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

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.

Download Full-text

Phosphorus / Silicon Interstitial Annealing After Ion Implantation

MRS Proceedings ◽

10.1557/proc-610-b6.6 ◽

2000 ◽

Vol 610 ◽

Cited By ~ 1

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.

Download Full-text

The Effect of Impurities on Diffusion and Activation of ion Implanted Boron in Silicon

MRS Proceedings ◽

10.1557/proc-610-b5.8 ◽

2000 ◽

Vol 610 ◽

Cited By ~ 3

Author(s):

L. S. Robertson ◽

R. Brindos ◽

K. S. Jones ◽

M. E. Law ◽

D. F. Downey ◽

...

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Chemical Species ◽

Amorphous Layer ◽

Boron Diffusion ◽

Diffusion Enhancement ◽

Species Effect ◽

Hall Effect Measurements ◽

High Doses ◽

Ion Profiles ◽

Ion Implanted

AbstractThe interaction between boron and silicon interstitials caused by ion implant damage is a physical process which hinders the formation of ultra-shallow, low resistivity junctions. The possibility of mitigating the effective interstitial point defect population via introduction of nonmetallic impurities in ion implanted silicon has been investigated. Amorphization of a n-type Czochralski wafer was achieved using a series of Si+ implants of 40 keV and 150 keV, each at a dose of 1×1015/cm2. The Si+ implants produced a 2800Å deep amorphous layer, which was then implanted with 8 keV 1×1014/cm2 B+. The samples were then implanted with high doses of either carbon, oxygen, sulfur, chlorine, selenium, or bromine. The implant energies of the impurities were chosen such that the damage and ion profiles of the impurity were contained within the amorphous layer. This allowed for the chemical species effect to be studied independent of the implant damage caused by the impurity 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. Hall effect measurements were used to study the dopant activation. Transmission electron microscopy (TEM) was used to study the end-of-range defect evolution. The addition of carbon and chlorine appear to reduce the boron diffusion enhancement compared to the boron control. Carbon and chlorine also appear to prevent boron out-diffusion during annealing compared to the control, which exhibited 20% dose loss following annealing.

Download Full-text

Modeling and Experiments of Boron Diffusion During Sub-Millisecond Non-Melt Laser Annealing in Silicon

MRS Proceedings ◽

10.1557/proc-0912-c05-06 ◽

2006 ◽

Vol 912 ◽

Cited By ~ 8

Author(s):

Taiji Noda ◽

Susan Felch ◽

Vijay Parihar ◽

Christa Vrancken ◽

Tom Janssens ◽

...

Keyword(s):

Laser Annealing ◽

Secondary Ion Mass Spectrometry ◽

Kinetic Monte Carlo ◽

Amorphous Layer ◽

Dislocation Loops ◽

Boron Diffusion ◽

Transmission Electron ◽

Defect Evolution ◽

Evolution Behavior ◽

Boron Diffusivity

AbstractBoron diffusion and defect evolution during sub-millisecond (ms) laser annealing with partial SPER are investigated using secondary ion mass spectrometry and transmission electron microscopy. Boron diffusivity enhancement in amorphous-Si is observed during partial SPER at 550 °C. It is shown that boron diffusion during the laser annealing process is a 2-step diffusion (SPER + Laser). The depth of the amorphous layer affects the dopant activation behavior. During sub-ms laser annealing, end-of-range defects are formed and show an evolution behavior. {311} defects cannot completely transfer to dislocation loops after 1300 °C laser annealing. It is considered that the thermal budget of sub-ms laser is too small for full defect evolution. Atomistic diffusion modeling using a kinetic Monte Carlo method can explain the defect behavior during laser annealing.

Download Full-text

The Role of Ion Mass on End-of-Range Damage in Shallow Preamorphizing Silicon

MRS Proceedings ◽

10.1557/proc-669-j3.6 ◽

2001 ◽

Vol 669 ◽

Author(s):

Mark H. Clark ◽

Kevin S. Jones ◽

Tony E. Haynes ◽

Charles J. Barbour ◽

Kenneth G. Minor ◽

...

