Damage-to-dose ratio after low energy silicon ion implantation into crystalline silicon

Y. Levin; N. Herbots; S. Dunham

doi:10.1557/jmr.1993.2305

Damage-to-dose ratio after low energy silicon ion implantation into crystalline silicon

Journal of Materials Research ◽

10.1557/jmr.1993.2305 ◽

1993 ◽

Vol 8 (9) ◽

pp. 2305-2309 ◽

Cited By ~ 1

Author(s):

Y. Levin ◽

N. Herbots ◽

S. Dunham

Keyword(s):

Ion Implantation ◽

Crystalline Silicon ◽

Crystal Surface ◽

Effective Diffusivity ◽

Low Energy ◽

Parallel Computer ◽

Analytic Approximation ◽

Dose Ratio ◽

Experimental Conditions ◽

Diffusion Of Vacancies

In this work, we develop a model describing the diffusion of vacancies and self-interstitials and their recombination during ion implantation. The model includes the effect of the moving surface due to regrowth and the defect generation rate as a function of depth based on Monte Carlo simulations. The results are compared to experimental measurements of the damage-to-dose ratio (DDR) after low energy, 40 eV, silicon ion implantation into silicon at 300 and 685 K. We have derived an analytic approximation which agrees with the results of the computational model, implemented on a CM-2 parallel computer. We find that the calculated effective diffusivity, the main adjustable parameter in the simulations, is much lower than predicted based on extrapolation from experiments at higher temperatures. We attribute this difference to the aggregation of self-interstitials. We also find that the effect of interstitial-vacancy recombination on DDR is negligible under the experimental conditions considered; however, the crystal surface motion has a significant impact on the results.

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Application of molecular dynamics for low-energy ion implantation in crystalline silicon

Journal of Vacuum Science & Technology B Microelectronics and Nanometer Structures Processing Measurement and Phenomena ◽

10.1116/1.2137333 ◽

2006 ◽

Vol 24 (1) ◽

pp. 462 ◽

Cited By ~ 1

Author(s):

H. Y. Chan ◽

M. P. Srinivasan ◽

N. J. Montgomery ◽

C. P. A. Mulcahy ◽

S. Biswas ◽

...

Keyword(s):

Molecular Dynamics ◽

Ion Implantation ◽

Crystalline Silicon ◽

Low Energy

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A Comparison of Low Energy BF2 Implantation in Si and Ge Preamorphized Silicon

MRS Proceedings ◽

10.1557/proc-128-611 ◽

1988 ◽

Vol 128 ◽

Cited By ~ 7

Author(s):

Gary A. Ruggles ◽

Shin-Nam Hong ◽

Jimmie J. Wortman ◽

Mehmet Ozturk ◽

Edward R. Myers ◽

...

Keyword(s):

Ion Implantation ◽

Crystalline Silicon ◽

Amorphous Layer ◽

Low Energy ◽

Electrical Activation ◽

Silicon Substrates ◽

Boron Diffusion ◽

Junction Depth ◽

Rapid Thermal Anneal ◽

Boron Segregation

ABSTRACTLow energy (6 keV) BF2 implantation was carried out using single crystal, Ge-preamorphized, and Si-preamorphized silicon substrates. Implanted substrates were rapid thermal annealed at temperatures from 600°C to 1050'C and boron channeling, diffusion, and activation were studied. Ge and Si preamorphization energies were chosen to produce nearly identical amorphous layer depths as determined by TEM micrographs (approximately 40 nm in both cases). Boron segregation to the end-of-range damage region was observed for 6 keV BF2 implantation into crystalline silicon, although none was detected in preamorphized substrates. Junction depths as shallow as 50 nm were obtained. In this ultra-low energy regime for ion implantation, boron diffusion was found to be as important as boron channeling in determining the junction depth, and thus, preamorphization does not result in a significant reduction in junction depth. However, the formation of junctions shallower than 100 rmu appears to require RTA temperatures below 1000°C which can lead to incomplete activation unless the substrate has been preamorphized. In the case of preamorphized samples, Hall measurements revealed that nearly complete electrical activation can be obtained for preamorphized samples after a 10 second rapid thermal anneal at temperatures as low as 600°C.

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Damage to Crystalline Silicon Following Implantation by Low Energy Silicon Ions

MRS Proceedings ◽

10.1557/proc-262-1037 ◽

1992 ◽

Vol 262 ◽

Author(s):

Y. Levine ◽

N. Herbots ◽

S. Dunham

Keyword(s):

Deposition Time ◽

Defect Formation ◽

Crystalline Silicon ◽

Focal Point ◽

Low Energy ◽

Dose Ratio ◽

New Approach ◽

Silicon Ions ◽

Constant Source ◽

Interaction Surface

ABSTRACTA new approach to investigate low energy defect formation and annealing in a crystal is developed, based on experimental observations of the total number of interstitials. The model is applied to damage in crystalline silicon caused by low energy implantation of Si-atoms during 40eV implants at 300°Kand 685°K. The model has two versions, analytical and computational, and includes two kinds of diffusing species, self-interstitials and vacancies, their interaction, surface motion of the growing crystal, and a constant source of defects. The source was calculated using a modified TRIM code (TRJMCSR). The focal point of the analysis is the number of interstitials per ion dose surviving at the end of the deposition time (damage to dose ratio or DDR, which is found to be an informative quantity and can be calculated for more sophisticated models including precipitation.

