Diamond Detectors

Diamond Detectors Introduction to DDL Facilities / Investments Markets / Applications Partnerships / Projects DDL Proprietary Contact Technology Alex Brown Sales & Marketing Diamond Detectors Limited

Introduction to DDL Press release Thursday 3rd May 2007 “Element Six Spins Out New Company to Develop Diamond Detectors……. June 2007, DDL Moves into new office, Poole, Dorset 2008, BAE systems acquires 50% share in DDL Diamond Detectors Limited

Facilities / Investments “From Concept through Design & Prototype to Manufacture” Expertise Material Processing Lapping & Polishing Processes Laser Dicing & Shaping Metallization (e.g. Ti, Pt, Au, Al..) Neutron Scintillation Coating 6LiF Lithography (sandwich,strips,pixels) Die Fabrication and Test Die/Wire Bonding. Packaging Characterisation. Electronics Development Facilities Diamond Lab Laser Lab Chemistry Lab Lithography and Assembly Clean rooms. (class 1000 & 10000) Design Suite Diamond Detectors Limited

Facilities / Investments “From Concept through Design & Prototype to Manufacture” Concept - Design Manufactured Devices Diamond Detectors Limited

Facilities / Investments Device Fabrication “From Concept through Design & Prototype to Manufacture” Magnetron Sputtering‏ Quazer Laser Dicing‏ Laser cutting, dicing & sputtering system Optical Profiler NT9100‏ Semi Automatic Scaife Sputtering & E-Beam Evap‏oration & Milling Lapping, Polishing and Semi-automatic scaife Metallisation Diamond Detectors Limited ball bonding (K&S 4124)‏‏ Aluminium & Gold wedge and ball wire bonding Dage 4000 Wire bond pull tester‏ Universal wedge bonder (K&S 4523) ‏ Wire Bonding (Strip Detector)

Facilities / Investments “From Concept through Design & Prototype to Manufacture” Characterisation Typical process specifications :- Polycrystalline standard polish Ra < 20nm Polycrystalline detector polish Ra < 12nm Polycrystalline Super polish Ra < 5nm Single crystal detector polish Ra < 1nm Diamond Detectors Limited

Manufacturing 2009 update / 2010 plans Facilities / Investments • 2010 plans • Q1, automated ccd measurement capability • Yield improvement on 50 and 100 micron plates enables standard pricing • Batch production of standard products • Teething issues with new equipment resolved – increases rate of development • 1 micron lithography tools under evaluation • (or 120k budgeted for spray coater) • Develop techniques to hold diamond during scaife • 2009 update • Licensed CAT-5 site (Sr-90 37MBq) • Alpha, Beta, Gamma and X-ray sources • Dicing technique permits two 100 micron plates from single crystal • Scaifing specialist improves single crystal polishing – polishing lines removed • Laser Shaping, Dicing & Vacuum sputtering (including ion beam polishing) teething problems (equipment failures) resolved • New Jigs & Fixtures 2009 - under-resourced, equipment issues (largely addressed), yield issues, significant investments, increase in capabilities 2010 – yield improvements, significant investments, standard products, increase in capabilities Diamond Detectors Limited

Facilities / Investments Intrinsic Polycrystalline Intrinsic single crystal Diamond Detectors Limited

High Tech Application of Diamond • Diamond Detectors focus includes... • Diamond Wide Band Gap Detectors. (solid state ionizing chamber)‏ • Diamond Sensors (Electro-chemical and Bio applications)

HEP Radiation detectors employed in beam lines and other applications with synchrotrons, colliders and cyclotrons. Also used in satellite and stellar instrumentation Applications for CVD Diamond • Neutron & α detection • Radiotherapy, particles and x-ray • Beam monitoring & diagnostics • Precision tracking (inner layer) LHC / SLHC • TOF • Energy resolution • Beam positioning • Heavy ion Diamond Detectors Limited

Electronic Instrumentation forDDL’s CVD Diamond Detector • DDL’s CVD Diamond detectors with CAEN electronic solutions: N1470 4 Channel Programmable NIM HV Power Supply DT5724 4 Channel 14 bit 100 MS/s Digitizer A422A Charge Sensitive Preamplifier

