Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Silicon Detector Specification

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1 GLAST LAT PROCUREMENT SPECIFICATION Document # Document Title GLAST LAT Silicon Detector Specification Date Effective Page 1 of 21 GE A 1rst Draft 8/20/00 Author(s) Supersedes H. Sadrozinski T. Ohsugi Subsystem/Office Tracker Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Silicon Detector Specification

2 GE A GLAST LAT Silicon Detector Specification Page 2 of 21 CHANGE HISTORY LOG Revision Effective Date Description of Changes

3 GE A GLAST LAT Silicon Detector Specification Page 3 of PURPOSE These Specifications will serve as the basis for the procurement of the GLAST LAT silicon strip detectors. 2. SCOPE The specifications describe the layout, electrical and mechanical performance of the silicon strip detectors (SSD) for GLAST LAT and the tests required by the vendor. 3. DEFINITIONS 3.1 Acronyms GLAST LAT SSD TBR Gamma-ray Large Area Space Telescope Large Area Telescope Silicon Strip Detector To Be Resolved 3.2 Definitions AC Coupling The Al metal electrode is covering almost the whole length of the p+ implant, separated from it by a dielectric material AC Pad Pad to access the Al metal electrode on the strips Active Area Area of the Volume from which charge is collected on the strips in <<1us Buyer Institution procuring GLAST LAT SSD Contract Purchase agreement to procure GLAST LAT SSD s Coupling Capacitor Capacitor formed by Al metal electrode, dielectric and implant Customer Institution involved in the procurement and testing of GLAST LAT SSD s C-V Measurement of body capacitance (C) as a function of voltage (V) DC coupling Al metal electrode and implant in ohmic contact. DC Pad Pad to access the strip implant Bias Resistor Resistor connecting every implant to the bias ring Bias Ring Implant surrounding the active area, connects to bias resistors Fiducial Physical mark in the Al metal layers for alignment and metrology Guard Ring Implant ring outside the bias ring without bias connection ( floating ) I-V Measurement of leakage current (I) as a function of voltage (V) N-sub Substrate contact on the detector front Pad Area of the Al metal layer accessible through the passivation The pad area is defined as the area of the metal. Pitch Distance between strip centers Passivation Topmost layer covering of inert translucent material Seller SSD Manufacturer, Vendor Sensor Silicon Strip Detector (SSD) um Micro meter (10-6 meter) us Micro second (10-6 second) 4. REFERENCES GLAST LAT AO Response P. Michelson et al, Strip Technology T. Ohsugi et al., NIM A, 383 (1996) 167. BTEM prototype detectors Eduardo s Hiroshima Paper

4 GE A GLAST LAT Silicon Detector Specification Page 4 of REQUIREMENTS a. Wafer i. Doping n-type ii. Surface orientation: (1 0 0) iii. Wafer size: 6-inch iv. Bulk resistivity: > 4 KΩ-cm v. Thickness: , -0 um (or um) vi. Uniformity of thickness: < 5 um b. Type of the sensor i. Coupling AC ii. Biasing Polycrystalline-silicon iii. Read-out Single-sided iv. Read-out Implants p+ v. Surface covering (except for pads) Passivation glass c. Sensor Size (for a detailed layout proposal, see Sec. 5.l below) i. Outer size ( scribe line) 8.95 cm x 8.95 cm ii. Dicing Tolerance um of the scribe line vii. Uniformity of saw cut < 10 um (TBR) iii. Number of strips 384 iv. Strip pitch: 228 um v. Strip width (implant): 56 um vi. Width of strip Al electrode: 64 um vii. Active area 87,552 um x 87,552 um d. Pads ( see Figures Layout, Utility Table Pad & Fiducial Location ) i. Position of bonding & probing pads see figures ii. Bias ring double row: width 100 um x length 200 um iii. DC pad on strip at connection of bias resistor 100um x 100um iv. AC pads double row on both ends of the strip 100 um x 200 um v. N-sub contact on bias resistor side (See Figure Utility, Sec 5.l) vi. Bond strength on Pads >5grams e. Processing Details i. Mask dimension error < 0.5 um ii. Mask placement error: < 1.0 um

