Semi-Empirical Model for Boron Diffusion During Rapid Thermal Annealing of BF2 Implanted Silicon

1993 ◽  
Vol 303 ◽  
Author(s):  
Tzu-Hsin Huang ◽  
H. Kinoshita ◽  
D. L. Kwong
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Enhanced Diffusion ◽  
Defect Clusters ◽  
Annealing Conditions ◽  
Wide Range ◽  
Point Defect Clusters ◽  
Semi Empirical

ABSTRACTThe mechanism of the enhanced diffusion of boron during rapid thermal annealing (RTA) of BF2-implanted Si has been investigated, and a diffusion model is accordingly developed for a wide range of implant and annealing conditions. Simulation results are in excellent agreement with experiments for BF2 implant doses from 2×1013 to 5×1015cm−2, implant energies from 6 to 45 keV, and annealing temperatures from 950 to 1100°C. This model not only accounts for the transient enhanced diffusion due to the annealing of point-defect clusters and dislocation loops, but also for the retarded diffusion due to dopant precipitation. All the parameters used in this model are analytically determined.

Modeling of Boron Diffusion and Activation for Nonequilibrium Rapid Thermal Annealing Application

1993 ◽  
Vol 303 ◽  
Author(s):  
H. Kinoshita ◽  
T. H. Huang ◽  
D. L. Kwong
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
High Dose ◽  
Boron Diffusion ◽  
Defect Model ◽  
Extended Defect ◽  
Enhanced Diffusion ◽  
Wide Range ◽  
Simulation Results ◽  
Single Set

ABSTRACTThe diffusion and activation of ion implanted boron and BF2 during rapid thermal annealing (RTA) was modeled by considering the reaction kinetics between point defects and boron. The diffusion model uses the Monte Carlo generated point defect profiles, an extended defect model and a surface amorphization model for high dose BF2 implantation. Excellent simulation results have been achieved by using a single set of diffusion and kinetic parameters to model the enhanced diffusion of boron during RTA for a wide range of B and BF2 implant doses.

Onset of Extended Defect Formation and Enhanced Diffusion for Ultra-Low Energy Boron Implants

1999 ◽  
Vol 568 ◽  
Author(s):  
Jinning Liu ◽  
Kevin S. Jones ◽  
Daniel F. Downey ◽  
Sandeep Mehta
Keyword(s):  
Defect Formation ◽  
Low Energy ◽  
Dislocation Loops ◽  
Boron Diffusion ◽  
Extended Defect ◽  
Enhanced Diffusion ◽  
Annealing Conditions ◽  
Diffusion Enhancement ◽  
Spike Anneal ◽  
Low Thermal Budget

ABSTRACTTo meet the challenge of achieving ultra shallow p+/n source/drain extension junctions for 0.1 Oim node devices, ultra low energy boron implant and advanced annealing techniques have been explored. In this paper, we report the extended defect and boron diffusion behavior with various implant and annealing conditions. Boron implants were performed at energies from 0.25keV to lkeV and doses of 5 × 1014 cm−2 and 1 × 1015cm−2. Subsequent anneals were carried out in nitrogen ambient. The effect of energy, dose and oxide capping on extended defect formation and enhanced dopant diffusion was examined. It was observed that a thin screen oxide layer (35Å), grown prior to implantation, reduces the concentration of dopant in the Si by a significant amount as expected. This oxide also reduces the dislocation loops in the lattice and lowers diffusion enhancement of the dopant during annealing. The final junction depth can be optimized by using a low thermal budget spike anneal in a controlled oxygen ambient.

Germanium Implantation into Silicon: An Alternate Pre-Amorphization/Rapid Thermal Annealing Procedure for Shallow Junction Technology

1983 ◽  
Vol 23 ◽  
Author(s):  
D.K. Sadana ◽  
E. Myers ◽  
J. Liu ◽  
T. Finstad ◽  
G.A. Rozgonyi
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Surface Region ◽  
Amorphous Layer ◽  
High Dose ◽  
Dislocation Loops ◽  
Cross Sectional ◽  
Defect Clusters ◽  
Ion Damage ◽  
Free Material

ABSTRACTGermanium implantation into Si was conducted to pre-amorphize the-si surface layer prior to a shallow/high dose (42 keV, 2 × 1015 cm−2) BF2 implant. Cross-sectional transmission electron microscopy showed that rapid thermal annealing (RTA) of the amorphous layer (without BF2 ) leaves defect-free material in the implanted region. Only a discrete layer of small (∼300Å) dislocation loops due to straggling ion damage was found to be present at a depth corresponding to the amorphous/crystalline interface. RTA of the amorphous layer with the BF2 creatpd a high density of uniformly. distributed fine defect clusters (∼50Å) in the surface region (0–500Å) in addition to the straggling ion damage. Boron and F profiles obtained by secondary ion mass spectrometry from the unannealed and rapid thermally annealed samples showed the presence of high concentrations of these impurities in the surface region where the fine defect clusters were observed. A comparison of the RTA behavior of the pre-amorphized surface layers (with or without BF2 ) produced by Ge and self-implantation is presented.