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Secondary Ion Mass Spectrometry ◽

Amorphous Layer ◽

Cross Sectional ◽

Plan View ◽

Enhanced Diffusion ◽

Transmission Electron ◽

Marker Layer ◽

Process Simulator

ABSTRACTPreamorphization is commonly used to form shallow junction in silicon CMOS devices. The purposeof this experiment was to study the effect of the preamorphizing species' mass on the interstitial concentration at the end-of-range (EOR). Isovalent species of Si, Ge, Sn and Pb were compared. Silicon wafers with a buried boron marker layer (4700 Å deep) were amorphized using implants of 22 keV 28Si+, 32 keV73Ge+, 40 keV 119Sn+ or 45 keV 207Pb+, which resulted in similar amorphous layer depths. All species were implanted at a dose of 5×1014 /cm2. Cross-sectional transmission electron microscopy (XTEM) was used tomeasure amorphous layer depths (approximately 400 Å). Post-implantation anneals were performed at 750 °C for 15 minutes. Plan-view transmission electron microscopy (PTEM) was used to observe and quantify the EOR defect population upon annealing. Secondary ion mass spectrometry (SIMS) was used to monitor the transient enhanced diffusion (TED) of the buried boron marker layer resulting from the EOR damage introduced by the amorphizing implants. Based upon the SIMS results Florida Object Oriented Process Simulator (FLOOPS) calculated the resulting time average diffusivity enhancements. Results showed that increasing the ion mass over a significant range (28 to 207 AMU) not only affects the quantity and type of damage that occurs at the EOR, but results in a reduced diffusivity enhancement.

Download Full-text

Effects of Concurrent Co or Ti Silicidation on Transient Diffusion and End-of-Range Damage in Phosphorus Implanted Silicon

MRS Proceedings ◽

10.1557/proc-262-701 ◽

1992 ◽

Vol 262 ◽

Cited By ~ 1

Author(s):

J.W. Honeycutt ◽

J. Ravi ◽

G. A. Rozgonyi

Keyword(s):

Secondary Ion Mass Spectrometry ◽

Complete Removal ◽

Dislocation Loops ◽

Enhanced Diffusion ◽

Depth Profiles ◽

Enhanced Dissolution ◽

Implantation Damage ◽

Transmission Electron ◽

Defect Behavior ◽

Secondary Ion

ABSTRACTThe effects of Ti and Co silicidation on P+ ion implantation damage in Si have been investigated. After silicidation of unannealed 40 keV, 2×1015 cm-2 P+ implanted junctions by rapid thermal annealing at 900°C for 10–300 seconds, secondary ion mass spectrometry depth profiles of phosphorus in suicided and non-silicided junctions were compared. While non-silicided and TiSi2 suicided junctions exhibited equal amounts of transient enhanced diffusion behavior, the junction depths under COSi2 were significantly shallower. End-of-range interstitial dislocation loops in the same suicided and non-silicided junctions were studied by planview transmission electron microscopy. The loops were found to be stable after 900°C, 5 minute annealing in non-silicided material, and their formation was only slightly effected by TiSi2 or COSi2 silicidation. However, enhanced dissolution of the loops was observed under both TiSi2 and COSi2, with essentially complete removal of the defects under COSi2 after 5 minutes at 900°C. The observed diffusion and defect behavior strongly suggest that implantation damage induced excess interstitial concentrations are significantly reduced by the formation and presence of COSi2, and to a lesser extent by TiSi2. The observed time-dependent defect removal under the suicide films suggests that vacancy injection and/or interstitial absorption by the suicide film continues long after the suicide chemical reaction is complete.