Medical Example Application of EL SC CVD Diamond: Intensity Modulated Radiation Therapy • Before treatment of patient: • Dummy run with detector • Detector placed in tissue equivalent material to assess beam profile • Detector must be moved several times to collect enough information - an array of detectors would be ideal • Treatment: • Patient typically receives 3 treatments, each from a different angle of entry Diamond Detectors Limited

Nuclear Applications X-ray, Alpha, Beta, Gamma and Neutron radiation detectors for dose / spectroscopy applications in nuclear power and reprocessing plants Applications for CVD Diamond α / β in air α spectroscopy α / β contamination Neutron X-Ray Solid State Ion Chamber Diamond Detectors Limited

Oil & Gas Polycrystalline & Single-Crystal Solid-State Ionizing Chambers Diamond with its wide band gap (5.47ev) and resilient properties makes it an ideal choice for applications working in hostile environments. As a wide band gap semi-conductor the material can operate at elevated temperature and in high pressure, high vibration environments Solid State /Ionizing Chamber & Electrode / Electro-Chemical properties • High temperature operation (>>300C, negligible dark current pA scale) • Extremely low leakage or background currents. • High electron and hole motilities (fast operation in counting modes) • High break down. • High thermal conductivity • Radiation hard. • Solar blind (response to deep UV, soft and hard x-rays, particles and neutrons) • Tissue equivalent dose measurement (low Z =6) • Spectroscopic measurements (with single crystal) • Chemical inertness. • Wide electro-chemical window • Bio-compatible (non-fouling) • Mechanical hardness Diamond Detectors Limited

Projects • Mike Bentley, York University , (Fair beamline Instrumentation) • Richard Hugtenburg, Swansea University, (Medical Dosimeters) • Prof. Peter Winlove, Exeter University, (Knowledge Transfer Program for diamond based bio/chemical sensors) • Japp Velthuis, Bristol University, (RD42 member) Case Studentship for GHz fast counting applications in Civil Nuclear and Particle Therapy • Darren Caruana, UCL, BDD electrodes for pollen identification and counting • Various industrial partners across the DDL markets Diamond Detectors Limited

DDL Proprietary Contact Technology Metallization (Electrical Contact Fabrication on CVD Diamond)‏ Diamond Detectors Limited (DDL) has patented an innovative metallization technique to maximize CVD diamond performance. Here we seek to highlight the issues and describe the solution. The development of CVD Diamond has made possible many new applications for detecting and sensing. However, manufacturing semiconductor devices in diamond present some interesting challenges due to diamond’s unique characteristics. Traditional or inadequate contact fabrication may result in poor mechanical adhesion, polarization effects and unrepeatable results. Mechanical Adhesion Specifically, the mechanical adhesion of the metal chosen as electrode on the diamond surface. A flatter smoother surface presents fewer adhesion points. When a metal is thermally evaporated on diamond it may not adhere and it could peel off after a short period of time with the consequent deterioration of the electrical signal measured and therefore a decrease in the lifetime of the device. Mechanical adhesion is a function of the diamond / contact interface. Polarization Effects Polarization phenomena occur when electric currents pass through diamond if the electrical contact is not able to extract and inject electrons fast enough. In this case, the neutrality of the crystal after the passage of ionizing nuclear radiations is not restored in the time interval between two consecutive events. As a result, charge accumulation occurs within the crystal and immobile carriers establish an electric field which acts in a direction opposite to the applied field produced by the external bias voltage V. The minimisation of polarization effects requires optimal injecting contacts. Repeatable Results If a device is to be commercially viable it should be consistent and stable in a variety of environmental conditions. Requires stable and resilient contacts. Historically, there have been three main approaches to fabricate good electrical contacts on diamond: 1. Damaging the diamond surface in order to disrupt the sp3 bonding. 2. Using carbide forming metals like titanium or chromium to create a hybrid metal-diamond interface material . 3. Doping of diamond during growth or using ion implantation. For example, to prepare good injecting contacts, several metals were used by Kozlov et al., for hole injection they used Ag, Au, Pt or C deposition, aluminium or boron implantation, for electron injection P, Li or C. Galbiati et al. IEEE TNS VOL 56 N 4 AUGUST 2009 p1863

DDL Proprietary Contact Technology Metallization (Electrical Contact Fabrication on CVD Diamond)‏ Galbiati et al. IEEE TNS VOL 56 N 4 AUGUST 2009 p1863

