Picosecond Acoustic Analysis for Nanomaterials

Narciso Gambacorti, Nanocharacterization Program Manager at CEA-Leti talks to AZoNano about Picosecond Acoustic Analysis for Nanotechnology.

Please can you provide a brief introduction to CEA-Leti?

CEA-Leti is focused on innovation and value creation through technology transfer to industry. We specialize in nanoelectronics, and micro- and nanotechnologies and their applications in wireless devices & systems, and biology & healthcare, as well as in microsensors, photonic devices, imagers and security solutions.

Leti operates 8,000m² of state-of-the-art clean room space on 200mm and 300mm wafer platforms. It employs 1,700 scientists and engineers including 240 Ph.D. students and 200 assignees from partner companies. Leti owns more than 1,880 patent families.

What will the new joint-development program between CEA-Leti and Menapic involve and how will it benefit both participants?

Menapic’s colored picosecond acoustics (APiC) technology is an innovative tool for characterizing the mechanical properties of thin films. The JDP is designed to extend the use of this technology in new markets for Menapic, including the microelectronics industry and thin-materials analysis.

This new equipment will complete Leti’s unique offer in terms of materials analysis available in our world-class nanocharacterization platform. Menapic’s experience in materials analysis and colored picosecond acoustics technology, in particular, will accelerate the introduction of this technique at Leti.

What do you aim to achieve from applying coloured picosecond acoustics to material analysis?

The technique will be complementary to other techniques available with the Leti Nanocharacterization Platform (PFNC). This will accelerate materials development for micro-nano technologies; for example: thickness of opaque materials, buried interface characterization, and mechanical properties of thin films.

What will this technique involve?

APiC is an optical technique that uses pulsed laser excitation to generate an acoustic wave in the structure. The propagation of the acoustic wave depends on the materials’ properties and is probed by another laser pulse.

Can you discuss the advantages to the Menapic’s coloured picosecond acoustics (APiC) technology?

This technique is non-destructive and spatially resolved (~10 µm). Also, the substrate does not affect the measurement of Young’s modulus of the films. It can also be used to measure the thickness of opaque materials, where other non-destructive techniques like ellipsometry are blind.

How does this technology characterize each layer of nano-scaled structures?

The acoustic wave propagation is affected by each interface. In particular, the APiC measurement technology reproduces the principle of sonar in nanoscaled structures: a pulsed laser source is used to generate acoustic waves in the stack of thin films.

The analysis of the acoustic pulse propagation in the structure enables the characterization of each layer of the stack.

How will the JDP extend the use of this technology in microelectronics and thin-material analysis?

A demo tool will be installed in the PFNC. This system will be used to analyze the more advanced materials/filmstack developed in Leti’s advanced semiconductor R&D facility.

How does coloured picosecond acoustics help with scaling of processes for integrated electronics?

APiC will accelerate materials development by answering questions that are more difficult or even impossible to answer with other characterization techniques.

What will this new equipment offer the end-user?

This equipment will offer a new way to characterize the mechanical properties of thin films and a new way to gain information on buried structures that are not easily accessible with other non-destructive techniques.

How can you see this technology accelerating the application of this technique in the microelectronics and thin-layer industry?

The presence of the APiC on the PFNC will allow us to test and use this equipment and also to compare the results with results obtained using complementary techniques available on the platform. All this will speed-up the introduction of this technique to answer technological questions.

How do you plan on developing this technology and technique further to expand its field of application?

The APiC system will be part of the PFNC, which is also open to different end users working on photonics or nano-biology.

Where can we find further information?

For further information please visit Menapic’s website.

About Narciso Gambacorti

Narciso Gambacorti received a degree in physics in 1991 from the University of Rome La Sapienza. From 1992 to 1997, he was a researcher at National Research Council (CNR) institutes in Italy (MASPEC-Parma, ICMAT-Rome), where he worked on the characterization of gallium arsenide (GaAs) and indium phosphide (InP) advanced heterostructures with different techniques.

Between 1997 and 2008, he worked as a Senior Metrology Research Scientist for THERMAWAVE and KLA-Tencor Corp. He joined CEA-Leti on the MINATEC campus in Grenoble, France, in 2009 as Nanocharacterization Program Manager.

Narciso is in charge of building research programs with industrial and institutional partners in the field of in-line metrology and off-line physical/chemical characterization.