Nearfield Instruments has introduced what it claims is the first in-line, non-destructive subsurface metrology system for advanced semiconductor manufacturing.
Called Audira, the tool complements current metrology offerings providing accurate and non-destructive nanometer-level measurements through opaque layers of advanced leading-edge node devices. These measurements of buried features and defects such as voids in advanced memory and logic devices.
Nearfield said Audira will complement transmission electronic microscopy (TEM) and critical dimension-scanning electron microscopy (CD_SEM) for subsurface process control measurements.
The technology combines an acoustic microscopy technique with its own atomic force microscopy (AFM) that is used to listen to soundwaves coming through the wafer layers. The wave interacts with all the transitions and surfaces within the device and reflects information back. The pattern is a reflected wave and the time of arrival contains data about the structure below the surface. Audira scans the die with each step as small as several tenths of a nanometer and the data is translated into a pattern of underlying layers for measurement of subsurface features.
Additionally, the software can measure shallow features through the surface using the AFM probe that can measure to reveal details about the structure below. Nearfield said it plans to develop a recipe for when to use acoustics and at what frequency depending on the customer. The technology is slated to be available in the second quarter of 2024.
