8 July 1999A. Peisert, N. Zamiatin1 Silicon Detectors Status Anna Peisert, Cern Nikolai Zamiatin, JINR Plan Design R&D results Specifications Status of work in the labs Work to be done Conclusions

8 July 1999A. Peisert, N. Zamiatin2 R&D results: radiation hardness Irradiations: –Protons - Cern PS: fluence ( )  p/cm 2 detectors biased and cooled to -5  C –neutrons - reactor in Dubna: fluence 0.6x  n/cm  n/cm 2 room temperature, no bias irradiation statistics

8 July 1999A. Peisert, N. Zamiatin3 Preshower: Si sensors Detectors produced in Russia, Taiwan, Greece and India Extensive R&D: ~50 detectors irradiated with n and p electrical tests: measure I-V, C-V  full depletion and break down voltage Elma detector, 60x60 mm 2

8 July 1999A. Peisert, N. Zamiatin4 Design total surface 63x63 mm 2 from a 4” wafer, single sided polished thickness 300 ±20  m 32 strips at a pitch of 1.9 mm, length 60 mm 4 guard ring system for electric protection on the n + -side windows in Al and passivation (PSG) layers for the light tests by LED or laser big windows (1000x2000 µm²) on passivation for test by probe and small (100x100 µm²) for ultrasonic bonding single sided photo-litography process

8 July 1999A. Peisert, N. Zamiatin5 Quality control after manufacturing Electrical tests before irradiation by +20C –leakage current, breakdown voltage – capacitance vs voltage, full depletion voltage

8 July 1999A. Peisert, N. Zamiatin6 R&D results: radiation hardness Electrical tests –leakage current strip by strip at different bias voltages up to 500V at room temperature for non irradiated detectors –noise level strip by strip at different bias voltages at room temperature for non irradiated detectors –leakage current and noise strip by strip at -30C after irradiation up to 1000 V

8 July 1999A. Peisert, N. Zamiatin7 Leakage current strip by strip during irradiation, det.DS2

8 July 1999A. Peisert, N. Zamiatin8 R&D results: radiation hardness Electrical tests –leakage current vs temperature The current doubles every 7.1 o C

8 July 1999A. Peisert, N. Zamiatin9 R&D results: radiation hardness Electrical tests –leakage current vs time

8 July 1999A. Peisert, N. Zamiatin10 R&D results: radiation hardness Dynamic tests –SCT32 chip: 28 channels of preamplifiers (T p = 45 ns), shapers, analog data buffers and a multiplexer –detectors tested in a freezer at -30 o C to reduce the noise –typical ENC  3000 e - – 106 Ru  source + calibration pulses on 100 fF capacitor –signal normalized to charge collected from a non irradiated detector, 300  m thick, at 500 V

8 July 1999A. Peisert, N. Zamiatin11 R&D results: radiation hardness Full depletion voltage: CCE measurement V fd (CCE)

8 July 1999A. Peisert, N. Zamiatin12 R&D results: radiation hardness 1 k  cm Silicon

8 July 1999A. Peisert, N. Zamiatin13 R&D results: radiation hardness V fd (CCE) - V fd (CV)

8 July 1999A. Peisert, N. Zamiatin14 R&D results: radiation hardness Noise

8 July 1999A. Peisert, N. Zamiatin15 R&D continuation Test of irradiated detectors with m.i.p., running now in H2 –Si high precision, xy telescope  good track definition –measure: particles detection efficiency charge loss charge spread over adjacent strips

8 July 1999A. Peisert, N. Zamiatin16 Specifications (preliminary) k  n-type Silicon,, 300  m thick 4” wafers, polished on one side 63 x 63 mm 2 total surface, 32 strips, 1.9 mm pitch V br  V fd V or V br  250 V I fd  5  A, I  10  A at V fd V Maximum 1 strip with I = 1  A at V fd uniform noise at V fd V passivation cutting: negative tolerances (50  m)

8 July 1999A. Peisert, N. Zamiatin17 Status of work in the labs Dubna –detectors produced in Elma, Zelenograd –over 100 detectors produced for beam tests and R&D –very close and dynamic collaboration Dubna-Elma for R&D –production of 250 detectors starts in the fall Taiwan –first contacts with Preshower - December 1998 –detectors produced in Taiwan and Japan –multi-pattern design to study the geometrical parameters –6 batches of ~20 detectors each produced for beam tests and R&D –expecting new mask aligner (August) to make 63x63 mm 2 detectors –pre-production in 2000

8 July 1999A. Peisert, N. Zamiatin18 Status of work in the labs Greece –detectors produced at the Institute of Microelectronics, Demokritos –5 detectors produced, 3 irradiated –10 detectors, 60x60 mm 2 in August, more later –new mask aligner for 63x63 in October 99 –pre-production in 2000 India –3 batches on 2” wafers produced, V br  V –work on processing 4” wafers is in progress

8 July 1999A. Peisert, N. Zamiatin19 Future plans Continue R&D on a smaller scale –improved technology for back plane n + contact – deep oxygen diffused detectors –tests of detectors from Greece and India Detectors implementation in the Preshower –gluing: technology silver (from the conductive glue) activation after irradiation –cooling test with irradiated detectors (in progress)

8 July 1999A. Peisert, N. Zamiatin20 Conclusions Preshower detectors tested up to 2.3x10 14 n/cm 2 and 3.2x10 14 p/cm 2 –charge loss  20 % (at T p = 45 ns) –no significant noise increase detectors from Elma and Taiwan satisfy the specifications Greece and India need more R&D First 250 detectors (1m 2 ) will be produced in Elma in 1999 Results from the Preshower beam test with Pace presented in a separate talk