Radiation Environments and Damage in Silicon Semiconductors

Abstract

InSilicon is the active material of radiation detectors and the basic material of electronic devices used in the fabrication and development of electronic circuits. The present technology evolves toward the creation of faster and less power consuming devices of increasingly small sensitive volume and higher density circuits, achieving, now, sub-micron technology with an increase of the number of memory elements. These devices are then used for applications of large to very large scale integration (VLSI) in several fields including particle physics experiments, reactor physics, nuclear medicine and space. Many fields of application present adverse radiation environments that may affect the operation of the devices. These radiation environments are described in Sect. 4.1. These environments are generated by i) the operation of the high-luminosity machines for particles physics experiments, an example is the Large Hadron Collider (LHC) , ii) the cosmic rays and trapped particles of various origins in interplanetary space and/or Earth magnetosphere and iii) the operation of nuclear reactors. Their potential threats to the devices operation, in terms of damage by displacement (radiation-induced damage), are also described in that section. A review of the characteristics of space, high-energy and nuclear radiation environments and of physical processes inducing damages in silicon semiconductor operated in radiation environments was provided by Leroy and Rancoita (2007).The generation and type of damage are linked to processes of energy deposition. The interaction of incoming particles with matter results into two major effects: the collision energy-loss and atomic displacement, which are treated in the chapter on Electromagnetic Interaction of Radiation in Matter. Interactions of incoming particles, which result in the excitation or emission of atomic electrons, are referred to as energy-loss by ionization or energy-loss by collisions. The non-ionization energy-loss (NIEL) processes are interactions in which the energy imparted by the incoming particle results in atomic displacements or in collisions, where the knock-on atom does not move from its lattice location and the energy is dissipated in lattice vibrations. The energy deposition by non-ionization processes is much lower (except for neutrons) than that by ionization. However, bulk-damage phenomena result mostly from atomic displacement deposition-mechanisms, the so-325 Principles of Radiation Interaction in Matter and Detection Downloaded from www.worldscientific.com by DEAKIN UNIVERSITY on 10/12/15. For personal use only. Principles of Radiation Interaction in Matter and Detection Downloaded from www.worldscientific.com by DEAKIN UNIVERSITY on 10/12/15. For personal use only. Radiation Environments and Damage in Silicon Semiconductors 327ing the main modifications of silicon radiation-detectors and devices after irradiations. These latter are discussed in Sect. 6.8 and Chapter 7, respectively. Finally, it has to be remarked that an extended treatment -compleme...