Effect of Fluorine on the Dopant Diffusion of Through-Oxtoe Implanted Boron in Si - a Correlation with Microstructural Defects

1992 ◽  
Vol 262 ◽  
Author(s):  
J. G. Huang ◽  
A. Lam ◽  
R. J. Jaccodine
Keyword(s):  
Strain Gradient ◽  
Dopant Diffusion ◽  
Boron Diffusion ◽  
Spreading Resistance ◽  
Oxygen Precipitation ◽  
Microstructural Defects ◽  
Oxygen Atoms

ABSTRACTIn case of boron through-oxide implant, it has been shown that the knocked-in oxygen atoms segregate at initially nucleated dislocation sites during the incubation and no significant junction movement is detected. The trapping of oxygen proceeds up to a certain time at which oxygen-precipitation occurs and this leads to an ejection of excess Si interstitials and further enhancing boron diffusion. However, with fluorine addition we believe that fluorine incorporation in SiO2 and/or SiO2/Si interface not only releases the strain gradient but also suppresses the silicon interstitials ejection and by this means suppresses the oxidation-enhanced boron diffusion. Correlated results of TEM microdefect structures and spreading resistance profiles are used to further support our postulation.

The Electrical and Optical Properties of Point and Extended Defects in Silicon Arising from Oxygen Precipitation

2007 ◽  
Vol 131-133 ◽  
pp. 225-232 ◽  
Author(s):  
R. Jones
Keyword(s):  
Optical Properties ◽  
Electrical Properties ◽  
Electrical Activity ◽  
Theoretical Work ◽  
Precipitation Process ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Electrical And Optical Properties ◽  
Oxygen Precipitation ◽  
Oxygen Atoms

Oxygen precipitation in Si is a complex set of processes which has been studied over many years. Here we review theoretical work relating to the precipitation process. At temperatures around 450°C oxygen atoms become mobile and form a family of thermal double donors. The structure of these defects and the origin of their electrical activity is discussed. At temperature around 650°C these donors disappear and there is a growth of SiO2 precipitates along with rod like defects which are extended defects involving Si interstitials. At higher temperatures these collapse into dislocation loops. The structure and electrical properties of the rod like defect are described and compared with those of dislocations.

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.

Strengths and Limitations of the Vacancy Engineering Approach for the Control of Dopant Diffusion and Activation in Silicon

2008 ◽  
Vol 1070 ◽  
Author(s):  
Alain Claverie ◽  
Fuccio Cristiano ◽  
Mathieu Gavelle ◽  
Fabrice Sévérac ◽  
Frédéric Cayrel ◽  
...  
Keyword(s):  
Ostwald Ripening ◽  
Solubility Limit ◽  
High Energy ◽  
Dopant Diffusion ◽  
Boron Diffusion ◽  
Significant Control ◽  
Alternative Approach ◽  
Silicon Excess ◽  
Ultra Shallow Junctions ◽  
Activation Annealing

ABSTRACTThe fabrication of highly doped and ultra-shallow junctions in silicon is a very challenging problem for the materials scientist. The activation levels which are targeted are well beyond the solubility limit of current dopants in Si and, ideally, they should not diffuse during the activation annealing. In practice, the situation is even worse and when boron is implanted into silicon excess Si interstitial atoms are generated which enhance boron diffusion and favor the formation of Boron-Silicon Interstitials Clusters (BICs). An elegant approach to overcome these difficulties is to enrich the Si layers where boron will be implanted with vacancies before or during the activation annealing. Spectacular results have been recently brought to the community showing both a significant control over dopant diffusion and an increased activation of boron in such layers. In general, the enrichment of the Si layers with vacancies is obtained by Si+ implantation at high energy. We have recently developed an alternative approach in which the vacancies are injected from populations of empty voids undergoing Ostwald ripening during annealing. While different, the effects are also spectacular. The goal of this work is to establish a fair evaluation of these different approaches under technologically relevant conditions. The application domains of both techniques are discussed and future directions for their development/improvement are indicated.

Modelinig of Dopant Diffusion and Associated Effects in Silicon

1982 ◽  
Vol 14 ◽  
Author(s):  
Richard B. Fair
Keyword(s):  
Point Defects ◽  
Stacking Fault ◽  
Relative Importance ◽  
Dopant Diffusion ◽  
Oxygen Precipitation ◽  
Fault Growth

ABSTRACTResearch in the area of dopant diffusion in Si has focused on identifying the specific mechanisms and point defects involved. Recent approaches include observing the effects of diffusion and doping on oxygen precipitation, stacking fault growth or shrinkage, enhanced/retarded diffusion of one dopant in the presence of another. Very few of these studies have yielded unambiguous interpretations as a result of the indirect nature of the experiments. However, taken together we can infer the relative importance of vacancies versus Si selfinterstitials in the diffusion of each dopant species.

Effect of Recoil Implantation of Oxygen on Boron Enhanced Diffusion in Silicon

1989 ◽  
Vol 147 ◽  
Author(s):  
D. Fan ◽  
R. J. Jaccodine
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Silicon Dioxide ◽  
Device Fabrication ◽  
Boron Diffusion ◽  
Spreading Resistance ◽  
Recoil Implantation ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Transmission Electron

In device fabrication, dopants are frequently implanted into silicon through silicon dioxide masks. A consequence of this technique is the co-implantation of recoiled oxygen into the substrate. This study investigates the effect of recoiled oxygen on the widely observed transient enhanced boron diffusion. Comparison of the spreading resistance profiles of annealed through-oxide and directly implanted samples reveals that transient enhanced diffusion of boron can be suppressed by the former process. Continued annealing of the through-oxide implanted silicon recovers the enhanced diffusion of boron. This behavior is believed to be due to precipitation of recoiled oxygen. The mechanisms leading to the above observations are discussed and transmission electron microscopy support presented.

