1. First Proton Irradiation of CMS Sensors W. de Boer, A. Dierlamm, A. Furgeri, E. Grigoriev, F. Hartmann, F. Hauler, L. Jungermann, Ch. Piasecki

2. Some facts to remember for the next slides Data is preliminary Measurements and evaluation was done in 4 days only including the weekend  some plots can be arranged in a better way and the data is incomplete! (sorry!!!) The biasing was done with conductive rubber  residuals on AC pads sometimes gives contact problems We used the testing of the teststructures to train personal After irrad.: Strip scan for ST at Vbias=900V (it was stable) The evaluation is not complete!

3. Materials Hamamatsu Full Sensor (W6b 4919-39) Thickness: 500  m Resistivity: 4.6 k  cm Hamamatsu teststructures (same batch no. 35-41) –Have to look up all other parameters according to the HPK tables ST Full Sensor (04439218) Thickness: 500  m Resistivity: 5.1 k  cm

4. Simulated LHC conditions with respect to surface damage! Vbias

5. Irrad. Assembly

6. IV and CV on both Sensors

7. Strip Parameters on Ham. Sensor

8. Interstrip capacitance of HPK sensor (1 neighbour) 100 fF

9. Strip Parameters on ST Sensor

10. IV and CV on Ham. TS

11. Strip Parameters on Ham. TS

12. Comparison: Diode vs. Minisensor

13. High fluence ( 2.5x10^14 n eq /cm 2 ) FS Ham.@ 1V (AC & bias) TS H39 @ 1V TS H38 @ 12V TS H37 @ 100V TS H35 & H36 @ 0V TS H40 @ 100V (only bias) 33MeV

14. Low fluence ( 1,5x10^14 n eq /cm 2 ) FS ST @ 1V TS ST26 @ 1V TS H41 @ 0V

15. Fluence estimate (preliminary) Leakage current on TS H39 diode at -8±1°C: I(-8°C) = 5  A Leakage current at 20°C (I(T)=I 0 *T 1.5 *e -1.2eV/kT ): I(20°C)= (860 ± 190)  A Volume of diode is 72 mm 3 => I(20°C)/V = (11.9 ± 2.6)mA/cm 3 => Fluence is about (3.0±0.6)e14 n eq /cm 2 (  =4e-17A/cm) Leakage current on TS H41 I(-9°C) = 1.5  A Fluence is about (1.1±0.3)e14 n eq /cm 2 Hamamatsu: ST:

16. Leakage Current on Ham. Diode after Irrad. with high Fluence

17. Leakage Current on Ham. Diode after Irradiation with low Fluence

18. CV on Ham. Diode after Irradiation

19. CV on Sensors after Irradiation

20. IV for Sensors after Irradiation

21. Coupling Capacitance on ST Sensor after Irradiation

22. Poly Resistance on ST Sensor after Irradiation

23. Leakage Current ST FS after irrad. 1-4nA before irrad.

24. Other Paramters on ST Sensor Interstrip Capacitance (one neighbour): Before Irradiation3.5 pF After Irradiation3.6 pF Interstrip Resistance: Before Irradiation > 10G  –No definite numbers after irrad

25. Strip Leakage Current on Ham. Sensor after Irradiation

26. Poly Resistance on Ham. Sensor after Irradiation 300V, -13°C 160V

27. Interstrip Capacitance (one neighbour) vs. Bias Voltage after Irradiation

28. Strip Leakage Current on TS after Irradiation

29. Coupling Capacitance on TS after Irradiation

30. Poly Resistance on TS after Irradiation

31. Interstrip Capacitance on TS after Irradiation (2 neighbours) Some bad contacts due to residuals of conductive rubber!?!?!

32. Interstrip Resistance on TS after Irradiation (very preliminary)

33. Depletion Voltage and Fluence

34. Conclusion: Procedure for the production Evaluation on minisensor and FS only Irradiation with protons is feasible with small bias voltage  near to final LHC condition We have to evaluate the irrad. sensor with higher Vbias The IQC in Karlsuhe is ready with some possible improvements, learned at this system test level Some additonal measurments and x-ray studies are ongoing and helpfull for the surface damage understanding but are not essential for the approval of an ingot!

35. End of irradiation

36. „I-t“

37. Backside of HPK sensor

38. First GCD measurements

39. CMS-GCD-Structures Diode Gate Diode Gate Diode

40. Measurement of the CMS square GCD structure and Rose structure in literature Some non-understood points. KA Rose

41. GCD after proton irradiation

42. GCD Summary Proton irradiation has shown that bulk leakage current is much higher than interface currents at least at full dose and is therefore negligible. (see also NIM A444 (2000) 605-613) What about effects of type inversion? However further studies at Karlsruhe are possible by using the KA X-Ray source.

43. Bias contacts