1st Edition

Semiconductor X-Ray Detectors

By B. G. Lowe, R. A. Sareen Copyright 2014
    624 Pages 16 Color & 343 B/W Illustrations
    by CRC Press

    624 Pages 16 Color & 343 B/W Illustrations
    by CRC Press

    Identifying and measuring the elemental x-rays released when materials are examined with particles (electrons, protons, alpha particles, etc.) or photons (x-rays and gamma rays) is still considered to be the primary analytical technique for routine and non-destructive materials analysis. The Lithium Drifted Silicon (Si(Li)) X-Ray Detector, with its good resolution and peak to background, pioneered this type of analysis on electron microscopes, x-ray fluorescence instruments, and radioactive source- and accelerator-based excitation systems. Although rapid progress in Silicon Drift Detectors (SDDs), Charge Coupled Devices (CCDs), and Compound Semiconductor Detectors, including renewed interest in alternative materials such as CdZnTe and diamond, has made the Si(Li) X-Ray Detector nearly obsolete, the device serves as a useful benchmark and still is used in special instances where its large, sensitive depth is essential.

    Semiconductor X-Ray Detectors focuses on the history and development of Si(Li) X-Ray Detectors, an important supplement to the knowledge now required to achieve full understanding of the workings of SDDs, CCDs, and Compound Semiconductor Detectors. The book provides an up-to-date review of the principles, practical applications, and state of the art of semiconductor x-ray detectors. It describes many of the facets of x-ray detection and measurement using semiconductors, from manufacture to implementation. The initial chapters present a self-contained summary of relevant background physics, materials science, and engineering aspects. Later chapters compare and contrast the assembly and physical properties of systems and materials currently employed, enabling readers to fully understand the materials and scope for applications.

    The Detector and Charge Sensitive Preamplifier: A System Overview
    The Transducer
    Why Semiconductors?
    Fermi-Dirac Statistics
    Doping of Semiconductors
    The p-n Junction Barrier
    Charge Generation by Radiation
    Pulse Height Analysis
    X-Ray Spectroscopy
    Leakage Current
    Typical Noise Values
    The FET
    Detector Response Function F(E)
    Categorization of Semiconductor Detectors
    The Lithium Drifted Silicon Detector (Si(Li))
    The Silicon Drift Detector (SDD)

    Detector Response Function
    The Hypermet Function
    Monte-Carlo Calculations
    Physical Processes and the Analytical Approach
    Peak Broadening - The Fano Factor
    Charge Collection Efficiency Function
    Generation of Spectral Response Function
    Charge-Loss Mechanisms
    Charge Gains

    Detector Artifacts
    Field Distortion
    The Spur
    Ghost Peaks
    Compton Scatter
    Absorption Edges
    Sum Peaks
    Electron Contamination

    Parameters Influencing ICC
    Diffused Junction Contacts
    Ion-Implanted Contacts
    Surface Barrier Contacts
    Low Injection Contacts
    Edge Termination of Contacts
    Radiation Damage

    Si(Li) X-Ray Detectors
    Manufacture of Si(Li) Detectors
    The Legacy of Contouring
    Losing the Process

    HPSi and HPGe X-Ray Detectors
    HPSi X-Ray Detectors
    HPGe X-Ray Detectors

    X-Ray Detectors Based on Silicon Lithography and Planar Technology
    Silicon p-i-n Diodes
    Avalanche Photo-diodes (APDs)
    Pixelated X-Ray Detectors (PXDs)

    CCD-Based X-Ray detectors
    Techniques of Scientific CCDs
    The Performance of MOS-CCD X-Ray Detectors
    The pn-CCD
    CCDs Summary

    Silicon Drift Detectors
    Concentric Ring SDD X-Ray Detectors
    Droplet SDD X-Ray Detectors
    SDD Performance
    SDD Manufacture
    SDD Summary

    Wide Band-Gap Semiconductors
    The Candidates
    General Comments on WBGS
    The Present Status of the WBGS X-Ray Detectors

    The History of Semiconductor X-Ray Detectors
    The Beginnings
    The Development of Materials during World War II
    1940-1960: Crystal Counters
    1940s: The Role of National Labs, Bell Telephone Labs, and other Corporations
    The Story of Silicon and Germanium
    Other Materials
    1960-66: Progress in Detector Manufacture and Spectroscopy
    Surface States and Nature’s Gift of SiO2
    Processing and Passivation
    1960s: The Evolution of Detector Geometries
    1960s: Lithium Compensation
    1960-1966: Amplifiers
    1966-71: Pulsed Optical Restore
    Applications on the Horizon
    The Companies
    1970s and 1980s: Evolution in the Commercial Environment
    1970s and 1980s: Low Energy EDXMA
    1987: The Kevex Quantum Window: Convenience verses Performance
    High Purity Germanium and Silicon
    1990s: HPGe X-Ray Detectors
    1990s: Bespoke FETs
    Convenience verses Performance: A New Approach
    SDD: The Influence of Nuclear Physics Again
    SDDs as X-Ray Detectors
    The SDD EDXRS Companies
    The Future


    Author of over 20 publications and the "conditioner" patent for Si(Li) X-Ray Detectors, B. G. Lowe holds a Ph.D from Liverpool University, UK. He has served as commonwealth education officer for University of Columbo, Sri Lanka; lecturer for University of Science-Malaysia, Penang, and North East Wales Institute of Higher Education, UK; chief physicist for Link Systems Ltd, London, UK; physics director, head of development, and senior scientist for Oxford Instruments, London, UK; and senior scientist for e2V Scientific, High Wycombe, UK. He also worked on the UK government-sponsored IMPACT project and CdZnTe detectors at Leicester University, UK.

    Author of over 15 publications and two patents, R. A. Sareen holds a Ph.D from Manchester University, UK. He has served as research scientist for Ortec, Oak Ridge, Tennessee, USA; founder of Nuclan Ltd, London, UK; technical, managing, main board, and executive director for Link Systems Ltd, London, UK (now Oxford Instruments) and UEI London, UK; researcher at Manchester University; and shareholder in Link Systems Ltd, Gresham Power Electronics and Gresham Scientific Instruments Ltd, Salisbury, UK, and Camscan, Cambridge, UK. A Royal Microscopical Society and Institute of Physics fellow, he has liaised with several UK government departments, including security services, and participated in nuclear strategy and homeland security committees.