1. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam Gossopo3 3 rd Prototype of a front-end chip for 3D MPGD 1/27/20091GOSSIPPO3 prototype

2. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam The GOSSIP Detector principle Gas On Slimmed Silicon Pixels A low mass, radiation hard, detector for High rate, experiments Drift time measurement enables track reconstruction. Gas filled drift volume Silicon substrate (front end chip),ground; 0 V Cathode plane -500V GRID plane -400V 1/27/20092GOSSIPPO3 prototype

3. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam Requirements for Front-End Good efficiency for 1000e - input signals : Noise <100e - rms. Fast input for accurate drift time determination: ~1-2ns resolution => peaking time ~30ns. Low power for high resolution: Goal 100mW/cm 2, with 55 µm pixels => 3 µW/pixel Need Preamp, Discriminator, TDC (4b), ToT (4b), Buffers, Configuration (e.g. Threshold DAC) and test for each pixel. For SLHC design (future): Bunch & Event identification More (2?) event buffers per pixel Serial communication & Trigger handling High speed serial readout (>Gb/s), ATLAS compatible. 1/27/20093GOSSIPPO3 prototype

4. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam Prototyping history …2006: GOSSIPO-1 analogue front-end low input capacitance (30 fF) preamp with 1fF feedback. MEDIPIX with INGRID Works OK, but need better spark protection SiProt & later NiProd show good results 2007 TIMEPIX with INGRID and thicker SiProt spark protection much better, all tests not ready PSI46 with INGRID in progress, demonstrate gas detector. GOSSIPO-2 (2007) 16x16 prototype array, chip ok, need improvement Post process difficult (small) 1/27/20094GOSSIPPO3 prototype

5. R. Kluit Nikhef Amsterdam GOSSIP Front-End prototype Goal: Design a chip that can be used to build a functional detector. Prove GOSSIP concept with electronics designed specifically for this detector. Simple readout & compatible with ext. Trig. Now need larger and improved design. 1/27/2009GOSSIPPO3 prototype5 clk & signal drivers/colµmn clk &signal drivers 16x16 pixel cell array test 2006 GOSSIPO-2 chip: 256 55 x 55 µm pixels total area: 0.88 x 0.88 mm

6. R. Kluit Nikhef Amsterdam Pixel cell (2006) Only “Slow” clock distribution, 40 MHz “Fast” clock from local oscillator per pixel, 560MHz 4 bit TDC & latency counter > 1.78 ns resolution & 350 ns range. 4 bit DAC for threshold tuning control register for masking, test-pulse enable and DAC 1/27/2009GOSSIPPO3 prototype6 A preamp discriminator 4 bit DAC 4 bit LFSR fast osc. threshold adjust input pad enable test mask hit 6 bit conf. reg. test pulse bias lines threshold conf. data conf. clock event clockdata enable self clear reset enable clear TDC control

7. R. Kluit Nikhef Amsterdam GOSSIPO3 Motivation for GOSSIPO3: Verification of: Time resolution: drift time (1.6ns) & ToT (25ns) Noise : <80e- rms Power: <3µW/pixel Pixel uniformity: -Threshold spread (< noise σ ) -Gain, Time meas., etc. Discharge (spark) protection Demonstrate a detector of ~2x2 mm in Beam test 2010. 1/27/2009GOSSIPPO3 prototype7 Active pixel with INGRID Active pixel with INGRID

8. R. Kluit Nikhef Amsterdam New chip proposal 1/27/2009GOSSIPPO3 prototype8

9. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam Gossipo2: 2.0 x 3.0 => 3.0 x 3.5 mm 2 => size 10.5 mm 2 (~$48 k in MOSIS) Pixel size : gossipo2: 55 x 55 => 55 x 55 μ m cell size Sens. Area:gossipo2: 0.88 x 0.88 => 1.76 x 1.76 mm gossipo2: 16 x 16 => 32 x 32 aktive Pixels Need ~540 μ m space between matrix and edge chip Dyke Need 4 rows of terminating (dummy) pixels, total array 40x40 pixels Chip size ~ 3.3 x 3.7 mm Need some (3) analogue pixel outputs on edge matrix Study the ion drift and pulse shape (add analog output buffers) Area available outside pixel array for other test structures: Preamp, Discriminator, TDC, Bias, ….. (will be buried under InGrid dyke) Chip size & pixels 1/27/2009GOSSIPPO3 prototype9 20-1-2009 @Bonn

10. R. Kluit Nikhef Amsterdam Gossipo3 (1) 1/27/2009GOSSIPPO3 prototype10 In each pixel: -Preamp & Discriminator -Threshold DAC + reg. -TDC 4bit, 1.7 ns bins -ToT 4bit, 25ns bins -Read Latency counter, 4bit (400ns) or 2-100us (12b)? -Configuration reg. Readout data: 4 + 4 + (4 to12?)= 12 to 20 bits/pixel Self trigger/Fast OR Yes Test modes (Yes) Timed readout, variable latency Readout all pixels Buffer/pixel, auto clear after latency Readout speed 40MHz ? 20-1-2009 @Bonn

11. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam No design for Radiation tolerance (yet, but keep in mind). Low power design => Goal 100mW/cm 2, => 3uW/pixel @ 55x55um pixels Simple readout, shift all out @40MHz Simple Chip Configuration, shift in. Choose IBM 130nm Technology options, LM/DM,.. Share work on Preamp (FE-I4 like), discriminator, TDC, Threshold DAC, Bias, test circuits, GridTrig Preamp (?), Fast-OR,…. Proposal: Main engineer: V. Gromov. Blocks by Nikhef & Bonn. Discuss in weekly meeting, Tuesdays 15:00. Can we use design repository as with FE-I4 design group ? Gossipo3 (2) 20-1-2009 @Bonn 1/27/200911GOSSIPPO3 prototype

12. R. Kluit Nikhef Amsterdam Next Slides: Vladimir Analog, Sinan digital. Discussion -additional features and requirements. -Participation Time scale: 2009: -Spec & feasibility …May -design …Sept -tape-out Nov. 2010: -Chip test March- May -Detector processing …. -Beam test Aug-Oct? 1/27/2009GOSSIPPO3 prototype12 20-1-2009 @Bonn

13. R. Kluit Nikhef Amsterdam Additional prototype Proposal: Before Gossipo3 submission (~12mm 2 ), test basic circuits: Preamp (with bias) Discriminator (with bias) TDC/oscillator ? other features ? (MOSIS MPW May 11 th, July 20 th ?) (Name Gossipo3.0 &..3.1, or proto =..3, and next is..4) 1/27/2009GOSSIPPO3 prototype13

14. R. Kluit Nikhef Amsterdam Work partitioning (preliminary) 1/27/2009GOSSIPPO3 prototype14 PartStatusWorkdesignlayoutDesigners PreampConcept designDesign, simulation, implementation-- DiscriminatorConcept design-- Threshold DAC/opampIdea/prop.? TDC & countersConcept designNikhef Fast-ORplan “” ReadoutLike gossipo2Nikhef Bias blocks--? I/O pads & buffersSome of gossipo2? Signal distribution/buffers --Nikhef(?) Power distribution analysis (TDC) plan-- INGRID preamp ?--New item: specify & design? Chip integration--Full chip assembly & verificationNikhef

15. R. Kluit Nikhef Amsterdam R. Kluit Nikhef Amsterdam Mean Input signal charge (distribution) required threshold spread, gain, Test pulse feature INGRID preamp, feasibility, specs ? … Open issues on requirements 1/27/2009GOSSIPPO3 prototype15

16. R. Kluit Nikhef Amsterdam additional slides …. 1/27/2009GOSSIPPO3 prototype16

17. R. Kluit Nikhef Amsterdam preamp DAC R oscillator & discr. Control reg Latency counter logic TDC LFSR Pixel cell (2006) 1/27/2009GOSSIPPO3 prototype17 8 metal layers 55 x 55 µm

18. R. Kluit Nikhef Amsterdam GOSSIPO-2 chip layout 1/27/2009GOSSIPPO3 prototype18

19. R. Kluit Nikhef Amsterdam Layer stack at the input 1/27/2009GOSSIPPO3 prototype19 oxide V M7 VL M6 M5 V6 0.2 µm M6 M5 V6 0.72 µm 0.2 µm M6 M5 V6 0.2 µm V VL M6 M5 V6 M6 M5 V6 0.72 µm 0.2 µm M6 M5 V6 0.2 µm M6 M7 0.2 µm 2 µm 0.2 µm 5 µm High Resistive Amorphous Silicon opening 14 x 14 µm Metal layer (Al) 20 x 20 µm Nitride Nitride + oxide Nitride Nitride + oxide Integrated grid ( ≈ 1 µm thick metal grid) 50 µm Polyimide pillars M8, 21 µm x 21 µm opening 14 x 14 µm 10 x 10 µm M8, 21 µm x 21 µm preamp inputpreamp output preamp feedback 1.9 fF test input capacitance 13.5 fF Metal layer (Al) 20 x 20 µm wafer post processing chip wafer 55 µm pitch Nitride dimensions not to scale

20. R. Kluit Nikhef Amsterdam Spark protection 1/27/2009GOSSIPPO3 prototype20 -400 V from INGRID to electronics discharge gives ± 2 nC, burns a hole ! Add shield (GND) over signal routing on top of the chip (top layer) With NiProt, only area of pixel pad size makes Capacitance to input circuit : Q breakthrough = ± 8 pC Negative discharge: need “Diode” to substrate For example GOSSPO-2 preamp: NMOS in preamp DC feedback has diode (drain) to substrate (ground). Process requires “tie-down” diode to input. Area of diodes is large enough for protection of positive discharges. But, need negative. Total input capacitance ~30 fF. C NiProt -400V GOSSIPO2 preamp

21. R. Kluit Nikhef Amsterdam transistor current preamp input voltage present gossipo2 preamp with GGNFET and without Spark Protection Device 1/27/2009GOSSIPPO3 prototype21 Grounded gate NFET : W/L= 6/0.12 µm Dissipation in channel and drain diode area. 8pC in this volume > Δ T = 1° lpnfet C par ≈ 3-5 fF. Use Low Power NFET: no leakage current (<1 pA) at DC operating point of preamp input ( 0.4 V) pad preamp During negative breakthrough : Vin should not exceed -1.5 V. This determines the size of protection device.