CEA-LETI develops leading edge manufacturing processes for the advanced technology nodes in nano-electronics, and effectively transfers this knowledge to the industry. Cool-Cube® is a challenging and promising option developed at LETI to build integrated 3d components. This technology, as well as other key enabling technologies, requires new annealing processes. Tools manufacturers are developing nanosecond annealing lasers that could solve this issue: the short laser pulse raises the temperature of the surface up to the melting point of silicon while the underlying layers of transistors keep cool. Major difficulties must be overcome with the laser, that will be addressed in this thesis: first, we must understand the physical mechanisms of this fast process: diffusion of chemical species, phase change, evolution of the defects in the crystal. On the other hand, a tight prediction and control of the temperature necessitates to understand how and where the laser transfers energy to the material, where and when the heat diffuses in the different layers of the 3d stacking. Design rules on the geometry and will have to be provided to ensure that the process works and to optimize it for industrial applications. This thesis will be based on the numerical modelling of the process and guided by experimental results acquired thanks to the collaboration between Leti and the tool manufacturers.

This position is open until it is filled.

Department: Département Composants Silicium (LETI)
Laboratory: Laboratoire de Simulation et Modélisation
Start Date: 01-09-2015
ECA Code: SL-DRT-15-0752
Contact: benoit.mathieu<στο>cea.fr