1. Update of CMS Process Quality Control Sensor Meeting, CMS TK Week, 9.4.2003, CERN Florence Anna Macchiolo Carlo Civinini Mirko Brianzi Strasbourg Jean-Charles Fontaine Jean-Laurent Agram Vienna Thomas Bergauer Margit Oberegger

2. Anna Macchiolo, Sensor Meeting, 9th April 20032 Overview  Conclusions from the inter-calibration process  Software update  Results from the last measured batches Karlsruhe 5 HPK W1 Tid Vienna 11-12-13 HPK W4 Perugia 15-16-17-18-19-23 HPK IB1 / IB2 Pisa 61-62-63 HPK IB1 / IB2 Vienna 8-9 STM W7A / W7B Perugia 22-24-25-26-27 STM OB1 / OB2  Wafer resistivity in HPK  Stability of our results

3. Anna Macchiolo, Sensor Meeting, 9th April 20033 Inter-calibration Results: Good agreement in all the measurements except Aluminum resistivity Inter-strip resistance Circulation of 15 Test-structures Vienna Strasbourg Florence Strasbourg Florence Vienna Florence Vienna Strasbourg

4. Anna Macchiolo, Sensor Meeting, 9th April 20034 Aluminum resistivity Differences in the measured aluminum resistivity in the three labs are of the order of 20-25 % The corrections we have to apply to take into account additional resistive contributions (from the probe-card, cables, switching matrix) are of the same order of the Al resistances Further investigations are going on Al  in m  per square

5. Anna Macchiolo, Sensor Meeting, 9th April 20035 Inter-strip resistance Since we are measuring currents of few pA the spurious currents introduced by the probe-card make a big difference. Our measurements must be intended as lower limits on the real resistance We are able to detect the cases where the specification Rint > 1 G  is not respected Rint in M 

6. Anna Macchiolo, Sensor Meeting, 9th April 20036 Software update The acquisition software has been made faster by:  Decreasing the LCR meter integration time for the CV on diode and on MOS, where we do not need extreme precision  Optimization of the LCR driver, cutting useless initialization and configuration at every step The time needed for the full analysis of a standard moon has decreased (for example in Florence it takes now 23 minutes instead of 48). The analysis VIs have changed to remove infinite loops in the cases where the fit fails

7. Anna Macchiolo, Sensor Meeting, 9th April 20037 Results from last STM sets measured  are of good quality low metal resistivity low V fb All the PQC measurements are inside specifications with the exceptions shown in the following … Perugia 22-24-25-26-27 Vienna 8-9

8. Anna Macchiolo, Sensor Meeting, 9th April 20038 Perugia 24 (STM): defects on the surface of many structures Early breakdown of one mini-sensor with the surface heavily damaged

9. Anna Macchiolo, Sensor Meeting, 9th April 20039 Perugia 25 (STM) 3 structures from Perugia 25 have low depletion voltage Wafer resistivity around 10 K  per cm Our request is 3.5 <  <7.5 K  per cm The surface current measured on the GCD is very high for one structure but Vfb is inside limit. First time we don’t see the correlation between the two problems. Only one sensor has been shipped from this batch. We suggested to reject the corresponding sensor.

10. Anna Macchiolo, Sensor Meeting, 9th April 200310 Perugia 15-16-17-18-19-23 Pisa 61-62-63 Karlsruhe 05 Vienna 11-12-13 Results from last HPK batches 100 < Vdepl < 250 V Almost perfect for the PQC qualification. The only notable problem is the depletion voltage, much lower than our specification

11. Anna Macchiolo, Sensor Meeting, 9th April 200311 HPK bulk resistivity … but last HPK batches have a substrate resistivity over 4 Kper cm Our original request on wafer resistivity is 1.5 <  < 3.0 K per cm HPK has asked to enlarge the range to 1.25 <  < 3.25 K per cm since the wafer supplier cannot assure narrower specifications Depletion voltage measured on the diode Compiled will all data in DB Series production

12. Anna Macchiolo, Sensor Meeting, 9th April 200312 STM bulk resistivity Depletion voltage measured on the diode Inside our specifications 3.5 <  < 7.5 K per cm

13. Anna Macchiolo, Sensor Meeting, 9th April 200313 Dependence of PQC variables upon production time (1) All the Vfb values outside our limits come from production weeks 209 and 210 Compiled with all the data inserted in the DB up to now STM HPK

14. Anna Macchiolo, Sensor Meeting, 9th April 200314 Before week 220: resistivity around 27 m  per square. Strip width at the mask nominal value of 10  m After week 220: resistivity in the range 15-23 m  per square. From the strip profile it’s difficult to disentangle the contribution to the strip height of the passivation oxide and of the metal layer but we can clearly observe: Increase of 1  m in the strip height Decrease of about 2  m in the strip width Sheet Structure: Al strip profile measured with a Scanning Near-field Optical Microscope (SNOM) at LENS - european laboratory for non-linear spectroscopy Fluctuations in the Al resistivity probably due to the fact that the numbers of squares used in the calculation was not correct (STM communicated the new numbers in October 2002). 10  m 7.7  m 2.7  m 1.6  m Metal resistivity in STM

15. Anna Macchiolo, Sensor Meeting, 9th April 200315 10  m 7.7  m 2.7  m 1.6  m 2.7  m 1.6  m 20  m 18  m Metal strips in the Sheet Structure (STM) 302 104 203 870 17 :  = 26.5 m  per square 302 104 238 602 09 :  = 20 m  per square

16. Anna Macchiolo, Sensor Meeting, 9th April 200316 Dependence of PQC variables upon production time (2) 0.5 < Cint < 1.3 pF Cac > 16 pF Cac > 18 pF STM HPK