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

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.

1993 ◽  
Vol 303 ◽  
Author(s):  
Tzu-Hsin Huang ◽  
H. Kinoshita ◽  
D. L. Kwong

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.


1993 ◽  
Vol 303 ◽  
Author(s):  
H. Kinoshita ◽  
T. H. Huang ◽  
D. L. Kwong ◽  
P. E. Bakeman

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.


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

1999 ◽  
Vol 568 ◽  
Author(s):  
Aditya Agarwal ◽  
Hans-J. Gossmann ◽  
Anthony T. Fiory

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.


1993 ◽  
Vol 303 ◽  
Author(s):  
Bojun Zhang ◽  
Dennis M. Maher ◽  
Mark S. Denker ◽  
Mark A. Ray

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.


1998 ◽  
Vol 37 (Part 1, No. 3B) ◽  
pp. 1054-1058 ◽  
Author(s):  
Yukio Nishida ◽  
Hirokazu Sayama ◽  
Satoshi Shimizu ◽  
Takashi Kuroi ◽  
Akihiko Furukawa ◽  
...  

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