
25.2.2003Sensor meetingF. Hartmann 7 KA Set S11 (9/14 sensors
W5A)
Slide 8
25.2.2003Sensor meetingF. Hartmann 8 KA Set S11 ----
global
Slide 9
25.2.2003Sensor meetingF. Hartmann 9 Comparison of Datas For 17
sensors no data available ! (~50% data still missing!!!!!!) Good
agreement for pinholes, shorts and Rpoly! Ileak & CaC not
measured by ST Add. defective strips have scratches! no add.
Pinholes due to scratches! Higher current @ 450V due to scratches!
QTC & ST agree on IV up to the additional ~linear~
increase!
Slide 10
25.2.2003Sensor meetingF. Hartmann 10 Same IV up to soft strip
breakdown First strip Second strip
25.2.2003Sensor meetingF. Hartmann 12 I-t @ 450V 1. 2. 10A 5 A
7 A 5 A Saturation not yet reached
Slide 13
25.2.2003Sensor meetingF. Hartmann 13 I-t @ 550V Min not
reached! 12 A 8 A
Slide 14
25.2.2003Sensor meetingF. Hartmann 14 I-t @ 550V over night
30211223972812
Slide 15
25.2.2003Sensor meetingF. Hartmann 15 Improvements of IV e.g.
30211023752813 I-t (~10 min) between each IV-curve !
Slide 16
25.2.2003Sensor meetingF. Hartmann 16 IV-problem 5 from 6
sensors improved, but they needed ~20 min or longer to reach the
specified limit! each sensor has a few high leaky strips! leaky
strips ~ IV ( few strips drive IV) EACH leaky strip is scratched !
Attention: standard test with I-t would had have jected 6 instead
of 1
25.2.2003Sensor meetingF. Hartmann 20 Solving/Explaining the
problem!?!??? Clear correlation between IV and leaky strips and
scratches on sensors observed! No IV-breaks on Minisensors !
Handling ! Scratch test: Scratchtest on minisensors to reproduce
effect Needle Pencil (2B) screwdriver
Slide 21
25.2.2003Sensor meetingF. Hartmann 21 Scratches on Minisensor
Soft scratches with probe needle Carbon residues of pencil
Slide 22
25.2.2003Sensor meetingF. Hartmann 22 Deep scratches on
Minisensor Not-so-SOFT scratches with screwdriver
Slide 23
25.2.2003Sensor meetingF. Hartmann 23 IV of ST-minisensor
x3
Slide 24
25.2.2003Sensor meetingF. Hartmann 24 ILeak (regard strips
8-15) A few single strips show high leakage current!
Slide 25
25.2.2003Sensor meetingF. Hartmann 25 Ileak ramps on scratched
strips x 70 All ramps on screwdriver scratched minisensor! The ramp
behavior is similar to the global IV!
Slide 26
25.2.2003Sensor meetingF. Hartmann 26 Correlation strip current
IV Correlation strip current IV Undamaged minisensor @ 400V: Ileak
~ 0,2nA x 192 strips ~ 35nA IV ~ 38nA Damaged minisensor @ 400V:
Ileak damaged strips ~ 55nA Ileak all ~ 100nA IV ~ 120nA High IV
behavior is driven by some leaky strips !
Slide 27
25.2.2003Sensor meetingF. Hartmann 27 Similar defect in CDF
sensors Defect in the p+ layer!! BUT: scratches do not effect p+ (
no pinholes!)
Slide 28
25.2.2003Sensor meetingF. Hartmann 28 Idiel on scratched
Minisensor Pinholes should be here ! Effect is located in the Al
layer, above the oxide!
Slide 29
25.2.2003Sensor meetingF. Hartmann 29 Summary of scratch-test
Scratches increase individual strip leakage current Some few leaky
strips drive high IV Hard mechanical force necessary to damage
sensor! ALL unscratched minisensors show GOOD IV ! ALL leaky strips
are scratched, but not all scratched strips are leaky ! Pinholes???
no pinholes produced in scratch-test no big differences between
data of ST and QTC (w.r.t. pinholes) Effect is located in the Al
layer, not the p+ layer CMS sensors have metal strip
overhang!!!!
Slide 30
25.2.2003Sensor meetingF. Hartmann 30 HPK W1TID qualification
PQC fine, but quite low depletion voltages BTC OK Masks: postponed
-- should be done in Vienna, cause CMM breakdown in KA QTC: fine,
but quite low depletion voltages! Very low total leakage currents.
3/27 sensors measured (no single strip failure)
Slide 31
25.2.2003Sensor meetingF. Hartmann 31 KA SET H5 (3/37
W1TID)
Slide 32
25.2.2003Sensor meetingF. Hartmann 32 KA SET H5 --- global
