Flux Dependence of Amorphous Layer Formation and Damage Annealing in Room Temperature Implantation of Boron into Silicon

1993 ◽  
Vol 316 ◽  
Author(s):  
Robert Simonton ◽  
Jinghong Shi ◽  
Ted Boden ◽  
Philippe Maillot ◽  
Larry Larson
Keyword(s):  
Sheet Resistance ◽  
Room Temperature ◽  
Strong Dependence ◽  
Amorphous Layer ◽  
High Flux ◽  
Dislocation Loops ◽  
Layer Formation ◽  
Cross Sectional ◽  
Implantation Temperature ◽  
Beam Currents

ABSTRACTWe implanted <100> silicon 200mm wafers with 20keV 11B+ to a fluence of 5×1015 atoms/ cm2 using beam currents from 1-7mA, which produced flux of about 50-350µA/cm2. The implant temperature of all wafers rose no more than five degrees above room temperature, regardless of flux. Cross sectional TEM images (as-implanted) of the highest flux samples revealed a continuous amorphous layer from the implanted surface to a depth of about 530Å. The high flux and <30°C implantation temperature allowed amorphous layer formation even with this moderate boron fluence, as was suggested by Jones, et.al.1. We observed a strong dependence of as-implanted damage on boron flux, as previously reported by Eisen and Welch2. After 900°C, 20 sec RTA, the highest flux samples had 50% lower sheet resistance than the lowest flux samples, due to better activation, as observed in SRP. When a 1050°C, 15 sec RTA was employed, this sheet resistance and activation dependence on flux disappeared. Cross sectional TEM images revealed that the size and number of the Type II end of range defects , which were centered near the amorphous and crystalline as-implanted interface, in the highest flux samples were smaller than the Type 1 dislocation loops centered about the peak disorder in the lowest flux samples after RTA. SIMS and SRP profiles indicated that transient enhanced diffusion during the 900°C, 20 sec RTA may have been reduced in the highest flux samples. Based on these observations and on previous reports, we conclude that sufficiently high flux during room temperature boron implantation will produce a continuous amorphous layer with doses that are appropriate for p-type source/drain formation. The amorphous layer will produce improved activation and damage annealing behavior in subsequent RTA, particularly as the RTA temperature is reduced.

Enhanced Boron Diffusion in Amorphous Silicon

2004 ◽  
Vol 810 ◽  
Author(s):  
J.M. Jacques ◽  
N. Burbure ◽  
K.S. Jones ◽  
M.E. Law ◽  
L.S. Robertson ◽  
...  
Keyword(s):  
Amorphous Silicon ◽  
Room Temperature ◽  
Solid Phase ◽  
Amorphous Layer ◽  
Boron Diffusion ◽  
Cross Sectional ◽  
Enhanced Diffusion ◽  
Transmission Electron ◽  
Variable Angle Spectroscopic Ellipsometry ◽  
Secondary Ion

ABSTRACTIn prior works, we demonstrated the phenomenon of fluorine-enhanced boron diffusion within self-amorphized silicon. Present studies address the process dependencies of low temperature boron motion within ion implanted materials utilizing a germanium amorphization. Silicon wafers were preamorphized with either 60 keV or 80 keV Ge+ at a dose of 1×1015 atoms/cm2. Subsequent 500 eV, 1×1015 atoms/cm211B+ implants, as well as 6 keV F+ implants with doses ranging from 1×1014 atoms/cm2 to 5×1015 atoms/cm2 were also done. Furnace anneals were conducted at 550°C for 10 minutes under an inert N2 ambient. Secondary Ion Mass Spectroscopy (SIMS) was utilized to characterize the occurrence of boron diffusion within amorphous silicon at room temperature, as well as during the Solid Phase Epitaxial Regrowth (SPER) process. Amorphous layer depths were verified through Cross-Sectional Transmission Electron Microscopy (XTEM) and Variable Angle Spectroscopic Ellipsometry (VASE). Boron motion within as-implanted samples is observed at fluorine concentrations greater than 1×1020 atoms/cm3. The magnitude of the boron motion scales with increasing fluorine dose and concentration. During the initial stages of SPER, boron was observed to diffuse irrespective of the co-implanted fluorine dose. Fluorine enhanced diffusion at room temperature does not appear to follow the same process as the enhanced diffusion observed during the regrowth process.