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Low-energy ion implantation for shallow junction crystalline silicon solar cell

Solar Energy ◽

10.1016/j.solener.2016.01.059 ◽

2016 ◽

Vol 130 ◽

pp. 25-32 ◽

Cited By ~ 7

Author(s):

Wei-Lin Yang ◽

Tai-Ying Lin ◽

Shu-Sheng Lien ◽

Likarn Wang

Keyword(s):

Solar Cell ◽

Ion Implantation ◽

Silicon Solar Cell ◽

Crystalline Silicon ◽

Low Energy ◽

Crystalline Silicon Solar Cell ◽

Shallow Junction

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Study of BF2 ion implantation into crystalline silicon : Influence of fluorine on boron diffusion

MRS Proceedings ◽

10.1557/proc-810-c8.9 ◽

2004 ◽

Vol 810 ◽

Cited By ~ 1

Author(s):

Lilya Ihaddadene-Lecoq ◽

Jerome Marcon ◽

Kaouther Ketata

Keyword(s):

Mass Spectrometry ◽

Ion Implantation ◽

Secondary Ion Mass Spectrometry ◽

Crystalline Silicon ◽

Low Energy ◽

Concentration Profiles ◽

Boron Diffusion ◽

Boron Difluoride ◽

Secondary Ion ◽

Trap Interstitial

ABSTRACTWe have investigated and modeled the diffusion of boron implanted into crystalline silicon in the form of boron difluoride BF2+. Low energy BF2+ 1×1015 cm−2 implantations at 2.0keV were characterized using Secondary Ion Mass Spectrometry (SIMS) in order to measure dopant profiles. RTA was carried out at 950°C, 1000°C, 1050°C and 1100°C during 10s, 20s, 30s and 60s. The results show that concentration profiles for BF2+ implant are shallower than those for a direct B+ ion implantation. This could be attributed to the presence of fluorine which trap interstitial Si so that interstitial silicon supersaturation is low near the surface.

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GaAs/AlGaAs Quantum Well Mixing Using Low Energy Ion Implantation and Rapid Thermal Annealing

MRS Proceedings ◽

10.1557/proc-144-445 ◽

1988 ◽

Vol 144 ◽

Cited By ~ 1

Author(s):

B. Elman ◽

Emil S. Koteles ◽

P. Melman ◽

C. A. Armiento

Keyword(s):

Ion Implantation ◽

Quantum Wells ◽

Thermal Annealing ◽

Rapid Thermal Annealing ◽

Ion Beam ◽

Low Energy ◽

Exciton Transition ◽

Transition Energies ◽

Diffusion Of Vacancies ◽

Implantation Fluence

ABSTRACTLow energy ion implantation followed by rapid thermal annealing (RTA) was utilized to modify exciton transition energies of MBE- rown GaAs/AlGaAs quantum wells (QW). The samples were irradiated with an 75As ion beam with an energy low enough that the depth of the disordered region was spatially separated from the QWs. After RTA, exciton energies (determined using optical spectroscopy) showed large increases which were dependent on QW widths and the implantation fluence with no significant increases in peak linewidths. These energy shifts were interpreted as resulting from the modification of the shapes of the as-grown QWs from square (abrupt interfaces) to rounded due to enhanced Ga and Al interdiffusion in irradiated areas. These results are similar to our data on the RTA of the same structures capped with SiO2 and are consistent with the model of enhanced intermixing of Al and Ga atoms due to diffusion of vacancies generated near the surface.

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Low-Energy Electron Damage to Condensed-Phase DNA and Its Constituents

International Journal of Molecular Sciences ◽

10.3390/ijms22157879 ◽

2021 ◽

Vol 22 (15) ◽

pp. 7879

Author(s):

Yingxia Gao ◽

Yi Zheng ◽

Léon Sanche

Keyword(s):

Condensed Phase ◽

Genetic Material ◽

High Energy ◽

Dna Lesions ◽

Low Energy ◽

Experimental Investigations ◽

Experimental Conditions ◽

Strand Breaks ◽

Sequence Of Events ◽

Wide Range

The complex physical and chemical reactions between the large number of low-energy (0–30 eV) electrons (LEEs) released by high energy radiation interacting with genetic material can lead to the formation of various DNA lesions such as crosslinks, single strand breaks, base modifications, and cleavage, as well as double strand breaks and other cluster damages. When crosslinks and cluster damages cannot be repaired by the cell, they can cause genetic loss of information, mutations, apoptosis, and promote genomic instability. Through the efforts of many research groups in the past two decades, the study of the interaction between LEEs and DNA under different experimental conditions has unveiled some of the main mechanisms responsible for these damages. In the present review, we focus on experimental investigations in the condensed phase that range from fundamental DNA constituents to oligonucleotides, synthetic duplex DNA, and bacterial (i.e., plasmid) DNA. These targets were irradiated either with LEEs from a monoenergetic-electron or photoelectron source, as sub-monolayer, monolayer, or multilayer films and within clusters or water solutions. Each type of experiment is briefly described, and the observed DNA damages are reported, along with the proposed mechanisms. Defining the role of LEEs within the sequence of events leading to radiobiological lesions contributes to our understanding of the action of radiation on living organisms, over a wide range of initial radiation energies. Applications of the interaction of LEEs with DNA to radiotherapy are briefly summarized.

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