5 GE A GLAST LAT Silicon Detector Specification Page 5 of 21 iii. Bias ring iv. Guard ring: vii. Resistance of Al electrode on strips: implant ring DC coupled to Al electrode. similar to the bias ring < 5 Ω/cm viii. Dielectric of coupling capacitor 0.22um SiO um Si 3 N 4 (preferred solution, different choice will be subject to tests after wire bonding). ix. Coupling capacitance: >60 pf/cm x. Break down voltage of capacitor: >100V xi. Bias resistance of poly-si resistor: 50 MΩ xii. Resistance variation within a detector <+- 10MΩ xiii. Resistance variation detector by detector <+- 30 MΩ xiv. On the resistor side of the strips, the implants extend to within ~30micron of the bias ring. f. Fiducial marks (See Figures Fiducials, Utility, Table Pad & Fiducial Location ) i. fiducial marks are implemented symmetrically at each corner on the insensitive area. Position & size: Table Pad & Fiducial Location Placement accuracy: <1um. ii. 4 Alignment marks: type B close to each corner with one leg running off the edge to align with next detector iii. 4 Bonding marks: type A placed in line with bonding pads (outer pads) on both sides. iv. Eye guiding mark: (see Figure Eye Guiding Mark ) Big box with GLAST 2000 Manufacturer followed by ID #, includes Mark C. v. 4 Metrology marks: type C One inside eye guiding mark and 3 inside square box symmetrically to it vi. The sensor ID is scratched on a binary scratch pad inside the Eye guiding box. vii. The strip number is printed close to every strip outside of the guard ring on both sides (see Figure Strip Numbering Scheme ). g. Electric properties ( at 25 C, humidity <50%) i. Full depletion voltage (measured by 1/c**2): <150V ii. Leakage current per sensor at 150V, guard ring floating Maximum: < 800nA Averaged over every 100 detectors: < 240nA. iii. Onset voltage of micro-discharge: > 175V iv. Total leakage current per sensor at 175V: < 1,000nA v. Total strip capacitance (@1MHz, 150V) <1.4pF/cm vi. Interstrip isolation (@150V) >1GΩ

6 GE A GLAST LAT Silicon Detector Specification Page 6 of 21 h. Strip yield i. Bad channel rate (averaged over every 100 sensors): < 0.2% ii. Maximum number of bad channels/sensor: < 3 channels (0.8 %) (Note: Included in the dead channel count are: short circuit of coupling capacitor short circuit of strip implant or Al electrode to other strips or bias ring open circuit of readout electrode bad connection of bias resistor) i. Implementation of test detectors and structures ( see Figure Test Structures ) Several test detectors having features of the full-size detectors have to be implemented at the side of the full-size detector and supplied to GLAST LAT on a single cut-off. Positioning is shown in the figure Test Structures. i. One narrow small test detectors (~5mm x 4.4cm) having all features of the full-size detectors, but <16 strips. They are positioned next to the detector. ii. One small test ( Baby ) detector (~3cm x 3.5cm) having all features of the full-size detectors, but only 128 strips. iii. One planar diode iv. One gated diode v. A bonding test area (~3.5 cm x 4mm) with 128 pairs of bonding pads. j. Information to be supplied with each sensor by vendor i. ID # scratched in the area provided ii. The total detector leakage current vs. bias voltage (I-V) (in 5 volt steps up to 200V at 25 o C, humidity <50%). iii. A list of bad channels with their defects indicated (Coupling capacitors tested up to 100V). iv. The average value of the bias resistors and the highest and lowest value. v. The body capacitance vs. bias voltage (C-V) (in 5 volt steps up to 200V at a frequency of 1MHz). k. Radiation hardness The radiation hardness does not have to be measured on every detector, but will be verified by GLAST LAT on every 50 th (TBR) of the small test detectors. Those samples will be exposed to gamma-rays from a 60 Co radiation source up to 100 Gy in biased condition, with strips grounded to the bias ring potential. The irradiated sample detector have to satisfy the following requirements:

