The Competition between Ion Beam Induced Epitaxial Crystallization and Amorphization in Silicon: The Role of the Divacancy

1986 ◽  
Vol 74 ◽  
Author(s):  
J. Linnros ◽  
R. G. Elliman ◽  
W. L. Brown
Keyword(s):  
Activation Energy ◽  
Dose Rate ◽  
Dynamic Equilibrium ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Linear Displacement ◽  
Epitaxial Crystallization ◽  
Critical Dose ◽  
Ion Species

AbstractThe transition from ion induced epitaxial crystallization to planar amorphization of a preexisting amorphous layer in silicon has been investigated. The conditions for dynamic equilibrium at the transition were determined for different ion species as a function of dose rate and temperature. The critical dose rate for equilibrium varies exponentially with 1/T, exhibiting an activation energy of ∼1.2 eV. Furthermore, for different ions, the critical dose rate is inversely proportional to the square of the linear displacement density created by individual ions. This second order defect production process and the activation energy, which is characteristic of divacancy dissociation, suggest that the accumulation of divacancies at the amorphous/crystalline interface controls the balance between crystallization and amorphization.

Divacancy control of the balance between ion-beam-induced epitaxial cyrstallization and amorphization in silicon

1988 ◽  
Vol 3 (6) ◽  
pp. 1208-1211 ◽  
Author(s):  
J. Linnros ◽  
R. G. Elliman ◽  
W. L. Brown
Keyword(s):  
Activation Energy ◽  
Temperature Dependence ◽  
Dose Rate ◽  
Dissociation Energy ◽  
Ion Beam ◽  
Ion Bombardment ◽  
Collision Cascade ◽  
Quadratic Dependence ◽  
Ion Species ◽  
Interface Movement

The ion-bombardment-induced reversible movement of a planar amorphous/crystalline interface in silicon has been studied between 100 and 400 °C. The temperature dependence of the ion dose rate at which there is zero interface movement has an activation energy of 1.2 eV, the dissociation energy of divacancies. Scaling of this dose rate for different ion species exhibits a quadratic dependence on the density of displaced atoms in the collision cascade of individual ions, giving further evidence for divacancy control of the interface movement.

Ion Beam Induced Amorphization and Crystallization Processes in Silicon and GaAs

1986 ◽  
Vol 74 ◽  
Author(s):  
R. G. Elliman ◽  
J. S. Williams ◽  
S. T. Johnson ◽  
E. Nygren
Keyword(s):  
Crystal Growth ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Poor Quality ◽  
Layer By Layer ◽  
Epitaxial Crystallization ◽  
Non Linear ◽  
Thickness Layer

AbstractThin amorphous layers in crystalline Si and GaAs substates have been irradiated at selected temperatures with 1.5 MeV Ne+ ions to induce either epitaxial crystallization or amorphization. In Si, such irradiation can induce complete epitaxial crystallization of a 1000 A surface amorphous layer for temperatures typically >200°C whereas, at significantly lower temperatures, layer-by-layer amorphization results. Although epitaxial crystallization can also be stimulated in GaAs by ion irradiation at temperatures >65°C, the process is non-linear with ion dose and results in poor quality crystal growth for amorphous layers greater than a few hundred Angstroms in thickness. Layer-by-layer amorphization has not been observed in GaAs.

Amorphization of Silicon by Ion Irradiation: The Role of the Divacancy

1988 ◽  
Vol 100 ◽  
Author(s):  
R. G. Elliman ◽  
J. Linnros ◽  
W. L. Brown
Keyword(s):  
Activation Energy ◽  
Ion Irradiation ◽  
Amorphous Layer ◽  
Irradiation Temperature ◽  
Defect Production ◽  
Critical Flux ◽  
Defect Annealing ◽  
The Stability ◽  
Arrhenius Expression

ABSTRACTFixed fluence ion irradiation of silicon is shown to produce either defected crystal or amorphous silicon depending on the ion flux employed. The amorphous threshold flux, defined as the minimum flux required to generate a continuous amorphous layer for a fixed fluence irradiation, is measured as a function of irradiation temperature. This critical flux for amorphization is shown to satisfy an Arrhenius expression with a unique activation energy of ∼1.2eV, which corresponds to the migration/dissociation energy of the silicon divacancy. These observations lead to the conclusion that the stability of the silicon divacancy controls the competition between defect production and dynamic defect annealing, and hence the crystalline to amorphous phase transformation.

