CEA-Leti has turned strain mapping into a practical characterization service for chipmakers, using transmission electron microscopy (TEM) and precession electron diffraction (PED) to measure local lattice deformation at the nanometre scale. The work matters because the performance of advanced microelectronic devices depends heavily on efficient charge transport, which is strongly influenced by crystal-lattice strain. By deliberately stretching or compressing the lattice, strain engineering can speed electron flow and improve processor performance and power efficiency, even with changes in lattice spacing of only a fraction of a percent.

The service begins with ultra-thin lamellae, about 80 nm thick, cut from a chip cross-section using focused ion beam (FIB) milling. These specimens are then inserted into a TEM fitted with a PED module. Unlike ordinary electron diffraction, where a fixed beam angle can produce complex patterns because of dynamic scattering, PED rotates the beam in a conical sweep and captures diffraction data across dozens of orientations. That produces cleaner, more complete patterns that can be converted into strain maps.

CEA-Leti says the method can deliver 1 nm spatial resolution with about 0.02% precision, putting the lab among the world leaders in nanoscale metrology. The workflow has also been simplified and accelerated to improve throughput and shorten turnaround times for characterization requests. Three TEMs are now configured for PED measurements, increasing sample capacity and making the service available to more qualified microscopists.

Bernier stressed that the platform was made possible by the combined expertise of the team, highlighting the link between fundamental research and application-driven engineering. That collaboration helped transform an experimental technique into a routine industrial service for measuring material deformation in cutting-edge devices.

​​​​​​The performance of advanced microelectronic devices depends especially on the efficient transport of electrical charges. These transport properties are strongly related to deformation of the crystal lattice.

Strain engineering, which involves deliberately stretching or compressing a crystal lattice, is used to boost the speed of electron flow in a device. Even a fraction of percent change in lattice spacing can translate into faster and more power-efficient processors. That is why at CEA-Leti we have been working in recent years on the local and quantitative measurement of material deformations, which are at the heart of today’s cutting-edge devices.​​​​

CEA‑Leti's strain‑mapping service uses transmission electron microscopy (TEM) to carry out precession electron diffraction (PED). In ordinary electron diffraction the beam hits the crystal at a fixed angle, often producing complex patterns because of dynamic scattering. PED solves that by rotating the beam in a conical sweep, recording a more complete diffraction pattern over dozens of orientations. The result is higher-quality diffraction data that can be turned into strain maps.

The workflow starts with ultra‑thin lamellae—cross‑sections of a chip that are roughly 80 nm thick— prepared using focused ion beam (FIB) milling.

Once the specimen is ready, it is inserted into a TEM microscope equipped with a PED module. Scanning diffraction allows the lab to measure the lattice parameters of the crystal with high spatial resolution in different regions of a device.

The technique delivers strain maps with 1 nm spatial resolution and ~ 0.02 % precision, which places CEA-Leti among the world's leaders in nanoscale metrology.

The technique has been simplified and accelerated where possible to enable higher throughput and make better use of the instruments. The result is a faster turnaround time for characterization requests.

Three TEMs are now equipped to perform PED measurements, allowing CEA-Leti to handle a larger volume of samples and making the service accessible to more qualified microscopists.

The project didn't happen in isolation. Bernier​​ emphasizes the combined expertise of the team members that made it possible:

That partnership between fundamental research and application‑driven engineering helped turn an experimental methodology into a practical, routine characterization service. ​