1) CMOS-Sensors for vertex-detectors 2) CMOS-Sensors for X-ray imaging 3) Sensor with a 3-T-preamplifier 4) Sensor with nearly full depletion

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David Cuthbert Holmes
5 years ago
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1 AD vanced MO nolithic ensors for S CMOS-sensors for energy-resolved X-ray imaging Dennis Doering, Samir Amar, Jerome Baudot², Michael Deveaux, Wojciech Dulinski², Maciej Kachel², Tomasz Hemperek³, Christian Müntz, Sarah Ottersbach, Joachim Stroth ) Institut für Kernphysik Frankfurt ) IPHC Strasbourg 3) Universität Bonn ) CMOS-Sensors for vertex-detectors ) CMOS-Sensors for X-ray imaging 3) Sensor with a 3-T-preamplifier 4) Sensor with nearly full depletion Supported by BMBF (6FY999I and 6FY73I), HIC for FAIR, GSI and EU-FP7

2 CMOS-sensors for vertex detectors MAPS are developed for applications as vertex detector since 999 at IPHC (Strasbourg). Picture STAR ITS-Upgrade ALICE STAR-Experiment Picture CBM International Linear Collider CBM-Experiment (FAIR, GSI) Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 /7 /5

3 Direct topological reconstruction of Charm Displaced verticies Required vertex detector: - Spatial resolution - Granularity - Material budget - Radiation hardness - Read-out-speed Optimized CMOS Monolithic Active Pixel sensors Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 3 /7 /5

CMOS-Sensors for X-ray imaging Advantages - Low noise - Spatial resolution - Production in industrial processes - No bump bonding Established for Black&White X-ray imaging www.suni.

4 CMOS-Sensors for X-ray imaging Advantages - Low noise - Spatial resolution - Production in industrial processes - No bump bonding Established for Black&White X-ray imaging - Is there a possibility to extract an energy information to perform colored X-ray-imaging? Single photon counting Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 4 /7 /5

5 The sensor: MIMOSA-9 (8) Produced in an AMS-.35µm process - Low-resis:vity (Ωcm) 5µm thin EPI - Low deple:on voltage - 3T-preamplifier - 9*9 pixels Operated in single photon coun:ng mode MIMOSA-9- Electron diffusion L-Diode.5 µm 9.5µm 9.5µm Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 5 /7 /5

6 Operation principle of CMOS-sensors SiO SiO SiO P-Well N+ Diode N+ P+ Epitaxial Layer e- e- P- Depleted zone Substrate P+ Particle Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 6 /7 /5

7 Operation principle of the 3T-preamplifier Reset transistor +3.3V K I Reset U K 3 C The reset transistor closes to refill the potential U K at the capacity Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 7 /7 /5

8 Operation principle of the 3T-preamplifier Reset transistor +3.3V K U K 3 U F I Leakage C U F CDS=U F - U F Leakage current slightly lowers the potential, measured twice & compared (CDS) Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 8 /7 /5

9 Operation principle of the 3T-preamplifier Reset transistor +3.3V K I Reset U K 3 U F C U F CDS=U F - U F After that, the reset transistor closes to refill the potential Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 9 /7 /5

10 Operation principle of the 3T-preamplifier Reset transistor +3.3V K U K 3 U F U F I Leakage I Signal C U F U F particle CDS=U F - U F A crossing particle generates signal charge in the diode, lowering the potential and increasing CDS Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 /7 /5

11 Operation principle of the 3T-preamplifier Reset transistor +3.3V K I Reset U K 3 U F U F U F I Leakage C U F U F U F CDS=U F - U F The next frame does not contain signal charge, only leakage current Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 /7 /5

12 Operation principle of the 3T-preamplifier Reset transistor +3.3V K I Reset U K 3 U F U F U F I Leakage C U F U F U F Signal amplitude Leakage current Average and substract the leakage current to extract the signal amplitude Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 /7 /5

Charge smearing between pixels One pixel: Fluorescence spectrum of the setup One "seed" pixel P-Well Epitaxial Layer e- e- Diode Photon P- Depleted zone P+ Counts [/36e] 8 6 4 Pixel charge smearing +

13 Charge smearing between pixels One pixel: Fluorescence spectrum of the setup One "seed" pixel P-Well Epitaxial Layer e- e- Diode Photon P- Depleted zone P+ Counts [/36e] Pixel charge smearing + C Cd-9-source (support is built up of brass) Ag K α,k β Ag Kα (cal) Ag Kβ Collected electrons [ke] Chip (PCB contains Ba) Drawback: Charge smearing Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 3 /7 /5