DDL Proprietary Contact Technology Metallization (Electrical Contact Fabrication on CVD Diamond)‏ DDLs solution To address the polarization issues mentioned above and to provide a method for forming an ohmic electrode that is also durable and stable for applications in diamond radiation detectors and diamond electronics, Diamond Detectors Ltd have developed and tested an innovative electrical contact using a very thin diamond like carbon layer. Diamond-like carbon (DLC) is a form of amorphous carbon between diamond and graphite, containing significant portion of sp3 bonded atoms in the matrix. DLC films can be grown when carbon is deposited under energetic (~10-100eV) bombardment, where the instantaneous local high temperature and pressure induce a proportion of carbon atoms to bond as diamond. The conditions for DLC deposition are obtained during a variety of methods, including CVD, laser ablation, magnetron sputtering, cathodic arc, and ion beam deposition. This innovative contact consists of a very thin (1-3 nm) diamond-like carbon film which is formed on a diamond substrate by means of Argon magnetron sputtering from a carbon target. The very thin DLC layer allows for the injection of both holes and electrons in the diamond substrate. Also, the DLC layer becomes a seed for the sputter deposition of high work function noble metals (Pt, Au) which allow metals to cohere to the diamond surface. As platinum and gold have a higher work function than diamond this permits electrons present at the diamond surface to be driven towards the noble metals via quantum mechanical tunnelling through the thin DLC layer acting as a quantum mechanical tunnelling junction. DDL’s patented metallization technique provides a manufacturable, high adherence diamond / contact interface with minimal polarization effect while maximizing stability and contact resilience. 22 Galbiati et al. IEEE TNS VOL 56 N 4 AUGUST 2009 p1863

DDL Proprietary Contact Technology Dark Current Characteristics 23 Galbiati et al. IEEE TNS VOL 56 N 4 AUGUST 2009 p1863

REFERENCES: Bergonzo et al., Diamond and Related Materials, Volume 10, Issues 3-7, March-July (2001), 631-638 J.H. Kaneko et al. / Nuclear Instruments and Methods in Physics Research A 505 (2003) 187–190 Pomorski et al., Phys. Stat. Sol. (a) 202, No. 11 (2005)‏ Gianluca Verona-Rinati “Single crystal CVD diamond neutron detectors in a p-type/intrinsic/metal layered structure” , http://www-norhdia.gsi.de/talks/4th/G_Verona-Rinati.pdf Galbiati et al. “Performance of Monocrystalline Diamond Radiation Detectors Fabricated Using TiW, Cr/Au and a Novel Ohmic DLC/Pt/Au Electrical Contact” IEEE TNS VOL 56 N 4 AUGUST 2009 p1863 Angelone et al.: “NEUTRON DETECTORS BASED UPON ARTIFICIAL SINGLE CRYSTAL DIAMOND” IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 56, NO. 4, AUGUST 2009 pp.2275-2279 Almaviva et al.: “Thermal and fast neutron detection in chemical vapor deposition single-crystal diamond detectors”J. Appl. Phys. 103, 054501 2008 G.J. Schmid et al. “A neutron sensor based on single crystal CVD diamond”, Nuclear Instruments and Methods in Physics Research A 527 (2004) 554–561 M. Pillon, M. Angelone, A.V. Krasilnikov, Nucl. Instr. and Meth. Phys. Res. B 101 (1995) 473.

Thank you Diamond Detectors Limited

Collaborating Opportunities ? • Custom design and prototype manufacture. Let us help you develop a resilient detector/sensor technology for your application using our design tools, facilities and experience in collaboration with your R&D team. • Prototype to Product (cost engineering, batch processing and test) Diamond Detectors Limited

Application Diamond Sensors Bio-and Chemical Sensing • Wide electrochemical window • Extremely low background current. • Bio-Compatible (non-fouling) • Very stable surface (Chemically inert)‏ • Varied surface terminations possible • Mechanically robust

Application Diamond Sensors • Electro-chemical sensors (MEA, trace element analysis)‏ (Mining, Automotive, Medical, Food, Water, Environmental, Emissions …..)‏ • PH-Sensors • Temperature-Sensors • Conductivity • Replacement of Mercury Electrodes (Mercury ban widens)‏ Next Generation (addressable MEA) under consideration

Diamond Detectors