The effect of annealing environments on the epitaxial recrystallization of ion-beam-amorphized SrTiO3

1992 ◽  
Vol 7 (3) ◽  
pp. 717-724 ◽  
Author(s):  
J. Rankin ◽  
J.C. McCallum ◽  
L.A. Boatner
Keyword(s):  
Activation Energy ◽  
Solid Phase ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Surface Layers ◽  
Time Resolved ◽  
Near Surface ◽  
Thermally Induced ◽  
Stage Process ◽  
Single Constant

Time-resolved reflectivity and Rutherford backscattering spectroscopy were used to investigate the effects of regrowth environments on the thermally induced solid phase epitaxial (SPE) regrowth of amorphous near-surface layers produced by ion implantation of single-crystal SrTiO3. Water vapor in the regrowth atmosphere was found to alter both the apparent rate and activation energy of the SPE regrowth. For relatively dry atmospheres, a single constant regrowth rate is observed at any given temperature, and the activation energy is 1.2 ± 0.1 eV. When the concentration of H2O vapor in the atmosphere is increased, however, the regrowth activation energy effectively decreases to ∼0.95 eV. When regrown in atmospheres containing H2O vapor, the SrTiO3 amorphous layer exhibits two distinct stages of SPE regrowth as compared to the single rate found for dry anneals. This two-stage process apparently results from the diffusion of H/OH from the regrowth atmosphere at the surface of the crystal through the amorphous layer to the regrowing crystalline/amorphous interface.

The Role Of Ion Species On The Adhesion Enhancement Of ION Beam Mixed Fe/Al2O3 Systems

1991 ◽  
Vol 238 ◽  
Author(s):  
J. E. Pawel ◽  
C. J. Mchargue ◽  
L. J. Romana ◽  
L. L. Horton ◽  
J. J. Wert
Keyword(s):  
Interfacial Energy ◽  
Peak Concentration ◽  
Ion Beam ◽  
Scratch Test ◽  
Film Deposition ◽  
Ion Concentration ◽  
Concentration Profiles ◽  
Pull Test ◽  
Ion Species

ABSTRACTThe role of the ion species on the adhesion enhancement of ion beam mixed Fe/Al2O3 systems has been investigated. The ion implantations were carried out after film deposition using Cr (300 keV), Fe (320 keV), or Ni (340 keV) ions. The adhesion of the films was measured by a pull test and a scratch test. While the three types of implantation result in similar ion concentration profiles (with the peak concentration at the interface) and similar damage profiles, the three species were not equally effective in improving the adhesion. The effects are proposed to be due to changes in the interfacial energy resulting from both the damage and the presence of the ion species at the interface.

Ion Beam Induced Epitaxial Crystallization of Single Crystalline 6H-SiC

1993 ◽  
Vol 321 ◽  
Author(s):  
V. Heera ◽  
R. Kögler ◽  
W. Skorupa ◽  
E. Glaser
Keyword(s):  
Surface Layer ◽  
Ion Irradiation ◽  
Ion Beam ◽  
Amorphous Layer ◽  
Single Crystalline ◽  
Epitaxial Crystallization ◽  
Amorphous Surface ◽  
20 Nm ◽  
First Time

ABSTRACTFor the first time, ion beam induced epitaxial crystallization (IBIEC) has been found in SiC. The effect of 300 keV Si+ irradiation through an amorphous surface layer in single crystalline 6H-SiC at 477+5°C has been investigated by RBS/C and XTEM. A shrinkage of the amorphous layer was found after ion irradiation at this temperature which is caused by both an ion dose independent thermal regrowth of about 20 nm and an additional ion beam induced epitaxial crystallization with a rate of about 1.5 nm/ 1016 cm−2.

Kinetics, Microstructure And Mechanisms of Ion Beam Induced Epitaxial Crystallization of Semiconductors.

1985 ◽  
Vol 51 ◽  
Author(s):  
R.G. Elliman ◽  
J.S. Williams ◽  
D.M. Maher ◽  
W.L. Brown
Keyword(s):  
Activation Energy ◽  
Simple Model ◽  
Epitaxial Growth ◽  
Ion Beam ◽  
The Other ◽  
Thermally Induced ◽  
Substrate Orientation ◽  
Epitaxial Crystallization ◽  
Temperature Range ◽  
Other Hand

ABSTRACTIon-beam induced epitaxy is shown to be essentially athermal over the temperature range 200-400°C, and to exhibit no dependence on substrate orientation and little dependence on doping in this regime. On the other hand, the formation and propagation of defects during growth and the interaction of the advancing crystal-amorphous interface with implanted impurities is essentially identical for both thermally induced and ion-beam induced epitaxy. These observations lead to a simple model for ion-beam induced epitaxial crystallization in which epitaxial growth is nucleated by defects generated at, or near, the crystal-amorphous interface by the ion beam. Comparisons of ion-beam induced epitaxy and thermally induced epitaxy suggest that the 2.7 eV activation energy associated with the latter process is dominated by a 2.0 eV nucleation step.

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