CERN/MIC group X-ray irradiation system


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This page contains information and timetable of the X-ray irradiation system in the CERN PH department, ESE group. This facility is located at CERN, in building 14, room 5-002. It is accessible, upon request, to all users from the HEP community.

The X-ray irradiation system:

The system is composed of an X-ray machine (Seifert RP149), a semi-automatic wafer prober (Karl Suss PA200) mounting a thermal chuck of 8 inches from Digit Concept, a cooling element and a controller from Digit Concept to set and maintain the temperature of the chuck, a CCD camera, and a dry air system filtering and drying the air from the compressed air network to lower the dew point inside the irradiation cabinet. The irradiation system is installed inside a dedicated room (controlled area only accessible to owners of a personal dosimeter) where appropriate cooling is ensured by a powerful air conditioning system.

More information about the system, together with the most recent calibration curves, can be found in a document linked in the page "Calibration" (in the top menu of this page).

The system has been assembled to radiation test silicon integrated circuits for Total Ionizing Dose (TID) effects at different temperatures - from cryogenic to more than 100 degrees C. Temperatures approaching 0 degrees or below require a controlled dry atmoshpere inside the irradiation cabinet: the efficiency of this system has been tested down to -50C at the time of acquisition, but tests at -30C are routinely done where the DUT is kept at cryogenic temperature for several days without ice formation. The probe station, together with the CCD camera for alignment of the probe needles, allow for testing of wafers or unpackaged silicon devices.

Main characteristics:

bulletX-ray generator:
bullet X-ray tube using a Tungsten target (peak 10 keV)
bulletBeryllium window to seal the tube, thickness 0.25 mm
bullet Aluminum filter of 0.15 mm to ensure reasonably uniform dose rate in the DUT, that has to be exposed bare (no package, or unlidded package)
bulletCalibration performed with a Quantrad PIN diode, with a sensitive depth of 25 Ám
bullet Dose rate variable up to above 9Mrad/hour
bullet Diameter of the X-ray beam around 3-4 mm in the high dose rate configuration
bulletMaximum power supply voltage: 50 kV
bulletMaximum tube current: 60 mA
bulletTube cooled with circulating water
bulletLaser pointer allows to align DUT with X-ray beam center
bulletIrradiation cabinet:
bulletLarge irradiation cabinet (120 x 132 x 106 cm) with lead-glass front windows
bulletTube can move vertically (manual) and in X-Y directions (with motor controlled via RS232)
bulletWafer prober:
bulletSemi-automatic probe station Karl Suss PA200
bullet 8 inches chuck with temperature control
bulletA CCD camera replaces the microscope, and moves together with the X-ray tube
bulletThermal chuck:
bullet8 inches thermal chuck on PA200
bulletAdaptor for packaged chips availble (DIL packages)
bullet Temperature range: -50 to +200oC

 

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Last modified: 31 March 2014