Radiation-Hard Optical Link in the ATLAS Pixel Detector

Transcription

1 Radiation-Hard Optica Link in the ATLAS Pixe Detector K.K. Gan The Ohio State University August 18, 2004 K.E. Arms, K.K. Gan, M. Johnson, H. Kagan, R. Kass, A. Rahimi, C. Rush, S. Smith, R. Ter-Antonian, M.M. Zoeer The Ohio State University A. Ciiox, M. Hoder, S. Nderitu, M. Ziokowski Universitaet Siegen, Germany K.K. Gan ICHEP04 1

2 Outine Introduction Resuts on IBM 0.25 mm Chips Resuts on Proton Irradiations Summary K.K. Gan ICHEP04 2

3 ATLAS Pixe Detector Inner most tracking detector Pixe size: 50 mm x 400 mm 100 miion channes Barre ayers at r = 5.1, 12.3 cm Disks at z = 50, 65 cm Dosage after 10 years: u optica ink: 30 Mrad or 6 x MeV n eq /cm 2 K.K. Gan ICHEP04 3

4 ATLAS Pixe Opto-ink VCSEL: Vertica Cavity Surface Emitting Laser diode VDC: PIN: DORIC: VCSEL Driver Circuit PiN diode Digita Optica Receiver Integrated Circuit K.K. Gan ICHEP04 4

5 VDC: VCSEL Driver Circuit Convert LVDS input signa into singe-ended signa appropriate to drive VCSEL diode Output (bright) current: 0 to 20 ma u controed by externa current I set Standing (dim) current: ~ 1 ma u improve switching speed Rise & fa times: 1 ns nomina for 40 MHz signas On votage of VCSEL: up to 2.3 V at 20 ma for 2.5 V suppy Constant current consumption! Use Trueight high-power oxide common cathode VCSEL array K.K. Gan ICHEP04 5

6 DORIC: Digita Optica Receiver IC Decode Bi-Phase Mark encoded (BPM) cock and command signas from PIN diode Input signa: ma Extract: 40 MHz cock Duty cyce: (50 ± 4)% Tota timing error: < 1 ns Bit Error Rate (BER): < at end of ife Use Trueight common cathode PIN array 40 MHz cock command BPM K.K. Gan ICHEP04 6

7 Origina design for ATLAS SemiConductor Tracker (SCT) q AMS 0.8 mm BiPoar in radiation toerant process (4 V) DMILL #1-3: Summer May 2001 q 0.8 mm CMOS rad-hard process (3.2 V) q VDC & DORIC #3: meet specs q severe degradation of circuit performance in Apri 2001 proton irradiation IBM #1-5: Summer Dec 2002 q 0.25 mm CMOS rad-hard process (2.5 V) q Status of VDC & DORIC encosed ayout transistors and guard rings for improved radiation hardness IBM 5e: Apri 2003 engineering run q convert 3-ayer to 5-ayer ayout for submission with pixe Modue Contro Chip (MCC) for cost saving a this is the production run since chips meet specs and sufficient quantity of chips were produced K.K. Gan ICHEP04 7

8 VDC-I5e: Bright and Dim Currents vs. I set 15 High-power oxide VCSEL bright 10 I (ma) 5 8 chips measured 4 channes/chip I set (ma) dim dim current is ~ 1 ma as expected bright current measured with 1 W in series maximum bright current is ~ 13 ma u oxide VCSEL has arger effective resistance than p + impanted VCSEL u target is 20 ma but 13 ma is adequate for anneaing from irradiation damage K.K. Gan ICHEP04 8

9 DORIC: PIN Current Threshods with No Bit Errors Current (ma) Link threshods significanty better than spec: 40 ma K.K. Gan ICHEP04 9

10 Status of BeO Opto-board converts: optica signa eectrica signa contains 7 optica inks use BeO for heat management but prototype initiay in FR-4 for fast turnaround and cost saving 1st BeO prototype: u many open vias due to insufficient god fiing 4 opto-inks works after via repairs! 2nd BeO prototype: u recyced BeO boards u many shorts due to over fiing a use more experienced/expensive vendor a produced opto-boards of high quaity K.K. Gan ICHEP04 10

11 BeO Opto-board housing opto-pack DORIC VDC K.K. Gan ICHEP04 11

12 2000 Optica Power Power (mw) Channe optica power at 10 ma significanty above spec: 500 mw K.K. Gan ICHEP04 12

13 28 boards were deivered Opto-board Status u ~equa mixture of boards for ayers B and 1, 2, disk u popuated opto-boards have ow noise and good optica power a no known circuit design errors u a few SMD detached from three boards a produce 80 B-ayer boards with ayout changes to improve adhesion a expected deivery in September n if new boards are satisfactory a produce 430 boards for ayers 1, 2, and disk K.K. Gan ICHEP04 13

14 Threshod ( m A) PIN Current Threshod vs Dosage Dosage (Mrad) annea annea annea annea annea L1 L2 L3 L4 L5 L6 L Time (h) PIN current threshods for no bit errors remain constant K.K. Gan ICHEP04 14

15 Proton Induced Bit Errors in PIN convert observed bit errors into bit error rate at opto-ink ocation: 1.E BER 1.E-09 1.E-10 1.E-11 Link: E-12 I PIN (ma) bit error rate decreases with increasing PIN current as expected bit error rate ~ 3 x at 100 ma (1.4 errors/minute) n DORIC spec: K.K. Gan ICHEP04 15

16 Optica Power vs Dosage irradiation procedure: ~ 5 Mrad/day (10 hours) with the rest of day anneaing optica power decreases with dosage as expected imited anneaing recovers some ost power sti have good optica power after 30 Mrad K.K. Gan ICHEP04 16

17 Summary VDC-I5e & DORIC-I5e (IBM 0.25 mm): 4 radiation hard up to 62 Mrad 4 meet ATLAS pixe specs 4 production is competed BeO opto-board: 4 severa pre-production opto-boards have been fabricated q ow PIN current threshods for no bit errors q exceent optica power 4 radiation hard up to ~ 30 Mrad n modify ayout to improve SMD adhesion start opto-ink production in September 2004 n compete production by September 2005 K.K. Gan ICHEP04 17