Effect of End-of-Range Defects, Arsenic Clustering and Precipitation on Transient Enhanced Diffusion in As+ Implanted Si

1997 ◽  
Vol 469 ◽  
Author(s):  
V. Krishnamoorthy ◽  
D. Venables ◽  
K. Moeller ◽  
K. S. Jones ◽  
J. Jackson
Keyword(s):  
Amorphous Layer ◽  
Silicon Wafers ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Transient Enhanced Diffusion ◽  
Defect Evolution ◽  
The Difference

ABSTRACT(001) CZ silicon wafers were implanted with As at lOOkeV to a dose of 1×1015/cm2. The implant was amorphizing in nature and the peak As concentration was below the As clustering threshold. Subsequently, a second As+or Ge+ implant at 30keV at doses of 2×1015/cm2, 5×1015/cm2 and 1×1016/cm2 were performed, respectively, into the as-implanted samples. The samples with a double arsenic implant induce As clustering at the lower doses and As precipitation at the highest dose at the projected range. However, the samples with the Ge do not induce clustering or precipitation. The samples were annealed at 700°C for various times to regrow the amorphous layer and to cause enhanced arsenic diffusion beyond the end-of range region. These samples wereanalyzed by SIMS and TEM. The difference in the defect evolution at the end-of-range region and TED beyond the end-of-range region between the As and Ge implanted samples was used to isolate the effects of As clustering and precipitation.

Junction Depth Reduction of ion Implanted Boron in Silicon Through Fluorine ion Implantation

2000 ◽  
Vol 610 ◽  
Author(s):  
L. S. Robertson ◽  
P. N. Warnes ◽  
K. S. Jones ◽  
S. K. Earles ◽  
M. E. Law ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Secondary Ion Mass Spectrometry ◽  
Chemical Species ◽  
Amorphous Layer ◽  
Experimental Conditions ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Transmission Electron ◽  
Species Effect ◽  
Boron Diffusivity

AbstractThe interaction between boron and excess silicon interstitials caused by ion implantation hinders the formation of ultra-shallow, low resistivity junctions. Previous studies have shown that fluorine reduces boron transient enhanced diffusion, however it is unclear whether this observed phenomenon is due to the fluorine interacting with the boron atoms or silicon self-interstitials. Amorphization of a n-type Czochralski wafer was achieved with a 70 keV Si+ implantation at a dose of 1×1015/cm2. The Si+ implant produced a 1500Å deep amorphous layer, which was then implanted with 1.12 keV 1×1015/cm2 B+. The samples were then implanted with a dose of 2×1015/cm2F+ at various energies ranging from 2 keV to 36 keV. Ellipsometry measurements showed no increase in the amorphous layer thickness from either the boron or fluorine implants. The experimental conditions allowed the chemical species effect to be studied independent of the implant damage caused by the fluorine implant. Post-implantation anneals were performed in a tube furnace at 750° C. Secondary ion mass spectrometry was used to monitor the dopant diffusion after annealing. Transmission electron microscopy (TEM) was used to study the end-of-range defect evolution. The addition of fluorine reduces the boron transient enhanced diffusion for all fluorine energies. It was observed that both the magnitude of the boron diffusivity and the concentration gradient of the boron profile vary as a function of fluorine energy.

Modeling of Dislocation Loop Growth and Transient Enhanced Diffusion in Silicon for Amorphizing Implants

1996 ◽  
Vol 438 ◽  
Author(s):  
Alp H. Gencer ◽  
Scott T. Dunham
Keyword(s):  
Dislocation Loop ◽  
Silicon Wafers ◽  
Comprehensive Model ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Formation And Evolution

It has been observed that dislocation loops form and grow during annealing of silicon wafers implanted at doses above the amorphization threshold. Dislocation loops can act to store interstitials for prolonged periods of anneals, sustaining an interstitial super-saturation and thus causing substantial transient enhanced diffusion (TED). We have developed a comprehensive model which, in combination with a model and parameters for s{311} defects from previous work, accounts for the formation and evolution of dislocation loops during ion implant annealing, as well as giving the correct TED behavior.

