Si amorphization by focused ion beam milling: Point defect model with dynamic BCA simulation and experimental...

Area of Science:

• Materials Science
• Computational Physics
• Nanotechnology

Background:

• Focused ion beam (FIB) milling is essential for transmission electron microscopy (TEM) sample preparation.
• Gallium (Ga) FIB processing of crystalline silicon (c-Si) creates an amorphous surface layer, impacting analysis.
• Minimizing amorphization requires accurate prediction of the amorphous layer thickness via simulation.

Purpose of the Study:

• To introduce and validate a novel simulation approach for predicting FIB-induced amorphization in silicon.
• To enhance the accuracy of amorphous layer thickness prediction for optimized FIB milling recipes.

Main Methods:

• Developed a Point Defect Density approach integrated into dynamic Binary Collision Approximation (BCA) simulations.
• Incorporated dynamic ion-solid interactions into the BCA model for enhanced realism.
• Validated simulation predictions against experimental data from transmission electron microscopy (TEM) studies.

Main Results:

• The Point Defect Density approach within dynamic BCA simulations accurately predicts the thickness of the amorphous layer formed on c-Si by FIB milling.
• Simulation results show strong consistency with experimentally measured amorphous layer thicknesses.
• The method effectively models ion-solid interactions at a scale relevant to FIB processes.

Conclusions:

• The Point Defect Density approach offers a computationally viable and accurate method for predicting FIB-induced amorphization in silicon.
• This simulation technique can guide the optimization of FIB milling parameters to minimize surface amorphization.
• Accurate prediction of amorphous layer thickness is vital for reliable TEM analysis of semiconductor materials.