CoolCube is a sequential 3D integration concept proposed by CEA Leti, France . The two features combined led to the concept name: the lowered temperature upper-level fabrication methods (“COOL”) and the third dimension of 3D integration (“CUBE”). IBM, Qualcomm and STMicroelectronics are among Leti’s partners on the project.
The process flow of the CoolCube sequential 3D integration is summarized in Figure 1.
Figure 2. Process flow scheme of 3D CoolCube TM integration: bottom level realization at high temperature (1050 °C), layer transfer (300 °C) and realization of the top level at low thermal budget (650 °C).
Figure 2. TEM cross-section of the 3D sequential structure up to M2 line.
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- P. Batude, “Three dimensional sequential integration: Study, fabrication and caracterisation,” Ph.D. dissertation (in French), Institut National Polytechnique de Grenoble - INPG, Grenoble, France, 2009.
- L. Brunet, P. Batude, C. Fenouillet-Beranger, P. Besombes, L. Hortemel, F. Ponthenier, B. Previtali, C. Tabone, A. Royer, C. Agraffeil, C. Euvrard-Colnat, A. Seignard, C. Morales, F. Fournel, L. Benaissa, T. Signamarcheix, P. Besson, M. Jourdan, R. Kachtouli, V. Benevent, J.-M. Hartmann, C. Comboroure, N. Allouti, N. Posseme, C. Vizioz, C. Arvet, S. Barnola, S. Kerdiles, L. Baud, L. Pasini, C.-M. V. Lu, F. Deprat, A. Toffoli, G. Romano, C. Guedj, V. Delaye, F. Boeuf, O. Faynot, and M. Vinet, “First demonstration of a CMOS over CMOS 3D VLSI CoolCube™ integration on 300mm wafers,” 2016, pp. 1–2. Available: http://dx.doi.org/10.1109/VLSIT.2016.7573428