7 GE A GLAST LAT Silicon Detector Specification Page 7 of 21 i. Total strip capacitance (@1Mhz) <1.6pF/cm ii. Total leakage current < 20µA (@150V, 25 C, humidity <50%) If the irradiated sample detector does not satisfy the requirements, the acceptance of the detectors by GLAST LAT is immediately stopped, and only resumed after diagnosis and elimination of the problem. l. Detailed layout proposal, see Figure Layout Dimensions across the strips Distance between inside edges of Al metal bias ring: Bias ring Implant width: Al metal electrode width: Gap between bias Al and guard Al rings: Guard ring Implant width: Al metal electrode width: Distance outside guard to sensor edge: Dimensions along the strips Distance between inside edges of Al metal bias ring: Strip length (implant): Bias ring Implant width: Al metal electrode width: Gap between bias Al and guard Al rings: Guard ring Implant width: Al metal electrode width: Distance outside guard to sensor edge: 87,710 um 50 um 70 um 30 um 30 um 50 um 745 um 87,630 um 87,572 um 100 um 120 um 30 um 30 um 50 um 735 um The preferred solution for the location of the resistors is to have resistors straddling the implants, but other solutions are acceptable if meeting all performance specs (including radiation hardness, depletion and breakdown voltage and capacitance). Edge Protection The following edge protection is recommended (see Figures Layout, Utilities ) i. One floating guard ring outside the bias ring ii. Metal covering the area from the edge to within 150um of the guard ring

8 GE A GLAST LAT Silicon Detector Specification Page 8 of 21 iii. Substrate contact ( N-sub ) across the detector at the resistor end. iv. Bias ring: implant ring, covered by 1.5u thick Al with 10u overhang on each side. v. Guard ring: one guard ring similar to the bias ring is installed outside of the bias ring. vi. Implant depth: > 1um vii. Implant resistance: < 30 kω/cm viii. Aluminum electrodes Thickness: um Material: pure Al

9 GE A GLAST LAT Silicon Detector Specification Page 9 of 21 GLAST2000 Pad & Fiducials Location : (Ctr of Pad or Mark on left side only, all in micron)) X is normal to strips, y along strips (0,0) is in the center of the detector Resistor end is at negative y. Non-Resistor End Resistor End Size (x*y) x y x y Pads First Bond 100x First Probe 100x DC 100x100 n.a. n.a Bias 1 100x Bias 2 100x Fiducials Bond A Probe A Alignment B Metrology C Eye guiding mark 400(TBR) x Detector edge x = or y = Substrate contact : x 200 with center at (0, ) Metal cover plate within 150micron outside of outer edge guard ring Bias ring contact along the entire detector width at the resistor side.

10 GE A GLAST LAT Silicon Detector Specification Page 10 of 21 GLAST 2000 Fiducial Alignment Type B µ center µ 2000/7/06 T. Ohsugi 2000/8/2 HFWS 300 µ G L A S T m a k e r ' s n a m e Bondin Mark Type A µ ID pads Metrolog Mark Type C Probin Mark Type A µ center µ µ from center µ 400 µ Type A Mark Type B Mark 500um Type C Mark 500um Remark: The length of cross hair line is 100µ and line width is 15µ, if it is not specified.

11 GE A GLAST LAT Silicon Detector Specification Page 11 of /8/01 GLAST 2000 utilities layout revised T. Ohsugi strip numbering area cent er 44,750 µ edge metal cover subst rat e probing area N-sub 44,325 µ bias resist or implement ed side Bias Ring Probe access Across entire Detectors center 9,900 30,000 Eye guide mark & scrat ch pads for ID 250 GLAST 2000 [maker's name] fiducial mark type C scrat ch pads T digit s BCD

12 GE A GLAST LAT Silicon Detector Specification Page 12 of 21 Eye Guide Mark & ID Number 2000/8/1 T. Ohsugi 9,900 GLAST 2000 Vender's Name BCD ID No. 2, , BCD ID Number Format S R Q P O ID x

