Formation of stable dopant interstitials during ion implantation of silicon

1986 ◽  
Vol 1 (3) ◽  
pp. 476-492 ◽  
Author(s):  
S.J. Pennycook ◽  
R.J. Culbertson ◽  
J. Narayan
Keyword(s):  
Ion Implantation ◽  
Direct Evidence ◽  
Solid Phase ◽  
Diffusion Mechanism ◽  
Transient Effects ◽  
Group V ◽  
Group Iii ◽  
Enhanced Diffusion ◽  
High Concentrations ◽  
Dopant Atoms

High concentrations of self-interstitials are trapped by dopant atoms during ion implantation into Si. For group V dopants, these complexes are sufficiently stable to survive solid-phase-epitaxial (SPE) growth but break up on subsequent thermal processing and cause a transientenhanced diffusion. Dopant diffusion coefficients are enhanced by up to five orders of magnitude over tracer values and are characterized by an activation energy of approximately one half of the tracer values. In the case of group III dopants, any complexes formed during implantation do not survive SPE growth but a second source of self-interstitials becomes significant and leads to similar transient effects. This is the damaged layer underlying the original amorphous/crystalline interface. These observations provide direct evidence for longrange self-interstitial migration in Si, and we believe these are the first observations of the interstitialcy diffusion mechanism with no vacancy contribution. We propose that the complexes are simply interstitial dopant atoms (in a split <100> interstitialcy configuration) that are particularly stable in the case of group V dopants. As they decay self-interstitials are released and cause the transient-enhanced diffusion.

From the Mystery to the Understanding of the Self-Interstitials in Silicon

1980 ◽  
Vol 2 ◽  
Author(s):  
W. Frank ◽  
A. Seeger ◽  
U. Gösele
Keyword(s):  
High Temperature ◽  
The Self ◽  
Experimental Conditions ◽  
Group V ◽  
Group Iii ◽  
Enhanced Diffusion ◽  
Self Diffusion ◽  
Thermally Activated ◽  
Temperature Equilibrium ◽  
K Concentration

ABSTRACTOur present knowledge on self-interstitials in silicon and the rôle these defects play under widely different experimental conditions are surveyed. In particular, the following phenomena involving self-interstitials either in supersaturations or under high-temperature thermal-equilibrium conditions are considered: mobility-enhanced diffusion of self-interstitials below liquid-helium temperature, thermally activated diffusion of self-interstitials at inter-mediate temperatures (14O K to 600 K), concentration-enhanced diffusion of Group-III or Group-V elements in silicon at higher temperatures, and— as examples for high-temperature equilibrium phenomena — self-diffusion and diffusion of gold in silicon. This leads to the picture that the self-interstitials in silicon may occur in different electrical charge states and possess dumbbell configurations or are extended over several atomic volumes at intermediate or high temperatures, respectively.

Phosphorus / Silicon Interstitial Annealing After Ion Implantation

2000 ◽  
Vol 610 ◽  
Author(s):  
P. H. Keys ◽  
R. Brindos ◽  
V. Krishnamoorthy ◽  
M. Puga-Lambers ◽  
K. S. Jones ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Secondary Ion Mass Spectrometry ◽  
Extended Defects ◽  
Enhanced Diffusion ◽  
Transmission Electron ◽  
Initial Nucleation ◽  
Primary Damage ◽  
Dopant Atoms ◽  
Phosphorus Doped ◽  
Secondary Ion

AbstractThe release of interstitials from extended defects after ion implantation acts as a driving force behind transient enhanced diffusion (TED). Implantation of Si+ ions into regions of phosphorus-doped silicon provides experimental insight into the interaction of silicon interstitials and dopant atoms during primary damage annealing. The presence of phosphorus influences the morphology of secondary defects during initial nucleation. Transmission electron microscopy (TEM) is used to differentiate between defect types and quantify the interstitials trapped in extended defects. This analysis reveals that phosphorus results in a reduction of interstitials trapped in observable extended defects. The interstitial flux released from the implanted region is also affected by the phosphorus doping. This phenomenon is closely studied using secondary ion mass spectrometry (SIMS) to monitor diffusion enhancements of dopant layers. Shifts in diffused dopant profiles are correlated with the different morphologies of the extended defects and the decay of the silicon interstitial supersaturation. This correlation is used to understand the interaction of excess silicon interstitials with phosphorus atoms.

Channeled‐ion implantation of group‐III and group‐V ions into silicon

1978 ◽  
Vol 49 (7) ◽  
pp. 3918-3921 ◽  
Author(s):  
T. Furuya ◽  
H. Nishi ◽  
T. Inada ◽  
T. Sakurai
Keyword(s):  
Ion Implantation ◽  
Group V ◽  
Group Iii

A Historical View of the Role of Ion-Implantation Defects in PN Junction Formation for Devices

2000 ◽  
Vol 610 ◽  
Author(s):  
R.B. Fair
Keyword(s):  
Ion Implantation ◽  
Group Iii ◽  
Enhanced Diffusion ◽  
Historical View ◽  
Implantation Damage ◽  
Long Time ◽  
Ultra Shallow Junctions ◽  
Induced Defects ◽  
Cs Ions

