1. Karolina Danuta Pągowska
Soltan Institute for Nuclear Studies
Compositional dependence of damage buildup in Ar - ion bombarded AlxGa1-xN
Karolina Danuta Pągowska

2. Outline
1. Energy loss of ions in solids, collision cascade
2. Ion implanter
3. FET
4. RBS and channeling
5. Channeling spectra for ion bombarded GaN
6. Multi-step damage accumulation in irradiated crystals
7. Summary

3. Energy - Depth – Relation for 1.5 MeV He–ions in Si
Rp = 5.21 µm
Depth/ µm

4. Energy loss of ions in solids
He ions
Ar ions
Energy loss
He ions
Ar ions
Ionization
dEe/dx
Displace-
ments
dEn/dx
Ion velocity ~ (Energy)1/2

5. Collision cascade

6. Ion implanter Target chamber Wobbler Magnetic lenses Accelerator
Magnetic separator
Ion source
Extraction

7. Ion implantation in compound semiconductors and their heterostructures in usually performed for:
Doping
Insulating region formation (patterned implantation)
Mask
Ion beam
Sample

8. Field – Effect Transistor (FET)
Si substrate
Ion beam
Mask

9. SOI – Silicon On Insulator
SiO2 Si

10. Principles of Rutherford Backscattering Spectrometry
Energy
Depth x0
Yield x0
Detector
- O
- Si
4He, 2 MeV x0 Si
SiO2

11. Ion channeling

12. Defect analysis using ion channeling
Short summary of HRXRD superlattice analysis

13. Channeling spectra for ion implanted GaN

14. Experiment and simulation

15. Distribution of displacement atoms

16. Schematic representation of the MSDA model
Structure A
Structure B
Structure C
A  B
B  C
Low fluence
Stage 1
Medium fluence
Stage 2
High fluence
Stage 3 a b c

17. Simulation multi-step accumulation

18. Three-step accumulation
For GaN
fd1=6
sig1=0.77
fd2=68.5
sig2=0.0398
x2=12.5
fd3=100
sig3=0.008
x3=400

19. Three-step accumulation

20. Two-step accumulation
For AlGaN
fd1=6
sig1=0.86
fd2=54
sig2=0.015
x2=5

21. Two-step accumulation

22. For AlN fd1=7 sig1=0.245 fd2=63.5 sig2=0.02 x2=10
Two-step accumulation
For AlN fd1=7 sig1=0.245 fd2=63.5 sig2=0.02 x2=10

23. Two-step accumulation

24. Summary
GaN
Three-step accumulation
AlGaN
Two-step accumulation
AlN

25. Thanks for attention