Implantation srim trim
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Transcript of Implantation srim trim
ImplantationIntroduction, Principle,
SRIM & TRIM simulation, Thermal Spike Model and Observations from SRIM
K. Kamalakkannan,Junior Research Fellow, Ion Beam Research LabDepartment of Nuclear Physics University of Madras, [email protected]
Department of Nuclear Physics
Introduction All the electronic equipment needs Semiconducting materials (p-n type). Doping of impurities (carriers) can be processed by two ways- Diffusion and
Implantation. Diffusion is limiting process due to saturation limit and so, we can’t make high
concentrated carriers. To overcome the diffusion issues of dopants & activation of dopants in material- ion
implantation or ion irradiation is the best. In general using particle accelerators to shoot energetic ions on a material is the basic
process of implantation and irradiation. Ion implantation is a variety of ion irradiation, as is swift heavy ions irradiation from
particle accelerators with very high energies induces ion tracks.
Department of Nuclear Physics
Ion Implantation- Introduction Ion implantation- a materials engineering process by which ions of a material are
accelerated in an electrical field and impacted into a solid. This process is used to change the physics, chemical and/or electrical properties of
the solid- cause many chemical and physical changes in the target by transferring their energy and momentum to the electrons and atomic nuclei of the target material- causes a structural change, in that the crystal structure of the target.
Major components are,1. Ion source2. Accelerator3. Target chamber
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Ion Implanter
Implantation
Structuring
Thin FilmDeposition
Ex: Simulation of B ions in SiC 300 keV
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Important parameters and Typical values
E
q
I
A
j
Ion Energy (eV)
Ion Charge Number
Ion Current (A)
A Angle of IncidenceE,q,I(cm2)
(cm-2s-1)
Irradiated Area
Ion Flux
(cm-2)Ion Fluence
Remark: “Dose” is often used rather than “Fluence”(although “Dose” should be a volume energy density)
j t
j I
qeA
(10 to 500 keV)
(10 μA to ~30 mA)(60 to 70)
Ion source: Any element including gas in whole periodic table can be chooseTarget: Any target matrix can be choose.
Department of Nuclear Physics
Ion- Solid interactions
Multiple collision With electrons
E= Energy of ions m1, Z1 and m2, Z2= Mass No., At. No. of Incident ions and Target material Rp= Range of ions
When energetic ions passes through matter, it looses its energy in two ways,
1. Electronic energy loss due to inelastic collision with electrons(Se) [Electronic stopping]
2. Nuclear energy loss due to elastic collision with atoms of the solid(Sn) [Nuclear stopping]
Electronic stopping- Dominant at higher energies (tens of MeV & more)- Swift Heavy ion irradiation (SHI)
Nuclear stopping- Dominant at low energies (tens of keV to MeV)
Department of Nuclear Physics
Implantation Simulations- SRIM and TRIM
SRIM- The Stopping and Range of Ions in Matter - Group of programs which calculate the stopping and range of ions (up to 2 GeV/amu) into matter using a quantum mechanical treatment of ion-atom collisions.
TRIM- The Transport of Ions in Matter - Most comprehensive program, accept complex targets made of compound
materials with up to eight layers, each of different materials. It calculate all kinetic phenomena associated with the ion's energy loss: target damage, sputtering, ionization, and phonon production.
Based on a Monte-Carlo calculation which follows the ion into the target, making detailed calculations of the energy transferred to every target atom collision. (multi-layer complex targets)
Developed by J. F. Ziegler and J. P. Biersack
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SRIM- Main Page SRIM and TRIM main menu- shown Can select to use Stopping/Range Table and/or to use TRIM simulation for given Ion with given Energy.
For SRIM calculations
For TRIM calculations
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Stopping and Range Table Calculation
Suitable Ions from periodic table
Common compounds- List of all materials
SRIM output table button Stopping power units- MeV/(mg/cm2), eV/Angstrom, keV/ um, keV/(ug/cm2), MeV/mm, etc.
Energy Low to High
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SRIM Output TableSRIM output Table for Hydrogen ion in SiC Target
Stopping power unit (MeV/ (mg/cm2)
Lateral stragglingLongitudinal stragglingProjected range
Electronic and nuclear stopping powersIon energy
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SRIM calculations: Energy Loss- Stopping powers Stopping powers Sn= dE/dx (Differential energy loss per unit length) Low energy ions <2MeV – elastic collision – nuclear energy loss High energy ions > 2MeV – Inelastic collision – electronic energy loss - SHI. Electronic stopping- (Electronic energy loss) Interaction of heavily charged ions
with electrons of the target material through Coulomb forces, produce track of ionization and highly kinetic electrons along the path of the primary ion - latent track (Se>Sth) – Sth depends on the material.
This Electronic stopping forms huge defects (defect clusters, dislocation loop disordered lattice, amorphous etc.)
Nuclear Energy loss- Due to elastic collision at lower energies dominant nuclear stopping. This Causes damage and dislocation of nuclei from their lattice sites due to elastic collisions.
Always produce lattice defects(Interstitial atoms, anionic or cationic vacancies)
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Electronic and Nuclear stopping power- Ex: Aluminum
SRIM prediction of electronic and nuclear stopping power of Al ion in different ion energies.
Nuclear stopping power is mostly happened for low energy implantation. The lower value of nuclear stopping power is causes the less defects because the higher nuclear stopping power leads atomic displacements.
Department of Nuclear Physics
Thermal Spike Model The energy-loss mechanism of the projectile-ion leads to electronic and atomic collision-cascades This model replaces the complex process of the atomic collision-cascades by an abrupt temperature
rise in an infinitesimal cylindrical volume around the ion trajectory at the time-of-passage t = 0.
Basic steps of thermal-spike model.
(a) Undisturbed solid at temperature T0. (b) At the time-of-passage the tem perature within a
small cylinder rises rapidly to a much higher temperature T »T0.
(c) After the passage of the ion, defects are thermally created while the thermal energy gradually dif fuses away radially from the ion trajectory.
(d) Remaining are "frozen" defects.
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TRIM Input page
Suitable Ion, Energy and Angle
Quick or full calculation of table
Common compounds- List of all materials
Outputs- ion range, Backscattered, Transmitted,Sputtered ions and Collision Details
Ion fluence
Target layers and Target thickness
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TRIM Simulation PageTRIM simulation table for B (10 keV) in SiO2/Si
bi-layerIon type, Energy and Angle
XY Simulation graph
Distributions- range, Phonons, Ionization, Energy to recoils, Damage events, Sputtering yields and
Collision details
Damage calculation type- Kinchin- Pease, Full cascades and sputtering
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Observations from SRIM and TRIM
Ion Range (Rp)= Range of ionEx: Boron 100 keV in SiC (Rp= 2010 Å)
XY Ions SimulationEx: Boron 100 keV in SiC
Damage events
Ex: Boron 100 keV in SiC
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Observations from SRIM and TRIM
Recoil EnergyEx: Al 300 keV in SiC
Energy Loss due to ionizationEx: Al 300 keV in SiC
Also,3D views of ion damages, Range of ions, Recoil energy, Phonon and Lateral range distribution XY ions simulations- Lateral, Longitudinal view and Vacancies can be calculated
Thank You