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Défauts induits par l'implantation d'hélium dans les matériaux à base silicium

Abstract : The work presented in this Ph.D thesis has been done in the Laboratoire de Métallurgie Physique at the University of Poitiers and in the group Defects in Materials of the Interfaculty Reactor Institute at the Technological University of Delft (Netherlands).
Materials requirements for semiconductors used in microelectronics become continuously more severe. Indeed, impurities and crystallographic defects can strongly modify the characteristics of electronic devices and thus must be fully controlled in order to improve device performance. Recently, helium induced cavities in silicon wafers have received considerable attention due to their efficiency as gettering sites for metallic impurities. Cavities in silicon are usually formed by high dose He ion implantation followed by annealing at high temperatures. Even if silicon plays a major role in the development of today semiconductor device technology, silicon carbide is one of the most promising candidate to extend future microelectronic applications.
In this thesis TEM (Transmission Electron Microscopy) investigations of defects introduced by helium implantation in silicon and in silicon carbide are presented. Additional techniques such as THDS (Thermal Helium Desorption Spectrometry) and XRD (X-Ray Diffraction) have been also used. In case of medium dose MeV implantation in silicon, an alternative route for bubble formation is found, leading to numerous interstitial-type extended defects. We have shown that the dose-rate strongly influence the formation of bubbles and of related defects. Further studies on the effects of annealing time and implantation temperature have been performed. Implantation at room temperature of high dose helium ions into SiC leads not only to the formation of small bubbles but also to amorphization. At 1500°C annealing recrystallization take place leading to polytypisme and to the enlargement of the cavities. THDS studies on bubbles precursors in SiC are also presented.
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Contributor : Erwan Oliviero <>
Submitted on : Tuesday, October 17, 2006 - 1:31:50 PM
Last modification on : Thursday, March 28, 2019 - 2:04:04 PM
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  • HAL Id : tel-00107085, version 1



Erwan Oliviero. Défauts induits par l'implantation d'hélium dans les matériaux à base silicium. Physique [physics]. Université de Poitiers, 2001. Français. ⟨tel-00107085⟩



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