Complete Suppression of the Transient Enhanced Diffusion of B Implanted in Preamorphized Si by Interstitial Trapping in a Spatially Separated C-Rich Layer

2002 ◽  
Vol 717 ◽  
Author(s):  
E. Napolitani ◽  
A. Coati ◽  
D. De Salvador ◽  
A. Carnera ◽  
S. Mirabella ◽  
...  
Keyword(s):  
Silicon Layer ◽  
Complementary Metal Oxide Semiconductor ◽  
Amorphous Layer ◽  
Oxide Semiconductor ◽  
Complete Suppression ◽  
Silicon Sample ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Ultra Shallow Junctions ◽  
Technology Nodes

AbstractA method for completely suppressing the transient enhanced diffusion (TED) of boron implanted in preamorphized silicon is demonstrated. Boron is implanted in a molecular beam epitaxy (MBE) grown silicon sample that has been previously amorphized by silicon implantation. The sample is then annealed in order to epitaxially regrow the amorphous layer and electrically activate the dopant. The back-flow of silicon interstitials released by the preamorphization end-of-range (EOR) damage is completely trapped by a carbon-rich silicon layer interposed by MBE between the damage and the implanted boron. No appreciable TED is observed in the samples up to complete dissolution of the EOR damage, and complete electrical activation is obtained. The method might be considered for the realization of ultra shallow junctions for the far future complementary metal-oxide semiconductor technology nodes.

Fundamental Modeling of Transient Enhanced Diffusion through Extended Defect Evolution

1997 ◽  
Vol 469 ◽  
Author(s):  
A. H. Gencer ◽  
S. Chakravarthi ◽  
I. Clejan ◽  
S. T. Dunham
Keyword(s):  
Point Defect ◽  
Extended Defects ◽  
Dislocation Loops ◽  
Extended Defect ◽  
Enhanced Diffusion ◽  
Fundamental Model ◽  
Transient Enhanced Diffusion ◽  
Defect Evolution

Prediction of transient enhanced diffusion (TED) requires modeling of extended defects of many types, such as {311} defects, dislocation loops, boron-interstitial clusters, arsenic precipitates, etc. These extended defects not only form individually, but they also interact with each other through changes in point defect and solute concentrations. We have developed a fundamental model which can account for the behavior of a broad range of extended defects, as well as their interactions with each other. We have successfully applied and parameterized our model to a range of systems and conditions, some of which are presented in this paper.

Boron Implantation into Silicon Subject to Hydrogen Plasma

2000 ◽  
Vol 610 ◽  
Author(s):  
Sanjay Rangan ◽  
Mark Horn ◽  
S. Ashok
Keyword(s):  
Defect Density ◽  
Deep Level ◽  
Hydrogen Plasma ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Defect Evolution ◽  
Boron Implantation ◽  
Anneal Temperature

AbstractAlleviating transient enhanced diffusion (TED) is one among several issues that has to be solved to realize deep sub-micron CMOS. In this paper we present the influence of hydrogen plasma on TED of boron, along with deep level transient spectroscopic (DLTS) studies on defect evolution as a function of anneal temperature. The studies reveal that TED monotonically increases as a function of anneal temperature up to 650°C, where maximum TED occurs. Further increase in anneal temperature reveals TED reduction. The DLTS reveals a corresponding increase in defect density up to 650°C and then decreases when annealed at 850°C for the same amount of time.