AbstractThe early use of ion bombardment of semiconductors for forming doped regions was viewed as a room-temperature process by solid-state scientists. Many interesting, but relatively useless devices were made by implanting species such as Na and Cs ions to form pn junctions from radiation damage or interstitial impurities. The revolutionary idea that one could implant Group III and V dopants into semiconductors and then heat the implanted substrate to above 800C didn't appear until 10 years after Shockley's 1954 patent. At that time, implantation damage became relatively unimportant as processes evolved with high temperature, long time diffusions. With the advent of rapid thermal processing, the attention shifted back to implantation-induced defects to explain transient-enhanced-diffusion effects. Today's challenges in forming ultra-shallow junctions by ion-implantation are in controlling and minimizing the damage structures that dominate junction activation and diffusion. Low-energy implants have been effective in this regard.

Mechanism of Enhanced Diffusion of Aluminum in 6H-SiC in the Process of High-Temperature Ion Implantation

1997 ◽  
Vol 504 ◽  
Author(s):  
Igor O. Usov ◽  
A. A. Suvorova ◽  
V. V. Sokolov ◽  
Y. A. Kudryavtsev ◽  
A. V. Suvorov
Keyword(s):  
Mass Spectrometry ◽  
Diffusion Coefficient ◽  
High Temperature ◽  
Ion Implantation ◽  
Room Temperature ◽  
Secondary Ion Mass Spectrometry ◽  
Diffusion Mechanism ◽  
Enhanced Diffusion ◽  
Sic Wafer ◽  
Secondary Ion

ABSTRACTThe diffusion of Al in 6H-SiC during high-temperature ion implantation was studied using secondary ion mass spectrometry. A 6H-SiC wafer was implanted with 50 keV Al ions to a dose of 1.4E16 cm−2 in the high temperature range 1300°–1800TC and at room temperature. There are two diffusion regions that can be identified in the Al profiles. At high Al concentrations the gettering related peak and profile broadening are observed. At low Al concentrations, the profiles have a sharp kink and deep penetrating diffusion tails. In the first region, the diffusion coefficient is temperature independent, while in the second it exponentially increases as a function of temperature. The Al redistribution can be explained with the substitutional-interstitial diffusion mechanism.

Solid phase equilibria in the Au-Ga-As, Au-Ga-Sb, Au-In-As, and Au-In-Sb ternaries

1986 ◽  
Vol 1 (2) ◽  
pp. 352-360 ◽  
Author(s):  
Tsai C. Thomas ◽  
R. Stanley Williams
Keyword(s):  
Gas Phase ◽  
Intermetallic Compounds ◽  
Small Volume ◽  
Solid Phase ◽  
Compound Semiconductors ◽  
The Other ◽  
Group V ◽  
X Ray ◽  
Group Iii ◽  
Pseudobinary Systems

The Au-Ga-As, Au-Ga-Sb, Au-In-As, and Au-In-Sb ternaries were surveyed using x-ray powder diffraction to determine which metallic phases exist at equilibrium with the III-V compound semiconductors. In closed, small-volume systems (i.e., formation of gas-phase products was prevented), Au does not react with GaAs but does react with the other III-V's investigated to produce Au-group III intermetallic compounds and another solid phase containing the group V element. However, each semiconductor formed pseudobinary systems with at least two different intermetallic compounds. The bulk phase diagrams determined in this study provide frameworks within which much of the experimental data in the literature concerning the products of reactions at Au/III-V interfaces can be understood.

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.

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.

Carbon incorporation into Si at high concentrations by ion implantation and solid phase epitaxy

1996 ◽  
Vol 79 (2) ◽  
pp. 637 ◽  
Author(s):  
J. W. Strane ◽  
S. R. Lee ◽  
H. J. Stein ◽  
S. T. Picraux ◽  
J. K. Watanabe ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Solid Phase ◽  
Solid Phase Epitaxy ◽  
Carbon Incorporation ◽  
High Concentrations

Ion Implantation Damage and B Diffusion in Low Energy B Implantation with Ge Preimplantation

1995 ◽  
Vol 396 ◽  
Author(s):  
M. Kase ◽  
H. Mori
Keyword(s):  
Ion Implantation ◽  
Diffusion Length ◽  
Solid Phase ◽  
Low Energy ◽  
Solid Phase Epitaxy ◽  
Light Damage ◽  
Sheet Resistivity ◽  
Enhanced Diffusion ◽  
Implantation Damage

AbstractFor low energy B (LEB) implantation into Si, the channeling tail is larger than for BF2+ implantation, so Ge+ preamorphization is expected to provide a shallower junction. We studied the Ge+ and B+ implantation damages and the damage-induced B diffusion. The substrate implanted Ge+ with 2×l014 cm-2, that is, a complete amorphization, retains less residual defects after RTA. However the sheet resistivity (S) is higher than the sample implanted with only LEB. Solid phase epitaxy (SPE) of amorphized layer causes B out-diffusion. The diffusion length of the amorphized substrate is smaller than that of LEB. We expect that the B diffusion is enhanced by the LEB damage, which corresponds to the enhanced diffusion of light damage.

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