Cornell-led team images atomic-scale defects in computer chips
A Cornell-led research team imaged atomic-scale defects in computer chips for the first time using high-resolution 3D electron microscopy. The team collaborated with TSMC and Advanced Semiconductor Materials on the study.
The findings reveal previously invisible defects that can degrade chip performance in modern transistors, which have channels only 15 to 18 atoms wide. The imaging technique provides a characterization tool for debugging devices under development and could reshape how the semiconductor industry diagnoses flaws.
The study was published in Nature Communications and details interface roughness defects that lead researcher Shake Karapetyan dubbed “mouse bites.” These irregular atomic features occur along the walls of transistor channels. The technique uses multislice electron ptychography to offer detail no previous method could achieve at this scale.
The team used an electron microscope pixel array detector to capture scattering patterns through prototype gate-all-around transistors. The detector holds a Guinness World Record for highest-resolution images. The technique reconstructs 3D images with sub-ångström lateral resolution and nanometer-scale depth.
David Muller, who led the project, stated there is no other way to see these defects at the atomic level. Muller is the Samuel B. Eckert Professor of Engineering at Cornell’s College of Engineering. He stated the tool will be important for debugging and fault-finding of computer chips.
The research found that the top and bottom interfaces of transistor channels exhibit different roughness profiles. These profiles reflect different processing conditions, which could help optimize hundreds of fabrication steps. The technique may eventually apply to devices ranging from smartphones to AI data centers and quantum computers.
Muller and ASM vice president of technology Glen Wilk first collaborated at Bell Labs in the late 1990s. They pioneered the use of hafnium oxide as a gate material, which became an industry standard in the early 2000s. Twenty-five years later, supported by TSMC’s corporate analysis lab, they reunited to apply ptychography to modern device structures.
The research team includes collaborators from TSMC and Advanced Semiconductor Materials. The study addresses unsolved challenges in atomic-level structural control for advanced computing devices.