Application of Elevated-Laser-Liquid-Phase-Epitaxy (ELLPE) Technique on Different Oriented Wafers for Monolithic 3DIC Integration

This study presents an innovative Elevated-Laser-Liquid-Phase-Epitaxy (ELLPE) technique for producing single-crystal channels in upper-layer circuits. By employing a green nanosecond laser process, the overall process temperature remains within the low thermal budget of monolithic 3DIC, enabling the transformation of amorphous silicon thin films into high-quality continuous films with uniform crystal orientation. Furthermore, we confirmed the successful fabrication of high-quality single-crystal continuous films, aligning with the crystallographic orientation of wafers across various lattice directions through EBSD analysis, and their single-crystalline nature were verified through TEM analysis. These research findings effectively overcome the historical limitation of sequential integration, which was restricted to generating polycrystalline channels exclusively in upper-layer circuits, thus opening avenues for numerous future applications.