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Noise in TOB modules and sensor Noise in TOB modules and sensor qualityquality

Noise in TOB modules and sensor Noise in TOB modules and sensor qualityquality

Regina DeminaUniversity of Rochester

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Of the 16 modules tested at UCSB,

Observed peculiarity in module testing :

Noise on some channels increases with bias voltage.

Micro discharge effect (also seen in D0 sensors delivered by Micron)

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Defects in channels 278 and 279. Not found in sensor probing

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Defect (scratch) in channel 333. Not found in sensor probing

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Defect in channel 377. Not found in sensor probing

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Strip 91 a known pinhole in the first sensor.

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Mid-sensor opens in channels 69-71 in the 1st sensor

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Defect in channel 166. Not found in sensor probing

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Scratch in channel 316

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Defect in channel 303. Not found in sensor probing

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Scratch in channel 344. Not found in sensor probing

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Summary Summary Summary Summary Module # Comments

875 Channel 384 has high noise, but no lithography error present. NOT SEEN IN SENSOR PROBING

874 Found High Istrip channel in 2nd sensor (294) causes noise. Remove 293-295 between sensors and module is good

873 Micro-discharge at channel 14 at 270 V (need to pluck 10-18 to remove cmn). No obvious sensor damage.

NOT SEEN IN SENSOR PROBING872 4 channels with noise increase with HV. 3 have obvious

lithographic error. NONE SEEN IN SENSOR PROBING871 Micro-discharge at channel 181 at 300 V (need to pluck 175-

187 to remove cmn). No obvious sensor damage. NOT SEEN IN SENSOR PROBING

870 Good883 Channel 166 has increasing noise with HV. Has lithographic

error (see picture). NOT SEEN IN SENSOR PROBING882 Good

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Summary Summary Summary Summary Module # Comments

881 Micro-discharge at channels 438-440 (need to pull 434-444 to stop high cmn).

Channels start discharging at 0V and get worse869 Micro-discharge at channels 29-30 (need to pull 24-36 to stop high

cmn) at 400 V868 3 mid-sensor opens, lithographic error (see photo). NOT FOUND IN

SENSOR PROBING880 NO PROBLEMS879 NO PROBLEMS878 Channel 377 has increasing noise vs bias. Lithographic error found

in second sensor (see picture). NOT SEEN IN SENSOR PROBING

877 Channel 334 has slightly higher noise at 550 V. Lithographic error found in first sensor. (See picture.) NOT FOUND IN SENSOR PROBING

876 Channels 278-279 have increasing noise vs. bias voltage. Sensor lithographic error found on both channels (see picture) NOT

FOUND IN SENSOR PROBING

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SummarySummarySummarySummary

• Out of 16 modules built 11 show some signs of micro discharge.

• Total number of noisy strips – 17

• Number of strips with high I strip – 1

• Number of strips with obvious lithographic error – 8

• Opens - 3

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