Cracks and blisters formed close to a silicon wafer surface by He-H co-implantation at low energy

Journal Article · Mon Dec 28 04:00:00 EST 2015 · Journal of Applied Physics

DOI:https://doi.org/10.1063/1.4938108· OSTI ID:22493103

Darras, F. -X.; Claverie, A. ^[1]; Daghbouj, N. ^[1]; Fnaiech, M. ^[2]

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1. CEMES-CNRS and Université de Toulouse, 29 rue J. Marvig, 31055 Toulouse (France)
2. Faculté des Sciences de Monastir, Université de Monastir, Monastir (Tunisia)

We have studied the effect of reducing the implantation energy towards low keV values on the areal density of He and H atoms stored within populations of blister cavities formed by co-implantation of the same fluence of He then H ions into Si(001) wafers and annealing. Using a variety of experimental techniques, we have measured blister heights and depth from the surface, diameter, areal density of the cracks from which they originate as functions of implantation energy and fluence. We show that there is a direct correlation between the diameters of the cracks and the heights of the associated blisters. This correlation only depends on the implantation energy, i.e., only on the depth at which the cracks are located. Using finite element method modeling, we infer the pressure inside the blister cavities from the elastic deformations they generate, i.e., from the height of the blisters. From this, we demonstrate that the gas pressure within a blister only depends on the diameter of the associated crack and not on its depth position and derive an analytical expression relating these parameters. Relating the pressure inside a blister to the respective concentrations of gas molecules it contains, we deduce the areal densities of He and H atoms contained within the populations of blisters. After low-energy implantations (8 keV He{sup +}, 3 keV H{sup +}), all the implanted He and H atoms contribute to the formation of the blisters. There is no measurable exo-diffusion of any of the implanted gases, in contrast to what was assumed at the state of the art to explain the failure of the Smart-Cut technology when using very low energy ion implantation for the fabrication of ultra-thin layers. Alternative explanations must be investigated.

• OSTI ID: 22493103
• Journal Information: Journal of Applied Physics, Journal Name: Journal of Applied Physics Journal Issue: 24 Vol. 118; ISSN JAPIAU; ISSN 0021-8979
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ANNEALING
BLISTERS
CONCENTRATION RATIO
CRACKS
DEFORMATION
DENSITY
FINITE ELEMENT METHOD
HELIUM
HELIUM IONS
HYDROGEN
HYDROGEN IONS 1 PLUS
ION IMPLANTATION
KEV RANGE
SILICON
THIN FILMS