scholarly journals Transient Enhanced Diffusion and Gettering of Dopants in Ion Implanted Silicon

1984 ◽  
Vol 36 ◽  
Author(s):  
S. J. Pennycook ◽  
J. Narayan ◽  
R. J. Culbertson
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Solid Phase ◽  
Subsequent Annealing ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Dopant Profile ◽  
Dopant Atoms ◽  
Ion Implanted

ABSTRACTWe have studied in detail the transient enhanced diffusion observed during furnace or rapid-thermal-annealing of ion-implanted Si. We show that the effect originates in the trapping of Si atoms by dopant atoms during implantation, which are retained during solid-phase-epitaxial (SPE) growth but released by subsequent annealing to cause a transient dopant precipitation or profile broadening. The interstitials condense to form a band of dislocation loops located at the peak of the dopant profile, which may be distinct from the band formed at the original amorphous/crystalline interface. The band can develop into a network and effectively getter the dopant. We discuss the conditions under which the various effects may or may not be observed, and discuss preliminary observations on As+ implanted Si.

Boron Diffusion in Fluorine Preamorphized Silicon During Rapid Thermal Annealing

1993 ◽  
Vol 303 ◽  
Author(s):  
H. Kinoshita ◽  
T. H. Huang ◽  
D. L. Kwong ◽  
P. E. Bakeman
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Annealed Sample ◽  
Transmission Electron Micrograph ◽  
Boron Diffusion ◽  
Cross Sectional ◽  
Dopant Activation ◽  
Enhanced Diffusion ◽  
Transmission Electron ◽  
Secondary Ion

ABSTRACTThe effect of fluorine preamorphization on boron diffusion and activation during rapid thermal annealing (RTA) has been investigated. Compared with low energy B or BF2 implant into crystalline Si, F preamorphization suppressed the transient enhanced diffusion of B and increased dopant activation. Results show that the tail diffusion was absent, and thus the junction depth of the RTA annealed sample was established by the as-implanted B profile. Secondary ion mass spectroscopy and cross-sectional transmission electron micrograph results show F accumulation near the surface and at end-of-range defects. The interaction of F with defects is believed to reduce the B diffusion during RTA.

Annealing Of Radiation Damage in Tungsten

1970 ◽  
Vol 28 ◽  
pp. 412-413
Author(s):  
Robert C. Rau ◽  
John Moteff
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Radiation Damage ◽  
Thermal Annealing ◽  
Neutron Fluence ◽  
Dislocation Loops ◽  
Defect Clusters ◽  
Polycrystalline Tungsten ◽  
Transmission Electron ◽  
Radiation Induced

Transmission electron microscopy has been used to study the thermal annealing of radiation induced defect clusters in polycrystalline tungsten. Specimens were taken from cylindrical tensile bars which had been irradiated to a fast (E > 1 MeV) neutron fluence of 4.2 × 1019 n/cm2 at 70°C, annealed for one hour at various temperatures in argon, and tensile tested at 240°C in helium. Foils from both the unstressed button heads and the reduced areas near the fracture were examined.Figure 1 shows typical microstructures in button head foils. In the unannealed condition, Fig. 1(a), a dispersion of fine dot clusters was present. Annealing at 435°C, Fig. 1(b), produced an apparent slight decrease in cluster concentration, but annealing at 740°C, Fig. 1(C), resulted in a noticeable densification of the clusters. Finally, annealing at 900°C and 1040°C, Figs. 1(d) and (e), caused a definite decrease in cluster concentration and led to the formation of resolvable dislocation loops.

Measurement and modeling of boron diffusion in Si and strained Si1−xGexepitaxial layers during rapid thermal annealing

1993 ◽  
Vol 74 (9) ◽  
pp. 5520-5526 ◽  
Author(s):  
G. H. Loechelt ◽  
G. Tam ◽  
J. W. Steele ◽  
L. K. Knoch ◽  
K. M. Klein ◽  
...  
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Boron Diffusion

Ultra-Shallow Junctions by Ion Implantation and Rapid Thermal Annealing: Spike-Anneals, Ramp Rate Effects

1999 ◽  
Vol 568 ◽  
Author(s):  
Aditya Agarwal ◽  
Hans-J. Gossmann ◽  
Anthony T. Fiory
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Driving Forces ◽  
Recent Experimental Data ◽  
Enhanced Diffusion ◽  
Temperature Ramp ◽  
Rate Effects ◽  
Low Energies ◽  
Ultra Shallow Junctions ◽  
P Type

