1. Ion Implantation A summary to aid you in studying for the exam

2. Agenda Quick recap Stopping Projected range Implantation damage Advantages/disadvantages

3. Setup Figure 1: From http://www.spirecorp.com/spire-biomedical/surface-modification-technology/ion-implantation.php

4. Stopping Coulomb scattering Two hard spheres scattering elastically Energy loss dependencies

6. Nuclear stopping

7. Projected range

8. Deviations

9. Deviations continued

10. 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.

11. 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

12. Shallow junctions Low energy difficult due to beam broadening Very low energy implants usually performed using molecules Thermal electrons

13. Advantages and difficulties Quite controllable Low amount of impurities Lattice damage Shallow junctions Channeling