Transient enhanced diffusion in preamorphized silicon: the role of the surface

Cowern, N.E.B.; Alquier, Daniel; Omri, M.; Claverie, A.; Nejim, A.

doi:10.1016/s0168-583x(98)00678-8

Cited by 55 publications

(35 citation statements)

References 15 publications

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“…3 ͑ii͒ As the excess interstitials overlap strongly with the as-implanted B profile, the EOR defects that are formed may consist of BICs rather than predominantly self-interstitial defects.…”

Section: ͑I͒mentioning

confidence: 99%

“…During annealing, Si interstitials are released from the EOR defect band. Their coupling with B leads to transient enhanced diffusion ͑TED͒ and boron-interstitial cluster ͑BIC͒ formation, leading to increased junction depth and reduced dopant electrical activation, 3,4 respectively. One promising way to overcome these problems is to reduce the coupling between interstitials and B atoms by annealing for a short time at high temperature.…”

mentioning

confidence: 99%

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Surface proximity and boron concentration effects on end-of-range defect formation during nonmelt laser annealing

Sharp

Smith

Webb

et al. 2008

Applied Physics Letters

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The effects of surface proximity and B concentration on end-of-range defect formation during nonmelt laser annealing in preamorphized silicon have been studied. These effects were analyzed by observing the activation and diffusion of an ultrashallow B implant, using Hall effect and secondary ion mass spectrometry measurements. By adjusting the preamorphizing implant and laser annealing conditions, B deactivation and diffusion were minimized, resulting in a sheet resistance of ϳ600 ⍀ / sq with a 16 nm junction depth. This is attributed to a combination of enhanced dissolution of end-of-range defects and preferential formation of B-interstitial clusters due to the surface proximity and high B concentration, respectively.

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Section: ͑I͒mentioning

confidence: 99%

mentioning

confidence: 99%

Surface proximity and boron concentration effects on end-of-range defect formation during nonmelt laser annealing

Sharp

Smith

Webb

et al. 2008

Applied Physics Letters

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“…As is well known, 15 the recombination length at the surface, L 1 , is less than a few nanometers during TED and can certainly be neglected in comparison to the thickness d. We therefore have as a good approximation…”

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confidence: 93%

Boron deactivation in preamorphized silicon on insulator: Efficiency of the buried oxide as an interstitial sink

Hamilton

Kirkby

Cowern

et al. 2007

Applied Physics Letters

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Preamorphization of ultrashallow implanted boron in silicon on insulator is optimized to produce an abrupt boxlike doping profile with negligible electrical deactivation and significantly reduced transient enhanced diffusion. The effect is achieved by positioning the as-implanted amorphous/ crystalline interface close to the buried oxide interface to minimize interstitials while leaving a single-crystal seed to support solid-phase epitaxy. Results support the idea that the interface between the Si overlayer and the buried oxide is an efficient interstitial sink. © 2007 American Institute of Physics. ͓DOI: 10.1063/1.2778749͔Highly activated ultrashallow boxlike doping profiles are an important requirement for advanced planar complementary metal oxide semiconductor ͑MOS͒ applications. 1 A promising fabrication approach for p-channel MOS transistors is the use of Ge preamorphizing implants ͑PAIs͒ prior to ultralow energy B implantation. This reduces channeling and increases electrical activation due to solid-phase epitaxial regrowth ͑SPER͒. 2 For future technology nodes, bulk Si wafers may be replaced by silicon on insulator ͑SOI͒. 3 Unfortunately, in both bulk Si and SOI, the PAI implantation step causes an interstitial-rich "end-of-range" ͑EOR͒ defect band to form on further annealing. As this EOR band evolves, it releases self-interstitials, causing transient enhanced diffusion ͑TED͒ and boron-interstitial cluster ͑BIC͒ formation which manifests itself as electrical deactivation. 4 In SOI, a proportion of the emitted self-interstitials may migrate to nearby sinks such as the silicon/buried oxide ͑BOX͒ interface, thus reducing the amount of B deactivation that occurs. 5 This letter quantifies the role of the BOX and shows the dramatic advantages-in terms of reduced diffusion and deactivation-that can be achieved by exploiting the positioning of the EOR defect band within the silicon top layer in SOI. We will show that two distinct physical processes are involved: the removal of interstitials at the BOX interface following diffusion within the Si overlayer and the cutting off of the "as-implanted" excess interstitial profile within the BOX.Experiments were performed on n-type ͗100͘ Czochralski Si wafers with a resistivity of ϳ10-25 ⍀ cm, and on SOITEC© SOI wafers with a nominal 145 nm BOX and a 55 nm p-type Si overlayer. The wafers were implanted with Ge + at 8, 20, 24, 28, 32, or 36 keV to a dose of 1 ϫ 10 15 cm −2 , amorphizing to depths of ϳ20, 40, 45, 50, 55, and 60 nm, respectively, as determined by Rutherford backscattering spectrometry ͑RBS͒ and cross-sectional transmission electron microscopy ͑XTEM͒. Boron was subsequently implanted at 500 eV to a dose of 2 ϫ 10 15 cm −2 at 0°tilt and 0°twist. RBS used a 1.5 MeV He beam at 45°to the sample. 6 After implantation, samples received isochronal rapid thermal annealings in N 2 ambient, using a Process Products Corporation 18-lamp system ͑with lamps above and below the sample͒ operating with a set time of 60 s at temperatures in the range of 700-1000°C, considere...

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“…From the defect region, the supersaturation S = C i /C i ⁄ in equilibrium with the defect population linearly decreases to reach 0 at the fictitious distance L (recombination length) from the surface [20]. This necessary pinning of the supersaturation at the surface creates a concentration gradient and thus a flux of Is leaving the defect region.…”

Section: Defect Energeticsmentioning

confidence: 99%

On the origin of dislocation loops in irradiated materials: A point of view from silicon

Claverie

Cherkashin

2016

Nuclear Instruments and Methods in Physics Research Section B:

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Transient enhanced diffusion in preamorphized silicon: the role of the surface

Cited by 55 publications

References 15 publications

Surface proximity and boron concentration effects on end-of-range defect formation during nonmelt laser annealing

Surface proximity and boron concentration effects on end-of-range defect formation during nonmelt laser annealing

Boron deactivation in preamorphized silicon on insulator: Efficiency of the buried oxide as an interstitial sink

On the origin of dislocation loops in irradiated materials: A point of view from silicon

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