Ion implantation of silicon wafers for defect-reduced doped layer formation with low dopant atom diffusion

1994 ◽  
Vol 9 (11) ◽  
pp. 2987-2992
Author(s):  
Naoto Shigenaka ◽  
Shigeki Ono ◽  
Tsuneyuki Hashimoto ◽  
Motomasa Fuse ◽  
Nobuo Owada
Keyword(s):  
Ion Implantation ◽  
Amorphous Phase ◽  
Amorphous Layer ◽  
Defect Layer ◽  
Silicon Wafers ◽  
Dopant Atom ◽  
Layer Formation ◽  
Atom Diffusion ◽  
Enhanced Diffusion ◽  
Dopant Atoms

A new process for ion implantation into silicon wafers was proposed. This process has an additional implantation step to form an amorphous phase. At first self-ions are implanted into a cooled wafer (< −30 °C) to form the amorphous phase, and subsequently dopant atoms are implanted to form a doped layer within the amorphous layer. After annealing above 650 °C, the silicon wafer is completely recrystallized, and no defects with sizes detectable by TEM are present near the doped layer. There is indeed a defect layer in the wafer; however, it lies along the amorphous/crystal interface that is behind the doped layer. The concentration profile of the dopant atoms is not changed during epitaxial recrystallization, and further dopant atom diffusion during annealing is limited to about 0.05 μm, because defect-enhanced diffusion does not occur. The double implantation method is considered to be effective for doped layer formation in the VLSI fabrication process.

Modeling of Dislocation Loop Growth and Transient Enhanced Diffusion in Silicon for Amorphizing Implants

1996 ◽  
Vol 439 ◽  
Author(s):  
Alp H. Gencer ◽  
Scott T. Dunham
Keyword(s):  
Dislocation Loop ◽  
Silicon Wafers ◽  
Comprehensive Model ◽  
Dislocation Loops ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Formation And Evolution

AbstractIt has been observed that dislocation loops form and grow during annealing of silicon wafers implanted at doses above the amorphization threshold. Dislocation loops can act to store interstitials for prolonged periods of anneals, sustaining an interstitial super-saturation and thus causing substantial transient enhanced diffusion (TED). We have developed a comprehensive model which, in combination with a model and parameters for {311} defects from previous work, accounts for the formation and evolution of dislocation loops during ion implant annealing, as well as giving the correct TED behavior.

Atomistic analysis of defect evolution and transient enhanced diffusion in silicon

2003 ◽  
Vol 94 (2) ◽  
pp. 1013-1018 ◽  
Author(s):  
Maria Aboy ◽  
Lourdes Pelaz ◽  
Luis A. Marqués ◽  
L. Enriquez ◽  
Juan Barbolla
Keyword(s):  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Defect Evolution

The Role of Vacancies and Interstitials in Transient Enhanced Diffusion of Arsenic Implanted into Silicon

1997 ◽  
Vol 469 ◽  
Author(s):  
D. Venables ◽  
V. Krishnamoorthy ◽  
H.- J. Gossmann ◽  
A. Lilak ◽  
K. S. Jones ◽  
...  
Keyword(s):  
Fermi Level ◽  
Point Defect ◽  
Boron Diffusion ◽  
Direct Role ◽  
Enhanced Diffusion ◽  
Projected Range ◽  
Transient Enhanced Diffusion ◽  
Diffusion Enhancement ◽  
Recombination Centers

ABSTRACTBoron and antimony doped superlattices (DSLs) were implanted with arsenic at 40 keV to doses of 2×1014 cm−2, 5×1015 cm−2 and 2×1016 cm−2. Increasing the arsenic dose above 5×1015 cm−2 resulted in a reduction in the extent of arsenic transient enhanced diffusion (TED) following annealing at 700°C, 16 hr. Concurrent with this reduction in TED was a reduction in the number of free interstitials beyond the end-of-range, as measured by the boron diffusion enhancement in the doped superlattices. No enhancement in antimony diffusivity was observed in this region, indicating that vacancies play no direct role in the diffusion of arsenic in this region, although an indirect role for vacancies as recombination centers for mobile interstitials is not precluded by these experiments. We conclude that interstitials dominate arsenic diffusion in the end-of-range region and beyond. Interpretation of the DSL data in the projected range region is complicated by Fermi level and segregation effects and no definitive conclusion can be reached about the point defect populations in this region.

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