Amorphization of elemental and compound semiconductors upon ion implantation

1991 ◽  
Vol 6 (5) ◽  
pp. 1048-1054 ◽  
Author(s):  
K.S. Jones ◽  
C.J. Santana
Keyword(s):  
Monte Carlo ◽  
Ion Implantation ◽  
Density Distribution ◽  
Bond Energy ◽  
Ion Beam ◽  
Compound Semiconductors ◽  
Amorphous Layer ◽  
Thermochemical Data ◽  
Energy Estimates ◽  
Cross Sectional

Cross-sectional TEM studies of ion implantation induced amorphization in a large number of semiconductors have been performed. Samples of Si, AlAs, GaAs, GaP, GaSb, InP, InAs, and ZnSe were simultaneously implanted at 77 K with 20 keV Si+ at doses between 1 × 1014/cm2 and 1 × 1016/cm2. A dose of 1 × 1015/cm2 minimized the ion beam induced epitaxial crystallization and sputtering effects. The depth of the amorphous layer at this dose was compared with Monte Carlo damage density distribution calculations (TRIM'90). The threshold damage density (TDD) necessary for amorphization was determined for each compound. The values of the threshold damage density vary from as low as 2.4 × 1019 keV/cm3 for InAs up to 7.3 × 1020 keV/cm3 for AlAs. ZnSe never became amorphous and GaSb exhibited an unusual disordering after the highest dose. The values of the threshold damage density for the various compositions were compared with known thermochemical data and several bond energy estimates. No single calculation explained all of the trends observed.

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]

Ion Beam Synthesis of IrSi3 by 1-MeV Ir Ion Implantation into Si(111)

1993 ◽  
Vol 320 ◽  
Author(s):  
T. P. Sjoreen ◽  
H.- J. Hinneberg
Keyword(s):  
Ion Implantation ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Processing Parameters ◽  
Cross Sectional ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Nearly Continuous ◽  
Substrate Temperatures ◽  
Different Doses

ABSTRACTThe formation of a Si/IrSi3/Si heterostructurie by 1-MeV Ir ion implantation and subsequent annealing has been studied for different doses (0.1-2.25 × 1017 Ir/cm2), substrate temperatures (450°-600°C) and annealing temperatures (1000°-1200°C) using Rutherford backscattering spectrometry, ion channeling and cross-sectional transmission electron microscopy. The heterostructure formation is observed to depend strongly on the processing conditions. The best structure, nearly continuous and precipitate-free, is obtained by implanting 1.8-2.0× 1017 1r/cm2 at a substrate temperature of 550°C and annealing at 1100°C for 5 h. A stoichiometric IrSi3 layer can also be produced by furnace annealing at 1150°C for 1 h or by rapid-thermal-annealing at 1200°C for 3 min. Other substrate temperatures generally lead to a structure with a discontinuous IrSi3 layer frequently interrupted by large surface precipitates or islands. The origin of these islands, as well as the dependence of the heterostructure on processing parameters, is discussed.

Ion Beam Synthesis of IrSi3 by 1-MeV Ir Ion Implantation into Si(111)

1993 ◽  
Vol 316 ◽  
Author(s):  
T. P. Sjoreen ◽  
H.-J. Hinneberg
Keyword(s):  
Ion Implantation ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Processing Parameters ◽  
Cross Sectional ◽  
Ion Channeling ◽  
Transmission Electron ◽  
Nearly Continuous ◽  
Substrate Temperatures ◽  
Different Doses

ABSTRACTThe formation of a Si/IrSi3/Si heterostructure by 1-MeV Ir ion implantation and subsequent annealing has been studied for different doses (0.1-2.25 × 1017 Ir/cm2), substrate temperatures (450°-600°C) and annealing temperatures (1000°-1200°C) using Rutherford backscattering spectrometry, ion channeling and cross-sectional transmission electron microscopy. The heterostructure formation is observed to depend strongly on the processing conditions. The best structure, nearly continuous and precipitate-free, is obtained by implanting 1.8-2.0 × 1017 Ir/cm2 at a substrate temperature of 550°C and annealing at 1100°C for 5 h. A stoichiometric IrSi3 layer can also be produced by furnace annealing at 1150°C for 1 h or by rapid-thermal-annealing at 1200°C for 3 min. Other substrate temperatures generally lead to a structure with a discontinuous IrSi3 layer frequently interrupted by large surface precipitates or islands. The origin of these islands, as well as the dependence of the heterostructure on processing parameters, is discussed.

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.

scholarly journals Investigation of Chemomechanical Effects on Sapphire Surfaces Modified by Ion-Implantation-Induced Carbon Impurities

2021 ◽  
Vol 7 (2) ◽  
Author(s):  
Arti Yadav ◽  
Noushin Moharrami ◽  
Steve Bull
Keyword(s):  
Ion Implantation ◽  
Ion Beam ◽  
Water Layer ◽  
Adsorbed Water ◽  
Sample Surface ◽  
Amorphous Layer ◽  
Near Surface ◽  
Sapphire Surface ◽  
Carbon Impurities ◽  
High Doses

AbstractModification of the chemomechanical behaviour of the surface of sapphire by ion implantation to improve its near-surface mechanical properties has been investigated. 300 keV Ti+ ions at various doses were implanted and the concentration and damage profiles characterised using Rutherford Backscattering (RBS). At high doses (≥ 3 × 1016 Ti+ cm−2), a surface amorphous layer is formed due to implantation-induced damage. Nanoindentation was used to determine the hardness behaviour of the ion-implanted layer. Hardness increases at low implantation doses, associated with implantation-induced damage, but it is also observed that chemomechanical softening of the surface is reduced due to the removal of adsorbed water. In situ Raman scattering measurements demonstrate this removal at low doses and the re-establishment of the adsorbed water layer at high doses. The adsorption process is changed due to the introduction of carbon into the sapphire surface during implantation. For the optimum-implanted dose, the water readsorption does not recur even several years after the implantation treatment was first carried out. The loss of water adsorption is related to the formation of a non-polar carbonaceous layer on the sapphire surface by cracking of back-streamed diffusion pump oil deposited on the sample surface by inelastic collisions with the ion beam. Based on this study, it is concluded that ion implantation with an appropriate ion species and dose can control the chemomechanical effect and improve the hardness of ceramics, such as sapphire.

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.

Sign in / Sign up

Export Citation Format

Share Document