14 Cluster of 5 pixels Cluster of 5 pixels Fluorescence spectrum of the setup P-Well Epitaxial Layer e- e- Diode Photon P- Depleted zone P+ Counts [/36e] Ba Lα Cu Kα One "seed" pixel Cluster + C Ag Kα (cal) Cd-9-source (support is built up of brass) Ag K α,k β Ag Kβ Collected electrons [ke] Chip (PCB contains Ba) Disadvantage: Noise contribution of 5 pixels Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 4 /7 /5

15 Trigger on conversions in the depleted zone Fluorescence spectrum of the setup P-Well Epitaxial Layer Cd-9-source (support is built up of brass) Diode e- e- P- Depleted zone P+ Photon Ag K α,k β Counts [/36e] Ba Lα Ag Kα (cal) Cu Kα V Kα Zn Kα Depleted zone Ag Kβ Collected electrons [ke] + C Chip (PCB contains Ba) Triggercondition: Neighboring pixel carry no charge Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 5 /7 /5

16 Trigger on conversions in the depleted zone P-Well Epitaxial Layer Cd-9-source (support is built up of brass) Diode e- e- Ag K α,k β P- Depleted zone P+ Photon Counts [/36e] Ba Lα Fluorescence spectrum of the setup Depleted zone Cluster V Kα Cu Kα Zn Kα Ag Kα (cal) Ag Kβ Collected electrons [ke] + C Chip (PCB contains Ba) Drawback: Reduced quantum efficiency Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 6 /7 /5

17 Linearity of amplification chain 5 + C Ag Kβ Energy of the identified peak [kev] 5 5 Ag Kα Cu Kα Zn Kα Mn Kβ Ba Lα Mn Kα V Kα Energy[keV]=(.364±.4) Q coll [ADC]+(-.4±.5) Charge collected [ADC] Linear energy scale at least between a few kev up to kev Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 7 /7 /5

18 Comparison with a Ge-detector (Cu-Kα-Line) Li-drifted Ge-detector T=+ C T Liquid N =-96 C Comparable energy resolution + Operation at room temperature possible + Spatial information available - Reduced quantum efficiency due to single photon counting Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 8 /7 /5

19 Strategies to increase the depleted volume High-resistivity: Decrease of doping concentration in epitaxial layer. Depletion voltage: Increase the depleted volume Low-resistivity ~ 3 Ωcm High-resistivity ~k Ωcm SiO P-Well Sensing diode N+ P+ Epitaxial Layer Substrate depleted volume P- P+ Larger depleted volumes: Accelerated charge collection, less diffusion Less charge smearing between pixels Aim: Full depletion of the epitaxial layer Dennis Doering: Status of radiation tolerance of MAPS CBM Coll Meeting GSI April 3 9 /7 /5

20 TOWER-Jazz-Process High-resistivity: Decrease of doping concentration in epitaxial layer. Depletion voltage: Increase the depleted volume Low-resistivity ~ 3 Ωcm High-resistivity ~k Ωcm SiO P-Well Sensing diode N+ P+ TOWER-Jazz-.8µm process - High-Resistivity -8kΩcm - Depletion voltage up to V Epitaxial Layer P- Substrate depleted volume Larger depleted volumes: Accelerated charge collection, less diffusion Less charge smearing between pixels P+ Modified preamplifier - Recharge diode - AC-coupled Aim: Full depletion of the epitaxial layer Dennis Doering: Status of radiation tolerance of MAPS CBM Coll Meeting GSI April 3 /7 /5

21 TOWER-Jazz.8µm CMOS process for imager The Sensor: PEGASUS (5) 8µm thick, 5µm pixel pitch, >kωcm epitaxial layer, V bias voltage Pegasus, T= + C Cd-9-source 3 Ag Lα One "seed" pixel Cd-9-source Cu-foil Ag K α,k β Counts [/4 e] 5 5 Cu Kα Cu Kβ Ag Kα Calibration peak 75 Ag Kβ Less charge smearing Larger depletion zone Collected energy [kev] Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 /7 /5