GE-00011-A GLAST LAT Silicon Detector Specification

13 GE A GLAST LAT Silicon Detector Specification Page 13 of 21 GLAST2000 Proposed Layout 745um 730um 745um

14 . GE A GLAST LAT Silicon Detector Specification Page 14 of 21 GLAST2000 Proposed Layout (continued) Guard (implant 30µ, Al cover ring gap 30 µ GLAST Silicon Detector 2000 Bias (implant 50µ, Al cover 70µ) i to Fig. A B Implanted strip (width=56µ) side µ from the center Al ( l d width=6 4 µ ) strip = 228 µ bonding 100µ d x 200µ 300 µ 730 µ 100 x µ 745 µ 635µ 825 µ 650µ 150µ 735µ from the scribed f 4 d 5 29µ 120 µ 50 µ DC probing pad 100µ x 100µ 30 µ probing d

15 GE A GLAST LAT Silicon Detector Specification Page 15 of 21 Test structures for GLAST ) Full Length Test structure: Narrow test detector. having the same length as GLAST2000, <16 strips wide. It is an exact replica of the GLAST2000 detector (It has 4 rows of bond pads on the Al strips, 50Mohm resistors, dead area etc) With the exception of the Number of strips (<16 instead of 384). 2) Diode 0.5 cm x 0.5 cm 3) Gated Diode 0.5 cm x 0.5 cm 4) Baby detector 3cm x 3.5cm, 128 strips HFWS 7/30/00 5) Bonding Test Structure: 128 pad pairs 3.5cm x 4mm Dice Line GLAST Cut-off

16 GE A GLAST LAT Silicon Detector Specification Page 16 of 21 Test Structures (continued) GLAST2000 Cut-off Full-Length Test structure <5mm x 8.95cm Photo Diode Small Detector 3cmx3.5cm 128 channels Bonding Test Pad 128 pairs ~3.5mm apart 3.5cm x 4mm Gated Photo Diode

17 GE A GLAST LAT Silicon Detector Specification Page 17 of 21 Test Structures (continued) Bonding Test Pads 128 pad pairs (about 3.5cm long, 4 mm wide) Including Probing and Bonding Pads and Bonding Fiducials (Mark A) (not to scale) 128 * 228 3cm

18 GE A GLAST LAT Silicon Detector Specification Page 18 of 21 Strip Numbering Scheme (Both sides)

19 GE A GLAST LAT Silicon Detector Specification Page 19 of QUALITY ASSURANCE PROVISIONS QUALITY ASSURANCE DOCUMENTATION DELIVERY Unless otherwise specified, seller shall submit all documents required by this contract to be delivered to the Buyer. A document is not delivered until it is received by Buyer. Buyer shall have the right to reject, as not in conformity with the requirements of this contract, any supplies or services for which all required reports, procedures or certifications are to delivered. Seller s failure to deliver such documents, or delivery of deficient documents shall be deemed a failure to make delivery within the meaning of the Default clause of this contract QUALITY PROGRAM/SYSTEM REQUIREMENT The Seller shall provide and maintain a quality program/system that compiles with any recognized U.S. Quality Program/System Standard in Effect on the contract date (e.g., ISO 9001, MIL-I-45208, ANSI N45.2) or equivalent. The Seller shall require, in writing, subcontractors of all tiers to comply with all applicable quality program/system requirements. The quality system and control of Special Processes of the Seller and Subcontractors of all tiers shall be subject to audit by the extent practicable at all times an places. The Seller shall tender for acceptance only those supplies or services that have been inspected and tested in accordance with its quality program/system and have been found to conform with contract requirements. SUBMITTAL(S) REQUIRED AFTER CONTRACT DATE Prior to the performance of any operations involving the following, but in no event later than 30 calendar days after the contract date, the Seller shall deliver for Buyer s review and approval: (1) a concise explanation of all manufacturing processes and assembly procedure/plans, (2) a production and delivery schedule, (3) an Inspection and Test Plan. The plan shall specify, as a minimum: (1) what is to be inspected/tested (e.g., components, subassemblies, and assemblies), (2) the inspections/tests to be performed, and (3) the inspection/test methods or procedures to be used. (4) all proposed changes to the Customer s design or specifications. (5) evidence of its quality program/system. Such evidence may consist of a copy of the Offeror s approved QA/QC plan, or a combination thereof, and shall specify the standard(s) upon which the system is based.

