Status of 3D double sided detector fabrications and their applications at CNM-IMB

1. Status of 3D double sided detector fabrications and their applications at CNM-IMB G. Pellegrini D. Bassignana, JP Balbuena, E. Cabruja, C. Fleta, C.Guardiola, M. Lozano, D. Quirion, M.Ullan

2. Outline • Description of the technology • Activity on 3D detectors: • FE-I4 Atlas pixels for IBL and atlas upgrade • 3d ultra-thin for neutron detection and dosimetry

3. Fabrication of 3D detectors at CNM-IMB clean room facilities • Technology: • 4” silicon wafer • 285um FZ high resistivity wafers (n and p- types) • All fabrication done in-house • ICP etching of the holes: Bosch process, ALCATEL 601-E • Holes partially filled with 3 µm LPCVD poly doped with P or B • Holes passivated with 2 µm TEOS SiO2 • Double side process proposed by CNM in 2006 • Fabrication of 3D double sided in 2007. • Fabrication of ultra thin U3DTHIN in 2007. • First fabrication of 3D single side in 2008. • In 2010 CNM started the fabrication 235um thick wafers for the IBL. First proposed by Parker et al. Nucl. Instr. Meth. A, 395 (1997) 328 G. Pellegrini at the Second Trento Workshop on Advanced Silicon Radiation Detectors, Trento,Italy, 2006.

4. Technologies CNM-IMB has developed both technologies • Array of electrode columns passing through substrate • Electrode spacing << wafer thickness (e.g. from 10m to >300m) Double sided 3D Single sided

5. Technology Few years of technology development: double sided

6. Cross section P-stop Passiv Al Polysilicon n+ 13um

7. 3D FE-I4 Atlas pixels for IBL Atlas pixels, FE-I3 and new FE-I4 fabrication and irradiation for Insertable B-Layer and testbeam. In the framework of the Atlas 3D collaboration (http://test-3dsensor.web.cern.ch/test-3dsensor/). Common layout designed in the framework Atlas 3D collaboration (CNM,FBK,SINTEF, Stanford). New FE-I4 design (2x2 cm2). Qualification run finished and tested (please see S. Grinstein´s talk) First full fabrication run finished, Second run will finish by December 2011. Third run ongoing.

8. Electrical characterization Bow: 60.8µm # class A detectors: 8 # class B detectors: 0 # class C detectors: 0

9. Radiation hardness • 3D detectors tested up to 2*1016 1MeV neq cm-2. Measured with Alibava System at Glasgow University. LHCb speed bi-polar amplifier (25ns peaking time) Charge multiplication! 3D measured at ~300V Planar measured at 1000V 150V

10. UBM deposition For IBL the UBM is deposited on all wafers at IZM in Germany before the flip chip. Under bump metallization CMN and IFAE have developed the technology for UBM deposition Ni/Au and Cu and the flip chip process with SnPb and SnAg bumps. Electroplating for 50µm-pitch Indium: Under development: FlipChip Flip chip machine: FC150 Bump reflow: ATV SRO702 10

11. Status of production run Delivered Dec. 2011 March. 2012 + back up

12. What can be improved for HEP? • Reduce the dead area at the detector • edges. Laser-Scribing and Al2O3 • Sidewall Passivation of P-Type • Sensors: (see M. Christophersen´s talk) • Negative charges induced by Al2O3 deposited by ALD process, isolate the sidewall surface cut in p-type wafers reducing surface current. 12

13. Other applications: Neutron Dosimetry Radiotherapy treatments with LINACs are widely extended worldwide to treat the cancerous tissue. However, when the primary electron beam collides with the target (Pb or W) to produce the photons for the treatment, neutrons are produced by the photo‐neutron reaction within the heavy materials at the head LINAC at applied energies higher than 8 MeV. This out‐of‐field radiation can deliver an undesirable and damaging peripheral secondary dose outside the treated organ that may induce other cancers. 13

14. Ultra Thin 3D detectors The device is a novel ultra‐thin silicon detector with only 10μm thick active volume, fabricated on a SOI wafer. The collecting electrodes are columns etched through the silicon instead of being implanted on the surface like in the standard planar technology, allowing lower capacitance. The neutron sensitive element is a boron‐based converter layer deposited on the front side of the U3DTHIN which detects the charged particles produced via the 10B(n,alpha)7Li reaction. Thin membrane 10B-compound (C2B10H12) 300um Etched backside 14

15. Design and characterization Thin pads Thick pads 1 2 1 4 1 5 8 Thin strips 2 6 7 2 3 4 3 4 wafers fabricated and all working 15