ABSTRACTOver the last couple of years rapid thermal annealing (RTA) equipment suppliers have been aggressively developing lamp-based furnaces capable of achieving ramp-up rates on the order of hundreds of degrees per second. One of the driving forces for adopting such a strategy was the experimental demonstration of 30nm p-type junctions by employing a ramp-up rate of ≈400°C/s. It was subsequently proposed that the ultra-fast temperature ramp-up was suppressing transient enhanced diffusion (TED) of boron which results from the interaction of the implantation damage with the dopant. The capability to achieve very high temperature ramp-rates was thus embraced as an essential requirement of the next generation of RTA equipment.In this paper, recent experimental data examining the effect of the ramp-up rate during spike-and soak-anneals on enhanced diffusion and shallow junction formation is reviewed. The advantage of increasing the ramp-up rate is found to be largest for the shallowest, 0.5-keV, B implants. At such ultra-low energies (ULE) the advantage arises from a reduction of the total thermal budget. Simulations reveal that a point of diminishing return is quickly reached when increasing the ramp-up rate since the ramp-down rate is in practice limited. At energies where TED dominates, a high ramp-up rate is only effective in minimizing diffusion if the implanted dose is sufficiently small so that the TED can be run out during the ramp-up portion of the anneal; for larger doses, a high ramp-up rate only serves to postpone the TED to the ramp-down duration of the anneal. However, even when TED is minimized at higher implant energies via high ramp-up rates, the advantage is unobservable due to the rather large as-implanted depth. It appears then that while spike anneals allow the activation of ULE-implanted dopants to be maximized while minimizing their diffusion the limitation imposed by the ramp-down rate compromises the advantage of very aggressive ramp-up rates.

Correlation Between Defect Characteristics and Layer Intermixing in Si Implanted GaAs/AIGaAs Superlattices

1989 ◽  
Vol 147 ◽  
Author(s):  
Samuel Chen ◽  
S.-Tong Lee ◽  
G. Braunstein ◽  
G. Rajeswaran ◽  
P. Fellinger
Keyword(s):  
Ion Implantation ◽  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Peak Position ◽  
Compound Semiconductor ◽  
Subsequent Annealing ◽  
Semiconductor Superlattices ◽  
Furnace Annealing ◽  
Annealing Conditions ◽  
Induced Defects

AbstractDefects induced by ion implantation and subsequent annealing are found to either promote or suppress layer intermixing in Ill-V compound semiconductor superlattices (SLs). We have studied this intriguing relationship by examining how implantation and annealing conditions affect defect creation and their relevance to intermixing. Layer intermixing has been induced in SLs implanted with 220 keV Si+ at doses < 1 × 1014 ions/cm2 and annealed at 850°C for 3 hrs or 1050°C for 10 s. Upon furnace annealing, significant Si in-diffusion is observed over the entire intermixed region, but with rapid thermal annealing layer intermixing is accompanied by negligible Si movement. TEM showed that the totally intermixed layers are centered around a buried band of secondary defects and below the Si peak position. In the nearsurface region layer intermixing is suppressed and is only partially completed at ≤1 × 1015 Si/cm2. This inhibition is correlated to a loss of the mobile implantation-induced defects, which are responsible for intermixing.

Stability of Ultra-Thin Gate Oxides with Boron Doped Polysilicon Gate Structures After Rapid Thermal Annealing

1993 ◽  
Vol 303 ◽  
Author(s):  
Bojun Zhang ◽  
Dennis M. Maher ◽  
Mark S. Denker ◽  
Mark A. Ray
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Depth Profiling ◽  
Gate Oxide ◽  
Annealing Condition ◽  
Dopant Diffusion ◽  
Boron Diffusion ◽  
Gate Oxides ◽  
Diffusion Behavior ◽  
Polysilicon Gate

ABSTRACTWe report a systematic study of dopant diffusion behavior for thin gate oxides and polysilicon implanted gate structures. Boron behavior is emphasized and its behavior is compared to that of As+ and BF2+. Dopant activation is achieved by rapid thermal annealing. Test structures with 100 Å, 60 Å and 30 Å gate oxides and ion implanted polysilicon gate electrodes were fabricated and characterized after annealing by SIMS, SEM, TEM, and C-V rpeasurements. For arsenic implanted structures, no dopant diffusion through a gate oxide of 30 Å thickness and an annealing condition as high as 1 100*C/1Os was observed. For boron implanted structures, as indicated by SIMS depth profiling, structures annealed at 1000*C/10s exhibit a so-called critical condition for boron diffusion through a 30 Å gate oxide. Boron dopant penetration is clearly observed for 60 Å gate oxides at an annealing condition of 1050 0C/10s. The flatband voltage shift can be as high as 0.56 volts as indicated by C-V measurements for boron penetrated gate oxides. However, 100 Å gate oxides are good diffusion barriers for boron at an annealing condition of 1100°C/10s. For BF2 implanted structures, the diffusion behavior is consistent with behavior reported in the literature.

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