Temperature Dependence of Damage in Boron-Implanted Silicon

1989 ◽  
Vol 147 ◽  
Author(s):  
G. Ottaviani ◽  
F. Nava ◽  
R. Tonini ◽  
S. Frabboni ◽  
G. F. Cerofolini ◽  
...  
Keyword(s):  
Room Temperature ◽  
Amorphous Layer ◽  
Systematic Investigation ◽  
Vacuum Furnace ◽  
Cross Sectional ◽  
Ion Channeling ◽  
Projected Range ◽  
Transmission Electron ◽  
Boron Implantation ◽  
Residual Damage

AbstractWe have performed a systematic investigation of boron implantation at 30 keV into <100> n-type silicon in the 77 –300 K temperature range and mostly at 9×1015 cm−2 fluence. The analyses have been performed with ion channeling and cross sectional transmission electron microscopy both in as-implanted samples and in samples annealed in vacuum furnace at 500 °C and 850 °C for 30 min. We confirm the impossibility of amorphization at room temperature and the presence of residual damage mainly located at the boron projected range. On the contrary, a continuous amorphous layer can be obtained for implants at 77 K and 193 K; the thickness of the implanted layer is increased by lowering the temperature, at the same time the amorphous-crystalline interface becomes sharper. Sheet resistance measurements performed after isochronal annealing shows an apparent reverse annealing of the dopant only in the sample implanted at 273 K. The striking differences between light and heavy ions observed at room temperature implantation disappears at 77 K and full recovery with no residual damage of the amorphous layer is observed.

Application of Low Temperature InP Wafer Bonding Towards Optical Add/Drop Multiplexer Realization

2004 ◽  
Vol 829 ◽  
Author(s):  
J. Arokiaraj ◽  
S. Vicknesh ◽  
A. Ramam
Keyword(s):  
Indium Phosphide ◽  
Wafer Bonding ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Cross Sectional ◽  
Current Voltage ◽  
High Resolution Tem ◽  
Higher Temperature ◽  
Current Voltage Characteristics ◽  
Bonding Method

AbstractA method to bond directly Indium Phosphide to Indium phosphide at low temperatures has been realized. The treatment of wafers in HF and oxygen plasma exposure prior to bonding is helpful in activating the surface of the wafers at room temperature. This surface activation is useful to bond the wafers at room temperature. Further higher temperature (220°C) treatment with pressure, aided in the completion of the wafer bonding process. The interface of the bonded structures revealed a very thin amorphous layer of oxide when examined under high resolution TEM. Cross-sectional micro Raman measurements revealed signatures corresponding to some disordered associated layer at the interface. Current-Voltage characteristics exhibited ohmic conduction across the interface. The wafer bonding method developed would serve as a useful tool for the fabrication of photonic and optoelectronic devices.

Implant Damage in AlGaAs Based Superlattices and Alloys at 77K

1989 ◽  
Vol 147 ◽  
Author(s):  
E. A. Dobisz ◽  
H. Dietrich ◽  
A. W. McCormick ◽  
J. P. Harbison
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Layer Thickness ◽  
Room Temperature ◽  
Amorphous Layer ◽  
Current Work ◽  
Cross Sectional ◽  
Bulk Gaas ◽  
Transmission Electron ◽  
Extensive Damage

AbstractPreviously, it was shown that superlattices implanted with Si at 77K, exhibited more extensive damage and uniform compositional mixing upon subsequent annealing than samples implanted at room temperature.[l,2] The current work focuses on the damage in samples implanted with Si at 77K. The study shows that for a given dose, the amount of damage depends upon the layer thickness and the composition. Specimens of bulk GaAs, Al 3Ga. 7As, 7.5 nm GaAs -10 nm Al. 3Ga. 7As superlattice (SL1), 5.5 nm GaAs −3.5 nm AlAs superlattice (SL2), and 8.0 nm GaAs −8.0 nm AlAs superlat-tice (SL3) were implanted at 77K with 100 KeV Si, with doses ranging from 3 × 1013 cm−2 to 1 × 1015 cm−2. The samples were examined by ion channelling and cross sectional transmission electron microscopy (TEM). At 77K and a dose of 1 × 1014 cm−2, the GaAs and SLi showed an amorphous layer, while no damage peak was observed in SL2. The 77K amorphization thresholds of the Al 3Ga. 7As alloy, SL2, and SL3 were 2.5 × 1014 cm−2, 4 × 1014 cm−2, and 1 × 1015 cm−2 respectively. The sharpness of the amorphization threshold varied with the material.

