New Heterostructures and 3D Devices Obtained at CEA/LETI by the Bonding and Thinning Method

Abstract

Direct wafer bonding and thinning technologies are now extensively used in combination to produce SOI wafers. Emerging demands of new functionalities at the material or device level for 3D integration have allowed to increase the level of maturity of these technologies. This paper deals with the innovative 3D substrates and devices we have obtained in the frame of fruitful collaborations.

Low Temperature Direct Bonding 3D Stacking Technologies for High Density Device Integration

“…Metal bonding: The bonding with Cu, W, Ti of plain metal layers has been demonstrated [4], fig 1.. Smart cut and SPER: a way to thin the upper substrate down to tens of nm is to use the Smart Cut TM process which combines hydrogen implantation and bonding. Mainly used for SOI production is was recently demonstrated with metal bonding at low temperature [6]. In that case, to recover the upper silicon quality a solid phase epitaxial recristallization technique (SPER) was used.…”