22 TOWER-Jazz.8µm CMOS process for imager The Sensor: PEGASUS (5) 8µm thick, 5µm pixel pitch, >kωcm epitaxial ayer, V bias voltage Pegasus, T= + C Cd-9-source 3 Ag Lα One "seed" pixel Depleted zone Cd-9-source Cu-foil Ag K α,k β Counts [/4 e] 5 5 Cu Kα Cu Kβ Ag Kα Calibration peak 75 Ag Kβ Less charge smearing Larger depletion zone Trigger on neighboring pixels still helps Collected energy [kev] Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 /7 /5

23 Non-linear response of the recharge diode Counts [/8 e] Literature: Cu-K α =847 ev Cu-K α =87 ev T= + C Cu-K α = 835 ev T= - C Cu-K α = 835 ev 6, 6,5 7, 7,5 8, 8,5 9, 9,5, Collected energy [kev] Counts [/8 e] T= + C T= - C σ + C =637eV σ - C =5eV 5 5,,5,,5,,5 3, 3,5 4, Collected energy [kev] Due to the non-linear response of the recharge diode at + C: - Limited energy resolution - Non-linear amplification Cooling to - C recommended Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 3 /7 /5

24 Cu-inlay Cd-9-source Cu-foil Ag K α,k β Ag K α,k β +Cu K α Counts [/8 e] (norm. to detected Ag Kα-Photons) Ag Lα Pegasus, T= - C Cd-9-source Cu Kβ Reference Cu-inlay Cu Kα =84 ev σ=ev Ag Kβ Collected energy [kev] Ag Kα Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 4 /7 /5

25 Conclusion CMOS-Sensors established in Black&White X-ray imaging Is there a possibility for Colored X-Ray imaging? Energy extracted in single photon counting Studied two CMOS-sensors: MIMOSA-9 and Pegasus Possible between 6 kev with an energy resolution of 9eV At room temperature or slightly cooled conditions Offers the possibility of colored X-ray images Limited by currently required long exposure time and low quantum efficiency Search for applications Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 5 /7 /5

26 Pegasus, T= - C Cd-9-source Counts [/8 e] (reference substracted) Ag Lα Cu Kα =84 ev σ=ev Cu Kβ Collected energy [kev] Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 6 /7 /5

27 U K 3 U F U F I Reset +3.3V K U SB I Leakage C U K U CDS =U F - U F /7

28 U K 3 U F U F U F I Reset +3.3V K U SB U F I Leakage Q Signal particle C U K U CDS =U F - U F /7

29 U K 3 U F U F U F +3.3V I Reset ΔI Small K U SB U F I Leakage C U K U CDS =U F - U F /7

30 U K 3 U F U F U F U F U F +3.3V I Reset ΔI Small K U SB U F I Leakage C U K U CDS =U F - U F /7

31 U K 3 U F U F U F U F U F U F U F I Reset +3.3V K U SB U F I Leakage C U K U CDS =U F - U F /7

32 U K 3 U F U F U F U F U F U F U F U F U F I Reset +3.3V K U SB U F I Leakage C U K U CDS =U F - U F /7

33 U K 3 U F U F U F U F U F U F U F U F U F U F +3.3V I Reset ΔI Large K U SB U F U F I Leakage Q Signal particle C U K U CDS =U F - U F /7

34 U =U K (Low I leak ) Current-voltage characteristic I Reset U =U K (Low I leak )+Q signal /C U 3 =U K (High I leak ) U 4 =U K (High I leak )+Q signal /C ΔI Small ΔI Large U U U 3 U 4 U SB =3.3V-U K /7

35 TOWER-Jazz.8µm CMOS process for imager Features: Thick epitaxial layer up to 3µm Aim: Full deple:on - High-Resis:vity >kωcm - Deple:on voltage >V The Sensor: PEGASUS (5) 8µm thick, 5µm pixel pitch, >kωcm epitaxial layer, V bias voltage Pegasus 4 n eq cm² T= -55 C Cd-9 Cd-9-source Cu-foil Ag K α,k β Ag K α,k β +Cu K α Counts (normalized to calibration peak) Without Cu-inlay With Cu-inlay Energy [kev] Depletion features good radiation hardness provided cooling Dennis Doering: CMOS-Sensors for energy-resolved X-ray imaging iworid June 5 35 /7 /5

Development of a Radiation Hard CMOS Monolithic Pixel Sensor

Development of a Radiation Hard CMOS Monolithic Pixel Sensor M. Battaglia 1,2, D. Bisello 3, D. Contarato 2, P. Denes 2, D. Doering 2, P. Giubilato 2,3, T.S. Kim 2, Z. Lee 2, S. Mattiazzo 3, V. Radmilovic