Erweiterung der zeitlichen und räumlichen Auflösung für die Abbildung von Gitterdynamiken mittels FFXDM am ID01 (Ex-FFXDM)

Das übergeordnete Ziel unseres Projekts besteht darin, tiefere Einblicke in Prozesse und Gitterdynamiken in einkristallinen Materialien und epitaktischen Systemen zu gewinnen, die die Grundlage der modernen Halbleitertechnologie und elektronischer Bauelemente bilden. Damit wollen wir anwendungsbezogene Fragen zum Energiefluss in akustischen Oberflächenwellen, zur Wärmeableitung in Halbleiterlasern und der Leistungselektronik sowie zur Konsistenz und Zuverlässigkeit der ferroelektrischen Oxidelektronik angehen. Wir streben aber auch ein besseres Verständnis grundlegender kristalliner Materialprozesse an, darunter phononische und elektronische Phänomene, temperaturinduzierte Kristallisation, Spannungsrelaxation und Kristallwachstum.

Um dies zu erreichen, schlagen wir vor, die ID01-Mikrodiffraktions-Bildgebungsstrahlführung mit modernster Instrumentierung auszustatten, um zeitaufgelöste Vollfeld-Röntgendiffraktionsmikroskopie (FF-XDM) zur Abbildung der Gitterdynamik sowohl im Volumen als auch an der Oberfläche kristalliner Materialien vollständig zu ermöglichen. Dieser Ansatz wird die direkte Röntgenbildgebung von Gittereigenschaften auf bisher unerreichten Längen- und Zeitskalen ermöglichen.

Expanding time and spatial resolution for imaging of lattice dynamics by FFXDM at ID01 (Ex-FFXDM)

The overall objective of our project is to enable deeper insights into processes and lattice dynamics in single-crystalline materials and epitaxial systems, foundational to modern semiconductor technology and electronic devices. We thereby aim to address applied questions concerning the energy flow in surface acoustic waves, heat dissipation in semiconductor lasers and power electronics, and the consistency and reliability of ferroelectric oxide electronics. But we also seek to advance our understanding of fundamental crystalline material processes, including phononic and electronic phenomena, temperature-induced crystallization, strain relaxation, and crystal growth.
To achieve this, we propose equipping the ID01 microdiffraction imaging beamline with advanced instrumentation to fully enable time-resolved Full-Field X-ray Diffraction Microscopy (FF-XDM) for imaging lattice dynamics in both bulk and surface regions of crystalline materials. This approach will enable direct X-ray imaging of lattice properties at unprecedented length and time scales.
In terms of time resolution, we are targeting two distinct categories:
i) the imaging of repetitive processes taking place on time scales of picoseconds or longer,
ii) real-time imaging of stochastic events, which we aim to capture at the millisecond level.
In the latter case, the detectable signal intensity on the X-ray sensor is the main factor limiting the time-resolution. Therefore, real-time imaging benefits from all developments enhancing the signal, such as are planned in this project.
A key tool to that end are multilayer Laue lenses (MLLs), which offer higher numerical aperture, resulting in unmatched magnification and efficiency compared to traditional X-ray optics, such as Fresnel Zone Plates (FZPs) or Compound Refractive Lenses (CRLs). Already a very promising novel focusing device, it turns out that the MLLs specific characteristics, namely to be a “thin lens” as compared to CRLs or to offer angular separation of diffraction orders (as compared to FZPs) makes them superior to all competition when used in dark field imaging mode, e.g. in FF-XDM. Our goal is to implement these novel MLL optics at the world-wide unique FF-XDM setup at ID01/ESRF, enabling a tenfold improvement in spatial resolution and useful flux. The latter translates directly in increased time resolution and faster measurements.