GLAST Large Area Telescope: Tracker Subsystem WBS 4.1.4 5C: Silicon Detector Procurement

1. Gamma-ray Large Area Space Telescope GLAST Large Area Telescope: Tracker Subsystem WBS 4.1.4 5C: Silicon Detector Procurement Hartmut F.-W. Sadrozinski Santa Cruz Institute for Particle Physics University of California at Santa Cruz Tracker Subsystem Scientist hartmut@scipp.ucsc.edu

2. LAT TKR Silicon Detector Procurement • Applicable LAT documents: • Specifications • LAT-DS-00011LAT SSD Technical Specifications • LAT-DS-00026LAT Flight SSD Drawings • LAT-DS-00027LAT Test Structure Drawings • LAT-CR-00082 LAT SSD Quality and Reliability Assurance • LAT-TD-00085 Testing Procedures for the GLAST LAT SSDs • Test Results • LAT-TD-00086 LAT Review of SSD RHA Test Results • LAT-TD-00128 Results from Heavy Ion Irradiation (SSD) • LAT-QR-01078 Q/A OF THE GLAST LAT SSD: RHA

3. GLAST Cut-off “Skinny” TKR Silicon Strip Detectors (SSD) • GLAST has driven the 6” wafer technology • Area: 8.95 cm x 8.95 cm • Thickness: 400 um, pitch 228 um • Very aggressive specs • (leakage currents, bad strips, dicing) • Complete testing by HPK GLAST Cut-of “Skinny” • Q/A • Every wafer has flight SSD and test structures (coupons, “cut-offs”) • Cut-off has full length, 8 channel SSD • (“Skinny”) and assorted other detectors • Flight SSD and “Skinny” are marked with same ID# • Cut-offs are used for RHA, long-term testing, glueing, wire bonding, etc. GLAST Flight SSD

4. TKR SSD RHA at Hiroshima University • RHA and Production Q/A for one SSD from each shipping lot • The LAT SSD Q/A provisions LAT-CR-00082 define the irradiations to be performed as part of the procurement process. One irradiation with 60Co per shipping lot has to be performed on coupons made on the same wafers as the flight SSDs, and several critical electrical parameters measured pre- and post-rad. • It turns out that the radiation monitoring has been carried out on 77 production runs and no problem has been found. • Procedures • The monitor sensors were irradiated up to a TID of 10 krad(Si), with a dose rate of 3.8 rad(Si)/s. • Of the 77 test sensors, 21 were biased during irradiation at 150 V. After the irradiation, these monitor sensors were kept under 150 V bias at 20 oC until they were electrically characterized for one week after irradiation. The rest of 56 sensors were not biased during irradiation and the one week annealing period. • Electrical tests performed: leakage current, interstrip capacitance and interstrip isolation

5. TKR SSD Procurement • # of SSD for 16 (+2 spare) towers: • 4 SSD/ladder*2*4Ladders/tray*18trays/tower*18towers = 10,368 • + spares • + wastage • + prototypes • Total Purchase: 11,535 • Funding: • INFN/ASI 5,000 • Japan 6,535 • Prototyping from 1996-2000, use 550 SSD in BTEM/BFEM

6. TKR SSD Delivery Profile

7. ASI & Japan Japan INFN TKR SSD Production & Funding Plan Sep 2003 “Tested” = Final Production step at HPK

8. TKR SSD Production Reality | 2001 | 2002 |2003

9. TKR SSD Procurement: Conclusions • Quality: • Outstanding • Production: • ~500 - 700 per month • Delivery: • 2 weeks after purchase possible • Testing: • Flight at HPK and INFN Pisa • Irradiated test structures at Hiroshima U. • “Cut-offs” for testing of assembly steps • Concern: • Funding by ASI in Summer 2003