Download Full-text

Measurements of the Diffusion of Iron and Carbon in Single Crystal NiAl using Ion Implantation and Secondary Ion Mass Spectrometry

MRS Proceedings ◽

10.1557/proc-527-227 ◽

1998 ◽

Vol 527 ◽

Author(s):

R. J. Hanrahan ◽

S. P. Withrow ◽

M. Puga-Lambers

Keyword(s):

Mass Spectrometry ◽

Ion Implantation ◽

Single Crystal ◽

Secondary Ion Mass Spectrometry ◽

Tracer Diffusion ◽

Dynamic Strain ◽

Enhanced Diffusion ◽

Ion Mass Spectrometry ◽

Impurity Elements ◽

Secondary Ion

ABSTRACTClassical diffusion measurements in intermetallic compounds are often complicated by low diffusivities or low solubilities of the elements of interest. Using secondary ion mass spectrometry for measurements over a relatively shallow spatial range may be used to solve the problem of low diffusivity. In order to simultaneously obtain measurements on important impurity elements with low solubilities we have used ion implantation to supersaturate a narrow layer near the surface. Single crystal NiAl was implanted with either 12C or both 56Fe and 12C in order to investigate the measurement of substitutional (Fe) versus interstitial (C) tracer diffusion and the cross effect of both substitutional and interstitial diffusion. When C alone was implanted negligible diffusion was observed over the range of times and temperatures investigated. When both Fe and C were implanted together significantly enhanced diffusion of the C was observed, which is apparently associated with the movement of Fe. This supports one theory of dynamic strain aging in Fe alloyed NiAl.

Download Full-text

Damage calibration concept and novel B cluster reaction model for B transient enhanced diffusion over thermal process range from 600°C (839 h) to 1100°C (5 s) with various ion implantation doses and energies

International Electron Devices Meeting. IEDM Technical Digest ◽

10.1109/iedm.1997.650433 ◽

2002 ◽

Cited By ~ 5

Author(s):

K. Suzuki ◽

T. Miyashita ◽

Y. Tada ◽

A. Hoefler ◽

N. Strecker ◽

...

Keyword(s):

Ion Implantation ◽

Thermal Process ◽

Reaction Model ◽

Enhanced Diffusion ◽

Transient Enhanced Diffusion ◽

Cluster Reaction

Download Full-text

Suppression of transient enhanced diffusion following in situ photoexcitation during boron ion implantation

Applied Physics Letters ◽

10.1063/1.114752 ◽

1995 ◽

Vol 67 (15) ◽

pp. 2158-2160 ◽

Cited By ~ 6

Author(s):

J. Ravi ◽

Yu. Erokhin ◽

G. A. Rozgonyi ◽

C. W. White

Keyword(s):

Ion Implantation ◽

Enhanced Diffusion ◽

Transient Enhanced Diffusion

Download Full-text

Synthesis of (SIC)3N4 Films by Ion Implantation

MRS Proceedings ◽

10.1557/proc-316-765 ◽

1993 ◽

Vol 316 ◽

Cited By ~ 3

Author(s):

C. Uslu ◽

D. H. Lee ◽

Y. Berta ◽

B. Park ◽

N. N. Thadhani ◽

...

Keyword(s):

Ion Implantation ◽

Amorphous Layer ◽

Cubic Phase ◽

X Ray Diffraction ◽

Nitrogen Implantation ◽

Transmission Electron ◽

Position Sensitive ◽

Nitrogen Ions ◽

Substrate Temperatures ◽

New Phase

ABSTRACTWe have investigated the synthesis of carbon-silicon-nitride compounds by ion implantation. In these experiments, 100 keV nitrogen ions were implanted into polycrystalline β-SiC (cubic phase) at various substrate temperatures and ion doses. These thin films were characterized in detail by x-ray diffraction with a position-sensitive detector, transmission electron microscopy with chemical analysis, and Rutherford backscattering spectroscopy. The as-implanted samples show a buried amorphous layer at a depth of 170 nm. The peak concentration of nitrogen saturates at approximately 45 at. % with doses above ~9.0×1017 N/cm2 at 860°C. These results suggest formation of a new phase by nitrogen implantation into β-SiC.

Download Full-text