Doping of Silicon by Ion Implantation

Concentration profiles of 20 keV ion implanted antimony into silicon single crystals are measured by radioactivation analysis and the enhanced diffusion of antimony is observed. The concentration profiles and the diffusion coefficient of antimony are found to be independent of temperature over the range between 500 and 800°C during ion implantation. The enhancement of diffusion during annealing after room temperature ion implantation is the same as that during high temperature ion implantation. The diffusion coefficient is estimated to be 1.1 x cm*/sec for diffusion during high temperature ion implantation and that during annealing after room temperature ion implantation. The measured concentration profiles agree very well with the calculated concentration profiles. These results are explained on the basis of a vacancy mechanism.

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“…The solid curve shown in Figures 3 to 6 is the result of the calculation of Eq. (7). The same values those used in the calculation of Eq.…”

Section: D(t -T')mentioning

confidence: 91%

“…(2) and (3) and is (7) where T is a duration of ion implantation. The solid curve shown in Figures 3 to 6 is the result of the calculation of Eq.…”

Section: D(t -T')mentioning

confidence: 99%

Enhanced diffusion in ion implanted silicon

et al. 1970

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“…Since there was no further injection of aluminum by PAD after RTA, these observations suggest that both the number of electrically active dopants, and the diffusion range of the Al dopants in the silicon increased with increasing RTA process temperature. These observations suggest that (i) CPD is a reasonable metric for monitoring the electrical response of the sub-surface doping, (ii) some thermal treatment was needed to thermally activate the dopants, and lower the energy level at the Si surface due to an increased concentration of holes, 46 and (iii) the implanted Al dopants out-diffused from the point of introduction with the thermal anneal.…”

Section: Journal Of Applied Physicsmentioning

confidence: 99%

Probe assisted localized doping of aluminum into silicon substrates

Ahn

Solares

You

et al. 2019

Journal of Applied Physics

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Precise control of dopant placement is crucial for the reproducible, and reliable, nanoscale semiconductor device fabrication. In this paper, we demonstrate an atomic force microscopy (AFM) probe assisted localized doping of aluminum into an n-type silicon (100) wafer to generate nanoscale counter-doped junctions within two nanometers of the silicon-air interface. The local doping results in changes in electrostatic potential, which are reported as contact potential difference, with nanoscale spatial resolution. In contrast to the literature where nano-mechanical defects in, or contaminants on, silicon substrates can result in measurable changes in the chemical potential of the near-surface, additional thermal treatment was needed to electrically activate the aluminum dopants in our current work. Unfortunately, the thermal activation step also caused the dopants to diffuse and geometric distortions in the doped area, i.e., broadening and blurring of the electrically distinct areas. The results from optimization efforts show that the "active" dopant concentration depended primarily on the thermal anneal temperature; additional AFM-tip dwell time during the aluminum implantation step had no meaningful impact on the electrical activity of the doped sites.

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“…XT has been studied extensively using various experimental and theoretical methods because of its intriguing solvatochromic behavior and its diverse applications like photopolymerization. [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Particularly, the photophysics and photochemistry of XT are sensitive to the hydrogen-bonding properties of the solvent. [10][11][12] XT in water showed two orders of magnitude higher fluorescence quantum yield relative to aprotic solvents.…”

Section: Introductionmentioning

confidence: 99%

Solvent effects on the structure of the triplet excited state of xanthone: a time-resolved resonance Raman study

Venkatraman

Umapathy

2016

J. Raman Spectrosc.

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Solvent effects, especially intermolecular hydrogen bonding, play a central role in the photophysics and photochemistry of aromatic ketones. To gain insight into the solute–solvent interactions and their implications for structure and reactivity, we studied xanthone (XT) in two different solvents of similar dipolarity: acetonitrile (ACN; aprotic) and methanol (MeOH; protic), using time‐resolved resonance Raman (TR3) spectroscopy in conjunction with time‐dependent density functional theory calculations. Raman excitation profiles of XT in ACN followed the triplet‐triplet absorption band with a shoulder at the blue end, but for MeOH, they followed the triplet‐triplet absorption band quite closely; therefore, we propose that the resonance enhancement of Raman peaks are from two states in ACN and from a single state in the MeOH solvent. Furthermore, a resonance Raman peak at 614 cm−1 (a2 symmetry) that appeared in ACN but not in the MeOH solvent has been identified as a vibronic active mode that could be involved in coupling the two lowest 13ππ* (13A1) and 13nπ* (13A2) excited states. This was further confirmed by depolarization ratio measurements of some of the representative TR3 peaks in ACN, which showed a depolarized intensity for the 614 cm−1 peak while the other peaks were polarized. Interestingly, we also observed blue shifting of some of the vibrational frequencies of XT in the 13ππ* state compared with the ground state with increasing solvent polarity. This anomalous blue shift casts doubt on the general use of the resonance canonical structure to explain the structure of the excited states. In summary, we propose that the different hydrogen bonding mechanisms exhibited by the two lowest triplet states of XT separate them further in energy and that this can contribute to its low reactivity towards H atom abstraction in protic solvents. Copyright © 2016 John Wiley & Sons, Ltd.

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Doping of Silicon by Ion Implantation

Cited by 36 publications

References 3 publications

Enhanced diffusion in ion implanted silicon

Enhanced diffusion in ion implanted silicon

Probe assisted localized doping of aluminum into silicon substrates

Solvent effects on the structure of the triplet excited state of xanthone: a time-resolved resonance Raman study

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