Raman-converted Kilowatt-class ultrafast laser Solutions for microexplosion-based Silicon transformations and new 3D manufacturing technologies – KiSS
Tightly focused ultrashort laser pulses allow confined micro-explosions in matter that lead to strongly non-equilibrium conditions with extreme pressures (> 10 TPa) and temperatures (>10^5 K) i.e. well beyond those that can be achieved by other techniques. Recently, this has made possible breakthrough in Material Sciences with table-top demonstrations of unprecedented solid transformations into super-dense crystalline phases exhibiting unique properties. This research also encompasses current industrial processes such as laser machining because the same local dynamic compression conditions can be used to carve micro-channels and create any 3D structures beneath the surface of solids.
However, all these advances remain so far limited to transparent wide bandgap dielectrics. Attempts to translate the micro-explosion regimes in bulk silicon have failed because of nonlinear processes that strongly limit the achievable localization of high-power infrared radiation within narrow gap materials. By joint efforts on the investigation of the material response to new interaction schemes and the development of flexible high-power laser solutions in the short-wave infrared domain of the spectrum, KiSS aims at accessing unprecedented micro-explosion conditions inside silicon.
To achieve these challenging objectives, the project KiSS will capitalize on the advent of high-flexibility kW-class ultrafast lasers and demonstrate efficient Raman conversion in single-crystal diamond. On this basis we aim at developing >100W-class ultrafast laser systems emitting in the transparency domain of silicon (1420 nm). A unique feature with the proposed technology is high versatility at the highest power levels in this spectral region. The implemented solution will integrate intra- and extra-cavity beam shaping/control technologies so that the spatio-temporal characteristics of the pulses, delivered at high repetition rates, can be precisely adjusted (on-demand) to meet the severe requirements identified for 3D processing inside semiconductors.
On the front of interaction studies, a new concept behind KiSS is crossed-beam laser geometry to enhance conditions inside matter. Supported by preliminary results, we propose experimental developments in which tightly focused counter-propagating pulses contribute to the interaction. Tight control of synchronizations and beam characteristics of each individual contributing pulse must provide new degrees of freedom to enhance energy densities inside materials. The validity of the concept will be demonstrated by ultrafast study of unprecedented micro-explosion conditions achieved deep inside silicon.
The overall proposed developments must lead to a practical solution with large volume processing capabilities. The expected final demonstrator, unique at the international level, will open new and exciting opportunities for generalized explorations of the matter under laser-driven micro-explosions. This will be supported by a collaborative work with internationally recognized experts on these questions (Australian National University) in which structural diagnostics of cubic millimeter processed silicon will become possible. At long term, the controlled synthesis of new dense phases of silicon will have an extraordinary impact in future technologies. However, we expect also immediate industrial relevance of the developed high-throughput manufacturing technology. This will be shown by the first direct writing demonstrations of microfluidic cooling circuits inside silicon chips.
Furthermore, there is a rapidly growing usage of infrared technologies in many domains (bio-imaging, data communication and processing, …). The ideas behind this proposal will require infrared developments for broadband manipulations and novel infrared diagnostics. For these reasons, KiSS should be beneficial not only for breakthrough in manufacturing technologies but also for a wide range of scientific and technological domains.
Monsieur David GROJO (Centre National de la Recherche Scientifique Délégation Provence et Corse / Laboratoire lasers, plasmas et procédés photoniques)
The author of this summary is the project coordinator, who is responsible for the content of this summary. The ANR declines any responsibility as for its contents.
CNRS DR12 / LP3 Centre National de la Recherche Scientifique Délégation Provence et Corse / Laboratoire lasers, plasmas et procédés photoniques
IFSW Institut für Strahlwerkzeuge - Universitat Stuttgart
Help of the ANR 628,530 euros
Beginning and duration of the scientific project: March 2023 - 36 Months