Electrical characterization results for wafers from different vendors Maria Rita Coluccia December 10, 2001
OUTLINE 6 CiS wafers (ATLAS p-spray sensors production) 2 IRST (Trento) wafers (ATLAS p-spray sensors prototype II) several SINTEF wafers (p-stop sensors) I-V curves for several wafers from 3 vendors:
CiS WAFER LAYOUT ATLAS PIXEL SENSORS PRE-PRODUCTION sc 4 sc 5 sc 6sc 7 sc 8 sc 9 ti 1 ti 2 ti 3
CiS single chip sensors (1) moderated p-spray sensors
CiS single chip sensors (2) moderated p-spray sensors
CiS single chip sensors (3) moderate p-spray sensors
CiS tile sensors moderate p-spray sensors
Comparison between our and ATLAS measurements
IRST WAFER LAYOUT ATLAS PIXEL SENSORS PROTOTYPE II SMD small dot grid (baseline) LAD large dot grid NOD no dot grid ST single chip, tile-like SE single chip, equal size pixel SB single chip, bricked
IRST single chip sensors (1) moderated p-spray sensors
IRST tile sensors moderated p-spray sensors
SINTEF single chip sensors (p-stop sensors) (1)
SINTEF single chip sensors (2)
SINTEF single chip sensors (3)
SINTEF five chip modules (1)
SINTEF five chip module (2)
Summary ATLAS P-SPRAY PIXEL SENSORS: CiS wafers : 1. good performance for single chip sensors ( 32 of the 36 sensors show no breakdown voltage below 500V and I~ 60 nA after depletion) (V dep ~ 50V) 2. all the tile sensors show bad performances IRST wafers : 1. few single chip sensors show breakdown voltage around 200V (V dep ~ 40V) all the others are no good 2. Also in this case the tile sensors show bad performance ATLAS collaboration explains the tile sensors bad performance as due to a bad impurities control process during the wafer production. SINTEF P-STOP PIXEL SENSORS: 1. single chip sensors show a breakdown voltage ~ 300 V (V dep ~200V, I~10nA), few show bad performance 2. five chip modules show the same single chip sensors performance