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He induced nanovoids for point-defect engineering in B-implanted crystalline Si.
- Source :
-
Journal of Applied Physics . 1/15/2007, Vol. 101 Issue 2, p023515-N.PAG. 8p. 1 Black and White Photograph, 6 Graphs. - Publication Year :
- 2007
-
Abstract
- In this paper we present a systematic study on the formation of He ion implantation induced nanovoids in Si and how they influence the self-interstitial (Is) supersaturation, thus affecting the diffusion and electrical activation of implanted boron in crystalline silicon. We implanted He ions into (100)-oriented Si wafers, with doses ranging from 5×1015 to 8×1016 He ions/cm2 and energies ranging from 25 to 110 keV. Then, we implanted B ions (12 keV, 5×1014 ions/cm2). All samples were annealed at 800 °C in N2 atmosphere. We demonstrated the role of nanovoids in reducing B diffusion already at the first stages of postimplantation annealing. The effect has been attributed to the Is trapping by the nanovoids that forces B to assume a boxlike profile. Moreover, we studied the nanovoid distribution as a function of He-implanted dose and energy, demonstrating, by means of Cu gettering experiments, the beneficial effect of increasing dose or decreasing energy of He implantation on the B diffusion and electrical activation. In fact, if the nanovoid density is high in the proximity of implanted B, implantation-related damage can annihilate at the internal dangling bonds of nanovoids, thus consuming the nanovoid layer. The potential of He coimplantation as a method for controlling point-defect distributions in crystalline Si is presented and critically discussed. [ABSTRACT FROM AUTHOR]
- Subjects :
- *HELIUM
*IONS
*DIFFUSION
*PROPERTIES of matter
*SILICON
*ION implantation
Subjects
Details
- Language :
- English
- ISSN :
- 00218979
- Volume :
- 101
- Issue :
- 2
- Database :
- Academic Search Index
- Journal :
- Journal of Applied Physics
- Publication Type :
- Academic Journal
- Accession number :
- 23878069
- Full Text :
- https://doi.org/10.1063/1.2427101