1. International DEPFET Workshop Stefan Rummel; MPI for Physics 1 Results from harsh X-Ray irradiation Stefan Rummel MPI for Physics – Halbleiterlabor International Workshop on DEPFET Detectors and Application Heidelberg 12.09.09

2. International DEPFET Workshop Stefan Rummel; MPI for Physics 2 Outlook ● Overview of the previous Irradiations ●Measurement program / Setup ●Results ●Outlook

3. DEPFET collaboration meeting, Aachen 12-13.02.2007 Stefan Rummel; MPI for Physics What happened up to now… (Talk 2007 Aachen) ●Single pixel structures with 6 micron gate length ●Using the single-pixel setup, with current based readout ●Characterization with respect to: Electric characteristics Leakage current Spectroscopic performance D1 D2 S G1 G2G2 Cl PXD4-10 MO2PXD4-5 M05PXD4-2 J14 TypeProtons @ 30MeVNeutrons @ 1-20MeVGammas - Co60 Dose1.2 * 10 12 n/cm²1.6 * 10 11 n/cm² 913kRad 1MeV n equivalent3*10 12 2.4*10 11

4. RD07 conference, June 27-29, 2007 - Florence Stefan Rummel; MPI for Physics 4 Electrical characteristics

5. International DEPFET Workshop Stefan Rummel; MPI for Physics 5 Setup / Measurement program ●DEPFET MATRIX fully biased while irradiation with clocked clear ●Irradiation stepwise with evaluation of  Characteristics Sub threshold slope Threshold voltage Gm  Threshold voltage of the parasitic CCG transistor  Clear-Clear isolation ●Statistics of four transistors ●Irradiation facility: X-Ray generator with Umax=80kV, 180kRad/h

6. Setup International DEPFET Workshop Stefan Rummel; MPI für Physik 6

7. International DEPFET Workshop Stefan Rummel; MPI for Physics 7 Results – Threshold voltage shift ●At 8 MRad 14V threshold voltage shift – compatible with measurements with Co60 ●Annealing at RT around 2.5V ●Dispersion in Vthr increases with dose - > Student in Karlsruhe will evaluate 96 transistors

8. International DEPFET Workshop Stefan Rummel; MPI für Physik 8 Spectroscopic performance Unbestrahlt: τ=10µs T=RT ENC noi = 2.1e - 7.8MRad X-Ray τ=10µs T=RT ENC noi = 4.6e - Leakage current in the pixel ~40 fA ( 10-22fA unirradiated) DEPFET works very well after 8MRad!

9. Proton irradiation ●Irradiation of 128² Matrix at the cyclotron in Karlsruhe  p irradiation up to 10^11 p/cm² 10MeV  Matrix fully biased Utilizing the poly-bias resistors in PXD5 ●Matrix is still in the fridge – waiting for the S3B system for final measurements... International DEPFET Workshop Stefan Rummel; MPI for Physics 9

10. International DEPFET Workshop Stefan Rummel; MPI for Physics 10 Conclusion ● DEPFET matrix is working very well after 8MRad  No significant detoriation of gq  No Problems with Clear-Clear isolation  Leakage current ~40 fA ● Good spectroscopic resolution ● Parameter spread due to irradiation will be investigated further ● Noise Spectrum will be evaluated with improved Setup in Milano (10MHz) soon ● Following questions need to be answered:  Inhomogenity of radiation?  Impact of inhomogenous irradiation to the efficiency S/N? Thanks to Karlsruhe for providing the irradiation facility and the dosimetry!

11. Backup International DEPFET Workshop Stefan Rummel; MPI for Physics 11

12. Backup – Evaluation of THR shift International meetion DEPFET app. In HEP Stefan Rummel; MPI for Physics 12

13. Inhomogenities International meetion DEPFET app. In HEP Stefan Rummel; MPI for Physics 13

14. Inhomogenities ●Assuming a spatial inhomogenity Δ, so the dose varies between dose – dose*(1+Δ) ●Calculating Dispersion= Uthr(dose*(1+Δ))- Uthr(dose) International meetion DEPFET app. In HEP Stefan Rummel; MPI for Physics 14