Primary Radiation Damage in a Strain-Engineering-Based SiGe/Si Heterostructure: A Molecular Dynamics Simulation

Area of Science:

• Materials Science
• Semiconductor Physics
• Computational Physics

Background:

• Space-borne electronics face radiation damage from high-energy particles.
• Silicon-Germanium (SiGe) heterostructures are crucial for advanced electronics but susceptible to displacement damage.

Purpose of the Study:

• Investigate primary radiation damage in strain-engineered SiGe/Si heterostructures.
• Analyze defect evolution under independent and overlapping collision cascades.

Main Methods:

• Molecular dynamics simulations were employed.
• Simulations considered primary knock-on atoms (PKAs) of Silicon (Si) and Germanium (Ge) at 1, 3, and 5 keV.
• Two cascade scenarios: independent and overlapping.

Main Results:

• 3 keV Ge PKAs generated the most point defects at the SiGe/Si heterointerface.
• Frenkel pair defects increased initially then annihilated, while antisites accumulated over cascades.
• Defect distribution was influenced by the melting region and superimposed in overlapping cascades.

Conclusions:

• Understanding defect evolution and overlapping effects is key for SiGe/Si heterostructures.
• Findings inform radiation-hardening techniques for SiGe-based space electronics.