16. Measurements at LINAC The adapted U3DTHIN detects neutrons were placed inside the radiotherapy rooms to simulate patient irradiation: •Low γ–ray absorption •Good γ/n discrimination rate •Linear response •No pile‐up of signal Gamma rejection •Elekta at 6MV&15MV •10x10 cm2 field •Distance from setup to isocenter: 3.8m, h=1.6m •400 MU(*) •Threshold: 200 keV MU: a Monitor Unit is a measure of the machine output of a linear accelerator in radiation therapy which is calibrated to deliver an absorbed dose under particular conditions, e.g. 100 MU gives 1 Gray at 100 cm SSD for a 10x10 cm2 field. 16

17. European project FP7 REWARD The REWARD project will develop portable, intelligent radiation detectors (silicon 3D and planar CdTe) that can determine the flux and energy of the incoming radiation, as well as their own location. The monitoring tags of the REWARD system will be installed in law enforcement vehicles or other mobile or fixed stations and will send their location and measurement data to a central monitoring station if an abnormal situation is detected. Prevention of: nuclear terrorism, lost radioactive sources, radioactive contamination or nuclear accidents • CNM-CSIC (SP) Coordinator • Sensing & Control Systems S.L. (Sp) • Vitrociset S.p.A (I) • Universität Freiburg (D) • Instituto Tecnológico e Nuclear (Pt) • XIE. X-ray Imaging Europe (D) • EDISOFT (Pt) • Civil Protection Unit of Campania (I) Real-time Wide-Area Radiation Surveillance System

18. Thanks for your attention

19. P-type holes 19

20. References of 3D detectors • Comparative measurements of highly irradiated n-in-p and p-in-n 3D silicon strip detectors, Nuc. Instr. Meth. A, Vol 659, Issue 1, 11 December 2011, Pages 272-281. • Precision scans of the Pixel cell response of double sided 3D Pixel detectors to pion and X-ray beams, Journal of Instrumentation (JINST), 6 P05002, 2011. (doi:10.1088/1748-0221/6/05/P05002). • Beam Test Measurements With Planar and 3D Silicon Strip Detectors Irradiated to sLHC Fluences”, IEEE Trans. Nucl. Sci., vol. 58, no. 3, pp. 1308-1314, 2011. • 3D Medipix2 detector characterization with a micro-focused X-ray beam: NIM A In Press, Corrected Proof, Available online 7 July 2010. • Synchrotron Tests of a 3D Medipix2 X-Ray Detector: TNS IEEE Volume: 57 , Issue: 1 , Part: 2 , Publication Year: 2010 , Page(s): 387 – 394. • Beam Test Measurements With 3D-DDTC Silicon Strip Detectors on n-Type Substrate : TNS IEEE Volume: 57 , Issue: 5 , Part: 3 , Publication Year: 2010 , Page: 2987 – 2994. • Fabrication and simulation of novel ultra-thin 3D silicon detector: NIM A Volume 604, Issues 1-2, 1 June 2009, Pages 115-118. • 3D silicon strip detectors: NIM A Volume 604, Issues 1-2, 1 June 2009, Pages 234-237. • Charge sharing in double-sided 3D Medipix2 detectors: NIM A Volume 604, Issues 1-2, 1 June 2009, Pages 412-415. • X-ray detection with 3D Medipix2 devices: NIM A Volume 607, Issue 1, 1 August 2009, Pages 89-91. • Charge collection studies of heavily irradiated 3D double-sided sensors : Nuclear Science Symposium Conference Record (NSS/MIC), 2009 IEEE. • Design, simulation, production and initial characterisation of 3D silicon detectors. NIM A Volume 598, Issue 1, 1 January 2009, Pages 67-70. • First double-sided 3-D detectors fabricated at CNM-IMB: NIM A Volume 592, Issues 1-2, 11 July 2008, Pages 38-43. • Ultra radiation hard silicon detectors for future experiments: 3D and p-type technologies : Nuclear Physics B - Proceedings Supplements, Volume 172, October 2007, Pages 17-19. • Development, simulation and processing of new 3D Si detectors: NIM A Volume 583, Issue 1, 11 December 2007, Pages 139-148 • Simulation and test of 3D silicon radiation detectors: NIM A Volume 579, Issue 2, 1 September 2007, Pages 642-647. • A New Dimension to Semiconductor Detectors in High Energy Physics and Medical Imaging”, Nucl. Instr. and Meth. 2003, A Volume 513, Issues 1-2, Pages 345-349. • Technology Development of 3D Detectors for Medical Imaging”, Nucl. Instr. and Meth. 2003 A Volume 504, Issues 1-3, Pages 149-153. • Study of Irradiated 3D Detectors” Nucl. Instr. and Meth., 2003, A Volume 509, Issues 1-3, pp 132-137. • “Technology Development of 3D Detectors for High Energy Physics and Imaging”, Nucl. Instr. and Meth., 2002, A Volume 487, pp. 19-26. • The work on 3D detectors has been done in collaboration with different high energies institutes expert in device characterization: Glasgow University, Diamond light source, Freiburg University, Brookhaven National Lab, IFIC Valencia, IFAE Barcelona.