20 GE A GLAST LAT Silicon Detector Specification Page 20 of 21 Buyer will notify the Seller of its approval or disapproval within 30 calendar days; provided, however, that if notice is not issued within such time, the Seller s procedure shall be deemed approved. For the purposes of this clause, an approval or disapproval notice is issued when it is sent. PRE-AWARD SURVEY OF PROSPECTIVE SUPPLIER When deemed necessary by the Buyer, a pre-award survey will be conducted of a sellers technical, quality assurance, production, or financial capability. Evaluation of documented quality assurance program/system applicable to SSD s to be produced by the seller may include but shall not be limited to inspection and test controls, calibration of measuring and test equipment, special process controls, materials storage and handling, and drawing change controls. Specifically, the seller has to furnished evidence that he can produce and test on schedule SSD s on 6 wafers to the GLAST LAT specifications. At the time of the bid submission, detector samples have to be furnished which clearly show that the process is sufficiently advanced that the technical specification (including radiation hardness) can be met. GLAST will subject these samples to tests of the detector specifications outlined in the requirements, including measurements after irradiation and wire bonding. FIRST ARTICLE TEST The Seller shall deliver 25 first article to the customer for first article tests. Before first article approval, the acquisition of materials or components for, or the commencement of production of, the balance of the contract quantity is at the sole risk of Seller. FINAL ACCEPTANCE Notwithstanding the inspection requirements at the Seller s facilities, final acceptance of all silicon strip detectors shall take place following delivery to and testing by the Buyer. The buyer reserves the right to perform any or all test which would be required to verify that the silicon strip detectors conform to the requirements of the specifications supplied to the Supplier as part of this contract. Silicon strip detectors which fail any of the tests performed will be deemed unacceptable and returned to the Seller for replacement at no cost to the Buyer. Shipping cost of return and replacement shall also be borne by the Seller. SELLER INSPECTION REQUIREMENTS The Seller shall perform or have performed all inspections and tests necessary to substantiate that the silicon strip detectors tendered for acceptance conform to contract requirements. Such inspections and tests shall include, but not be limited to the tests specified in the Technical Specification, and shall include: Dimensions of cut SSD (length, width, alignment to mask, thickness, quality of edge cut ) Mask dimensions and alignment I-V, C-V, Bias resistor values Capacitor breakdown up to 100V, Shorted and open metal electrodes and implants, disconnected bias resistors Visual inspection

21 GE A GLAST LAT Silicon Detector Specification Page 21 of 21 SELLER REPORTS(S) Seller shall submit for silicon strip detectors, Functional Test Report(s) of the actual test results, specifying what was tested, the requirements/parameters tested, and the acceptance criteria, all as required by the Technical Specification. The submittal shall be made both in electronic form (Excell format) and in paper form. HANDLING, SHIPMENT AND DELIVERY The Seller shall package and ship the silicon strip detectors by a method that ensures that the silicon strip detectors are delivered to the Buyer free from any damage. Every shipment has to contain the corresponding GLAST cut-off s containing the test structures, identified by the shipped SSD s ID#. SOURCE INSPECTION The Buyer shall be permitted access to witness any phase of manufacturing, testing and conditioning of the silicon strip detectors. Upon request, the Seller shall make available to the Buyer all reports and data on materials and procurement, on tests, and manufacturing, or other operations which pertain to the silicon strip detectors. After a request for inspection, the Seller shall notify the Buyer no less than 7 working days in advance of any function or operation chosen to be witnessed or inspected by the Buyer s representative. NONCONFORMANCE AND CORRECTIVE ACTION Any departure from the requirements of the specification and drawings which the Seller proposes to make shall be documented and submitted to the Buyer for approval.

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