Tests on Sintef/Standford IZM (Nov09) and AMS (May10) 17 Dec 2009 Alessandro Rovani, Claudia Gemme, Gianluca Alimonti, Nanni Darbo INFN Genova/Milano 17 devices IZM bumped received on Nov 16. FE electronic wafer AGD525X 8 devices AMS bumped received in May FE electronic wafer S789IUX
Selex Two Sintef wafers of the same batch bump-bonded last year at IZM have been bump-bonded at Selex –ATLAS FE-I3 and CMS assemblies flip-chipped –Dicing sensors was troublesome: dies detached from sticky tape used in the process. Diamond saw uses a “water” process during dicing. Selex claims they never had such problem in the past (~thousands of sensors handled for ATLAS Pixel) –Cut edge is very irregular from support wafer side, clean (~150µm from active edge) on bump side (see photos) –4+4 assemblies flipped sent to Genova this week: 5 put on single chip board and tested.
Wafer 1: B2-6 Received assemblies from Selex
Wafer 2: B4 Received assemblies from Selex
Diced assembly 150 µm
Bump side
Compare bump/back side Bump-side – Magnification = x200 Back-side – Magnification = x200 Left side Right side Front side does not show dicing damage. Is only support wafer damaged? Or impacts the sensor?
Sensor Wafer FEI3SensorLV 20V (e) B /12 ->68/5119 (no effect when blowing) NOT DONE (1V) B /11-> 69/ >0.36 (FAN)180 B /11-> 75/ > 4.4 (FAN)250 B /11 -> 66/ (no effect when blowing) NOT DONE (1V) B /11->66/14617,6NOT DONE (2V) B /11->70/ eGE B /11->66/15020NOT DONE (2V) B /21 -> 214/ >10.7 (FAN)Good dig, bad analog B /24-> 270/ > 0.29 (FAN)Good dig, bad analogBonn B /27->285/149Isteresi ( 1-7;3 -16)Good dig, bad analog B /12 -> 76/ > (FAN)400 eBonn B /11-> 71/ e but col 15,16,17 bad B /35->320/1514.1Good dig, bad analog B LV in short 0.40Not possible B /11 -> 66/ > 0.58 (FAN)400 e B /20->285/1501.7Good dig, bad analog B /11 -> 68/ > 0.62 (FAN)250 but xtalkGE SINTEF/IZM
General comments on IZM Almost all devices have high current on HV. As a 1MOhm resistance is between the PS and the DUT, a significant voltage reduction is expected in case of high current on the device. Some devices have unusually high LV currents (main on Analog supply): they work digitally but analog injection is bad. We have observed IV worsening in time after some handling or testing (difficult to track). We have also observed devices initially becoming bad in LV current consumption.. Never observed an improvement in time (also drying has no effect). Some devices work fine, even with high leakage current. However noise is relatively high and we just could tune one device at relatively high threshold.
Sensor Wafer FEI3SensorLV 20V (e) B Not loaded B /13020 B /5018Analog inj bad B Not loaded B Not loaded B /5320Analog inj bad B /13020 B / SINTEF/AMS All devices have high current on HV. As a 1MOhm resistance is between the PS and the DUT, a significant voltage reduction is expected in case of high current on the device. Some devices have unusually high LV currents (main on Analog supply): they work digitally but analog injection is bad.