Germanium Implantation into Silicon: An Alternate Pre-Amorphization/Rapid Thermal Annealing Procedure for Shallow Junction Technology

1983 ◽  
Vol 23 ◽  
Author(s):  
D.K. Sadana ◽  
E. Myers ◽  
J. Liu ◽  
T. Finstad ◽  
G.A. Rozgonyi
Keyword(s):  
Thermal Annealing ◽  
Rapid Thermal Annealing ◽  
Surface Region ◽  
Amorphous Layer ◽  
High Dose ◽  
Dislocation Loops ◽  
Cross Sectional ◽  
Defect Clusters ◽  
Ion Damage ◽  
Free Material

ABSTRACTGermanium implantation into Si was conducted to pre-amorphize the-si surface layer prior to a shallow/high dose (42 keV, 2 × 1015 cm−2) BF2 implant. Cross-sectional transmission electron microscopy showed that rapid thermal annealing (RTA) of the amorphous layer (without BF2 ) leaves defect-free material in the implanted region. Only a discrete layer of small (∼300Å) dislocation loops due to straggling ion damage was found to be present at a depth corresponding to the amorphous/crystalline interface. RTA of the amorphous layer with the BF2 creatpd a high density of uniformly. distributed fine defect clusters (∼50Å) in the surface region (0–500Å) in addition to the straggling ion damage. Boron and F profiles obtained by secondary ion mass spectrometry from the unannealed and rapid thermally annealed samples showed the presence of high concentrations of these impurities in the surface region where the fine defect clusters were observed. A comparison of the RTA behavior of the pre-amorphized surface layers (with or without BF2 ) produced by Ge and self-implantation is presented.

Defect Structures Generated by Buried Amorphous Layer Regrowth in Arsenic Implanted Silicon

1986 ◽  
Vol 71 ◽  
Author(s):  
Kevin S. Jones ◽  
S. Prussin
Keyword(s):  
Ion Beam ◽  
Amorphous Layer ◽  
High Energy ◽  
Dislocation Loops ◽  
Furnace Annealing ◽  
Cross Sectional ◽  
Plan View ◽  
Extrinsic Dislocation ◽  
Shear Type ◽  
Type Dislocation

AbstractPlan-view and 90° cross-sectional TEM examination was used to investigate the correlation between the type of amorphous layer produced and the resulting defect structure observed upon annealing. Both <100> and <111> Si wafers were ion implanted with high energy (190 keV) arsenic over a range of doses(1 × 1015/cm2 to 5 × 1015/cm2). A Wayflow endstation was used allowing ion beam induced epitaxial crystallization (IBIEC)[8] or dynamic annealing of the sample to occur. Implanted <111> Si is shown to form a continuous amorphous layer up to the surface, while <100> implanted Si forms a buried amorphous layer. The regrowth of the buried x-layer by furnace annealing is shown to be responsible for the formation of shear type dislocation loops at the interface where the two x/c regrowth fronts meet (catagory IV defects).[7] However if the buried layer is regrown by dynamic annealing a different structure results.In addition to using <111> wafers, other parameter changes which resulted in the formation of surface amorphous layers included decreasing the implant energy from 190 keV to 100 keV, or implanting the wafer at 77K instead of using the Wayflow endstation. Regrowth of the surface amorphous layers produced by these changes did not result in the formation of shear type dislocation loops. Further annealing of the 100 keV Wayflow implant and the 190 keV 77K implant at 900°C for 30 minutes resulted in the formation of small prismatic extrinsic dislocation loops beneath the location of the original amorphous/crystalline interface (catagory II defects).[71]

The Effect of Implanted Gallium on the Recrystallization of Amorphous Layers formed during FIB Milling of Silicon

2001 ◽  
Vol 7 (S2) ◽  
pp. 958-959
Author(s):  
S. Rubanov ◽  
P.R. Munroe
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Amorphous Layer ◽  
High Energy ◽  
Specimen Preparation ◽  
Silicon Sample ◽  
Cross Sectional ◽  
Wide Range ◽  
Average Size ◽  
Beam Currents

The focused ion beam (FIB) miller allows preparation of site-specific transmission electron microscopy (TEM) specimens from a wide range of materials in both cross-sectional and planar configurations [1,2]. However, radiation damage during exposure to the high-energy gallium beam may result in the formation of amorphous regions on thin film specimens. The thickness of such damage layers, on both sides of a TEM specimen, is comparable with the thickness required for lattice imaging. For example, the thickness of an amorphous layer in Si after 30 kV Ga+ FIB processing has been reported in the range from 15 [3] to 28 nm [4]. This problem limits the capabilities of FIB sample fabrication.The aim of this study was to investigate, in detail, the structure, composition and the thickness of the damage layers in Si specimens after milling with a gallium ion beam. Using a FEI xP200 FIB system, with 30 kV Ga+ ions, a row of trenches on a silicon sample was milled under different beam currents ranging from 150 to 6600 pA. The average size of such trenches was 15×10 μm wide and 1 μm deep. The trenches were then removed from the FIB and sputter coated with a thick Au film to preserve the trench surfaces from further damage during subsequent TEM specimen preparation steps. Cross-sectional TEM specimens of the trench walls were then prepared using standard FIB procedures [5]. Observations were made using a Philips CM 200 Field Emission Gun TEM operating at an accelerating voltage of 200 kV.

