High-precision deformation mapping in finFET transistors with two nanometre spatial resolution by precession electron...

Area of Science:

• Materials Science
• Solid State Physics
• Nanotechnology

Background:

• Silicon-germanium (Si/SiGe) heterostructures are crucial for advanced semiconductor devices.
• Understanding strain distribution is vital for optimizing performance in finFETs and other microelectronic components.
• Accurate deformation measurement techniques are needed for state-of-the-art electronic device characterization.

Purpose of the Study:

• To systematically measure and map deformation in Si/SiGe blanket films and patterned finFET structures.
• To validate the precision and spatial resolution of precession electron diffraction for deformation analysis.
• To investigate the strain relaxation behavior in patterned Si/SiGe fin structures.

Main Methods:

• Utilized precession electron diffraction to obtain deformation maps with 2.0 nm spatial resolution and ±0.025% precision.
• Validated precession diffraction measurements against energy-dispersive X-ray spectrometry, X-ray diffraction, and finite element simulations.
• Analyzed deformation in both blanket Si/SiGe films and patterned finFET test structures on silicon-on-insulator wafers.

Main Results:

• Demonstrated high-resolution (2.0 nm) and high-precision (±0.025%) deformation mapping using precession electron diffraction.
• Confirmed that blanket Si/SiGe films exhibit biaxial strain.
• Showed that patterned Si/SiGe fin structures are fully relaxed in the investigated crystallographic planes.

Conclusions:

• Precession electron diffraction is a viable and precise technique for mapping deformation in semiconductor materials.
• Patterned fin structures exhibit significant strain relaxation compared to blanket films.
• This technique provides valuable insights for the development of advanced electronic devices.