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.

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.

The Effect of Si, F Implantation on the Formation and Light Emitting Properties of Porous Silicon

1993 ◽  
Vol 316 ◽  
Author(s):  
Lianwei Wang ◽  
Chenglu Lin ◽  
Ping Liu ◽  
Zuyao Zhou ◽  
Shichang Zou
Keyword(s):  
Porous Silicon ◽  
Ion Implantation ◽  
Porous Structure ◽  
Formation Mechanism ◽  
Point Defects ◽  
Electrochemical Etching ◽  
Amorphous Layer ◽  
Silicon Wafers ◽  
Porosity Distribution ◽  
Light Emitting

Abstract:The effect of ion implantation on the formation and light emitting properties of porous silicon is reported. Si + , F+ ions were implanted into silicon wafers before electrochemical etching process. The experiments showed that porous structure can be formed on the wafer containing amorphous layer, while the porosity distribution with the depth changed greatly compared with the anodized crystalline Si. The implantation of F+ ions greatly affects the formation mechanism. The creation of point defects leads to red-shift in photoluminescence measurements.

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.

Cryo-Implantation Technology for Controlling Defects and impurity out diffusion

2000 ◽  
Vol 610 ◽  
Author(s):  
Atsushi Murakoshi ◽  
Kyoichi Suguro ◽  
Masao Iwase ◽  
Mitsuhiro Tomita ◽  
Katsuya Okumura
Keyword(s):  
Ion Implantation ◽  
Substrate Temperature ◽  
Single Crystal ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Junction Depth ◽  
Si Substrate ◽  
Enhanced Diffusion ◽  
Pn Junction ◽  
Order Of Magnitude

AbstractWe propose a novel process module by using cryo-implantation and rapid thermal annealing (RTA). Boron or arsenic ions were implanted into a 8 inch (100) Si substrate which was cooled by using liquid nitrogen. The substrate temperature was controlled to be below at -160°C during ion implantation. It was found that an amorphous layer was formed by boron or arsenic implantation and the amorphous layer was completely recovered to a single crystal after annealing at 900°C for 30sec. No dislocation was observed in the implanted layer. It was also found that the thermal diffusion of boron was suppressed by cryo-implantation. PN junction depth was found to be about 10-20% shallower than that of room temperature implantation. These results suggest that transient enhanced diffusion of boron can be reduced by suppressing vacancy migration toward the surface during implantation. Cryo-implantation was found to be very effective in reducing defects and PN junction leakage was successfully reduced by one order of magnitude as compared with room temperature implantation.

On amorphous layer formation in silicon by ion implantation

1974 ◽  
Vol 22 (3) ◽  
pp. 205-208 ◽  
Author(s):  
J. C. Bourgoin ◽  
J. F. Morhange ◽  
R. Beserman
Keyword(s):  
Ion Implantation ◽  
Amorphous Layer ◽  
Layer Formation

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.

On the Influence of Boron-Interstitial Complexes on Transient Enhanced Diffusion

1999 ◽  
Vol 568 ◽  
Author(s):  
D. Stiebel ◽  
P. Pichler ◽  
H. Ryssel
Keyword(s):  
Ion Implantation ◽  
Experimental Results ◽  
Enhanced Diffusion ◽  
Transient Enhanced Diffusion ◽  
Dopant Atoms ◽  
Insight Into

ABSTRACTWe present new experimental results on the transient enhanced diffusion (TED) of boron after ion implantation. The investigation is focussed on effects that influence TED of shallow profiles in the absence of {311}-defects. Under these conditions, TED is mainly determined by the formation of boron-interstitial complexes (BIC). In addition, effects from the proximity of the surface become more and more important. Insight into the behavior of the dopant atoms is obtained by the comparison with simulations.

Furnace Anneal of A–Axis Sapphire Amorphised by Indium Ion Implantation

1988 ◽  
Vol 128 ◽  
Author(s):  
D. K. Sood ◽  
D. X. Cao
Keyword(s):  
Activation Energy ◽  
Ion Implantation ◽  
Amorphous Phase ◽  
Isothermal Annealing ◽  
Amorphous Layer ◽  
Surface Layers ◽  
Epitaxial Regrowth ◽  
Rapid Diffusion ◽  
Amorphous Surface ◽  
Higher Doses

ABSTRACTIndium implantation at 77°K into a–axis sapphire to peak concentrations of 6–45 mol % In produces amorphous surface layers. Isothermal annealing in Ar at temperatures between 600–900°C shows effects strongly dependent on ion dose. At lower doses <2×1016 In/cm2, the amorphous layer undergoes epitaxial regrowth as the amorphous to crystalline interface advances out towards the surface. Regrowth velocity is high in about the first half hour of the anneal. Regrowth obeys Arrhenius behaviour with an activation energy of 0.7eV for initial faster growth and 1.28eV for further anneal times. The amorphous phase transforms directly to ⊥-A12O3 without any evidence of an intermediary γ-phase. At higher doses, epitaxial regrowth is substantially retarded and rapid diffusion of In within the amorphous phase dominates.

The nature of defect layer formation for arsenic ion implantation

1983 ◽  
Vol 54 (5) ◽  
pp. 2316-2326 ◽  
Author(s):  
S. Prussin ◽  
David I. Margolese ◽  
Richard N. Tauber
Keyword(s):  
Ion Implantation ◽  
Defect Layer ◽  
Layer Formation
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