Ion Damage Studies in GaAs/Al0.6Ga0.4As/GaAs Heterostructures

1993 ◽  
Vol 316 ◽  
Author(s):  
B.A. Turkot ◽  
D.V. Forbes ◽  
H. Xiao ◽  
I.M. Robertson ◽  
J.J. Coleman ◽  
...  
Keyword(s):  
Room Temperature ◽  
Defect Density ◽  
Ion Irradiation ◽  
Amorphous Layer ◽  
Damage Distribution ◽  
Cross Sectional ◽  
Bottom Interface ◽  
Damage Structure ◽  
High Resolution Tem ◽  
Degree Of Recovery

ABSTRACTThe development of the damage structure produced in (100) GaAs/Al0.6Ga0.4As/GaAs by 1 MeV Kr+ ion irradiation at 77 and 293 K has been investigated by RBS channeling and cross-sectional high-resolution TEM techniques. Following an implantation to a dose of 1014 ions cm-2 at 77 K, RBS channeling spectra indicate that the Al0.6Ga0.4 layer contained a high defect density and was possibly amorphous. Warming to room temperature resulted in a change in the channeling spectrum, which indicated that the damage in the Al0.6Ga0.4As layer had partially recovered. The degree of recovery was greatest at the GaAs/ Al0.6Ga0.4As interface, and decreased with increasing depth. TEM observations show the damage in the Al0.6Ga0.4As to be comprised of planar defects, the density of which increases with depth, and an amorphous layer at the bottom interface. This difference in the damage distribution is consistent with the asymmetry in the channeling spectrum. A model based on the depth variation of cascade density is proposed to account for the observations.

Formation of β-FeSi2, by thermal annealing of Fe-implanted (001) Si

1993 ◽  
Vol 51 ◽  
pp. 808-809
Author(s):  
X.W. Lin ◽  
Z. Liliental-Weber ◽  
J. Washburn ◽  
J. Desimoni ◽  
H. Bernas
Keyword(s):  
Thermal Annealing ◽  
Room Temperature ◽  
Solid Phase ◽  
Ion Beam ◽  
High Resolution Electron Microscopy ◽  
Optoelectronic Device ◽  
Amorphous Layer ◽  
Cross Sectional ◽  
Resolution Electron ◽  
Device Technology

Epitaxy of semiconducting β-FeSi2 on Si is of interest for optoelectronic device technology, because of its direct bandgap of ≈0.9 eV. Several techniques, including solid phase epitaxy (SPE) and ion beam synthesis, have been successfully used to grow β-FeSi2 on either Si (001) or (111) wafers. In this paper, we report the epitaxial formation of β-FeSi2 upon thermal annealing of an Fe-Si amorphous layer formed by ion implantation.Si (001) wafers were first implanted at room temperature with 50-keV Fe+ ions to a dose of 0.5 - 1×1016 cm−2, corresponding to a peak Fe concentration of cp ≈ 2 - 4 at.%, and subsequently annealed at 320, 520, and 900°C, in order to induce SPE of the implanted amorphous layer. Cross-sectional high-resolution electron microscopy (HREM) was used for structural characterization.We find that the implanted surface layer ( ≈100 nm thick) remains amorphous for samples annealed at 320°C for as long as 3.2 h, whereas annealing above 520°C results in SPE of Si, along with precipitation of β-FeSi2.

Heterogeneous Precipitation at Dislocations

1969 ◽  
Vol 27 ◽  
pp. 70-71
Author(s):  
A. K. Eikum
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
Dislocation Loops ◽  
Silver Alloys ◽  
Heterogeneous Precipitation ◽  
Precipitation Phenomena ◽  
Aluminum Base ◽  
Silver Atoms

Precipitation phenomena in concentrated aluminum-base silver alloys have been studied with a variety of techniques including electron microscopy. The purpose of the present work was to investigate the dislocation reactions that occur as silver atoms precipitate (or segregate) under a relatively low supersaturation. Specimens (0.1 mm thick) of Al-1 at. % Ag were quenched from ~500°C into an oil bath at room temperature and aged 30 min. at 265°C. The initial configurations available as sites for heterogeneous precipitation will therefore include perfect prismatic dislocation loops, Frank sessile loops and random segments of grown-in dislocations.

Sign in / Sign up

Export Citation Format

Share Document