Transcript Ion Implantation - Universitetet i oslo

Ion Implantation
A summary to aid you in studying for
the exam
Agenda
• Quick recap
• Stopping
• Projected range
• Implantation damage
• Advantages/disadvantages
Setup
•
Figure 1: From http://www.spirecorp.com/spire-biomedical/surface-modification-technology/ion-implantation.php
Stopping
• Coulomb scattering
• Two hard spheres scattering elastically
• Energy loss dependencies
Nuclear stopping
Projected range
Deviations
Deviations continued
Channeling
• Less nuclear stopping and low electron densities
• Produces a tail in the implant distribution
• Largest effect when the incident ion is small
• Avoided by using an implant tilt or
preamorphizing.
Lattice damage
• Bonds broken.
• Critical dose dependent on energy, species
and temperature.
• More damage further in due to nuclear
stopping becoming the dominant mechanism
• Anneal used to decrease defect density and to
activate implanted species
Shallow junctions
• Low energy difficult due to beam broadening
• Very low energy implants usually performed
using molecules
• Thermal electrons
Advantages and difficulties
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Quite controllable
Low amount of impurities
Lattice damage
Shallow junctions
Channeling