Controlling Thermal Conductivity of Amorphous SiO Films through Structural Engineering Utilizing Single Crystal...

Area of Science:

• Materials Science
• Condensed Matter Physics
• Nanotechnology

Background:

• Developing insulating thin films with low thermal conductivity (κ) and high dielectric breakdown strength is crucial for advanced electronics packaging and power electronics.
• Silica glass (SiO2) offers high dielectric strength but typically has higher κ than multicomponent glasses.
• Optimizing κ in SiO2 films is key to enhancing thermal management in electronic devices.

Purpose of the Study:

• To investigate methods for reducing thermal conductivity (κ) in silica glass (SiO2) thin films.
• To understand the relationship between atomic ordering, substrate interactions, and thermal transport in SiO2 films.
• To enable the design of novel insulating materials for demanding electronic applications.

Main Methods:

• Fabrication of SiO2 thin films with controlled atomic ordering.
• Utilizing substrate surface atom constraints to influence film structure.
• Characterization of atomic ordering using grazing incidence X-ray total scattering.
• Measurement of thermal conductivity (κ) in the fabricated films.

Main Results:

• A significant, systematic decrease in thermal conductivity (κ) was achieved by shortening intermediate ordering distances.
• Stronger constraints from substrate surface atoms led to reduced κ.
• SiO2 films on Si substrates exhibited the most substantial κ reduction, reaching one-third of the bulk value.
• Changes in atomic ordering were confirmed by shifts in the main halo observed via X-ray scattering.

Conclusions:

• Substrate-induced control over atomic ordering is an effective strategy for minimizing thermal conductivity (κ) in SiO2 thin films.
• This provides a pathway for designing advanced insulating materials with tailored thermal properties for electronics.
• The findings contribute to a deeper understanding of thermal transport mechanisms in amorphous thin films.