Diffusion and Electroluminescence Studies of Low Temperature Diffusion of Boron in 3C-SiC

2008 ◽  
Vol 600-603 ◽  
pp. 457-460 ◽  
Author(s):  
I.G. Atabaev ◽  
Chin Che Tin ◽  
B.G. Atabaev ◽  
T.M. Saliev ◽  
E.N. Bakhranov ◽  
...  
Keyword(s):  
Activation Energy ◽  
Low Temperature ◽  
Boron Diffusion ◽  
Spreading Resistance ◽  
Temperature Range ◽  
Growth Defects ◽  
Temperature Diffusion

The characteristics of boron diffusion in 3C-SiC at low temperature have been measured using spreading resistance technique and electroluminescence spectroscopy. The coefficient of boron diffusion in the temperature range of 1150 –1250°С has been found to be about 5.5 x 10-11–5.0 x 10-10 cm2/sec and the activation energy of boron diffusion was determined to be about 0.9 –1.15 eV. Electroluminescence spectra of 3C-SiC p-n junction structures showed peaks at 750 and 630 nm due to growth defects and carbon-silicon divacancies respectively.

Study of Oxygen Diffusion and Clustering in Silicon Using an Empirical Interatomic Potential

1995 ◽  
Vol 378 ◽  
Author(s):  
Z. Jiang ◽  
R. A. Brown
Keyword(s):  
Interatomic Potential ◽  
Crystalline Silicon ◽  
Diffusion Path ◽  
Rate Theory ◽  
Free Energies ◽  
Silicon Crystals ◽  
Oxygen Precipitation ◽  
Dynamics Simulations ◽  
Small Clusters ◽  
Oxygen Atoms

AbstractThe diffusion path and diffusivity of oxygen in crystalline silicon are computed using an empirical interatomic potential which was recently developed [1] for modelling the interactions between oxygen and silicon atoms. The diffusion path is determined by constrained energy minimization, and the diffusivity is computed using jump rate theory. The calculated diffusivity D=0.025 exp(-2.43eV/kBT) cm2/sec is in excellent agreement with experimental data. The same interatomic potential also is used to study the formation of small clusters of oxygen atoms in silicon. The structures of these clusters are found by NPT molecular dynamics simulations, and their free energies are calculated by thermodynamic integration. These free energies are used to predict the temperature dependence of the equilibrium partitioning of oxygen atoms into clusters of different sizes. The calculations show that, for given total oxygen concentration, most oxygen atoms are in clusters at temperature below 1300K, and that the average cluster size increases with decreasing temperature. These results are in qualitative agreement with the effects of thermal annealing on oxygen precipitation in silicon crystals.

scholarly journals Quantitative scanning spreading resistance microscopy on n-type dopant diffusion profiles in germanium and the origin of dopant deactivation

2019 ◽  
Vol 125 (8) ◽  
pp. 085105 ◽  
Author(s):  
Jan K. Prüßing ◽  
Gerry Hamdana ◽  
Dominique Bougeard ◽  
Erwin Peiner ◽  
Hartmut Bracht
Keyword(s):  
Dopant Diffusion ◽  
Spreading Resistance ◽  
Diffusion Profiles ◽  
Dopant Deactivation

Effect of Ion Bombardment on the Dopant Diffusion During Reactive Ion Etching (RIE) of Dielectric Films Deposited on Silicon

1988 ◽  
Vol 128 ◽  
Author(s):  
K. Shenai ◽  
N. Lewis ◽  
C. A. Smith ◽  
B. J. Baliga
Keyword(s):  
Plasma Etching ◽  
Silicon Surface ◽  
Reactive Ion Etching ◽  
Oxide Films ◽  
Silicon Surfaces ◽  
Dopant Diffusion ◽  
Boron Diffusion ◽  
Ion Etching ◽  
Etched Silicon ◽  
Doping Profiles

ABSTRACTWe report on the results obtained from a study conducted to understand the effect of reactive ion etching (RIE) of oxide films on the dopant diffusion in ion-implanted silicon. Thermally grown oxide films on silicon were plasma etched in a CHF3/CO2 plasma. The residual silicon surface damage created during plasma etching was removed by employing a low ion-bombardment, two-step surface plasma cleaning process. The samples with oxide films etched in a wet chemical etchant provided the control for evaluating the effect of the RIE process. The samples were implanted with boron and boron was activated under various conditions to form p-n junctions to obtain a range of boron doping profiles and junction depths. Some boron doped samples were implanted with arsenic to form a heavily doped n+ region at the silicon surface. The resulting doping profiles were analysed using spreading resistance profiling (SRP), four-point probe measurements, and secondary ion-mass spectrometry (SIMS) to understand the activation, diffusion, and precipitation of various dopants. Detailed transmission electron microscopy (TEM) analysis was used to study the microstructural effects. It was observed that plasma etching of the oxide films prior to the formation of boron diffused surface regions in silicon resulted in significant changes in boron diffusion. For low boron implant doses, plasma etched silicon surfaces resulted in retarded boron diffusion. For high boron implant doses, plasma etched silicon surfaces lead to enhanced boron diffusion.

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