Radiation damage in silicon exposed to high-energy protons

• Published in: Physical review. B, Condensed matter and materials physics Condensed matter and materials physics, 2006-04, Vol.73 (16)
• Main Authors: Davies, Gordon, Hayama, Shusaku, Murin, Leonid, Krause-Rehberg, Reinhard, Bondarenko, Vladimir, Sengupta, Asmita, Davia, Cinzia, Karpenko, Anna, Department of Physics, King's College London, Strand, London WC2R 2LS, United Kingdom and CCLRC Daresbury Laboratory, Daresbury, Warrington, Cheshire, WA4 4AD, Joint Institute of Solid State and Semiconductor Physics, National Academy of Sciences of Belarus, 220072 Minsk, Department of Physics, Martin Luther University, 06108 Halle, Department of Physics, Visva-Bharati Central University, Santiniketan-731235, Department of Electronic Engineering, Brunel University, Uxbridge UB8 3PH
• Format: Article
• Language: English
• Subjects: ACTIVATION ENERGY; ANNEALING; ANNIHILATION; CARBON; COMPARATIVE EVALUATIONS; CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; DEEP LEVEL TRANSIENT SPECTROSCOPY; EV RANGE; GEV RANGE; INFRARED SPECTRA; INTERSTITIALS; OXYGEN; PHOTOLUMINESCENCE; PHYSICAL RADIATION EFFECTS; POSITRONS; PROTONS; SEMICONDUCTOR MATERIALS; SILICON; TEMPERATURE RANGE 0273-0400 K; TRAPPING; X CENTERS
• ISSN: 1098-0121; 1550-235X
• DOI: 10.1103/PHYSREVB.73.1

Photoluminescence, infrared absorption, positron annihilation, and deep-level transient spectroscopy (DLTS) have been used to investigate the radiation damage produced by 24 GeV/c protons in crystalline silicon. The irradiation doses and the concentrations of carbon and oxygen in the samples have been chosen to monitor the mobility of the damage products. Single vacancies (and self-interstitials) are introduced at the rate of {approx}1 cm{sup -1}, and divacancies at 0.5 cm{sup -1}. Stable di-interstitials are formed when two self-interstitials are displaced in one damage event, and they are mobile at room temperature. In the initial stages of annealing the evolution of the point defects can be understood mainly in terms of trapping at the impurities. However, the positron signal shows that about two orders of magnitude more vacancies are produced by the protons than are detected in the point defects. Damage clusters exist, and are largely removed by annealing at 700 to 800 K, when there is an associated loss of broad band emission between 850 and 1000 meV. The well-known W center is generated by restructuring within clusters, with a range of activation energies of about 1.3 to 1.6 eV, reflecting the disordered nature of the clusters. Comparison of the formation of the X centers in oxygenated and oxygen-lean samples suggests that the J defect may be interstitial related rather than vacancy related. To a large extent, the damage and annealing behavior may be factorized into point defects (monitored by sharp-line optical spectra and DLTS) and cluster defects (monitored by positron annihilation and broadband luminescence). Taking this view to the limit, the generation rates for the point defects are as predicted by simply taking the damage generated by the Coulomb interaction of the protons and Si nuclei.