Bonding and thinning technologies pave the way to new substrates for MEMS and power ICs, and enable the transfer of finished circuits to new supports.
Layer transfer and direct bonding technologies that leverage molecular adhesion and mechanical and chemical thinning open doors to new generations in advanced and engineered substrates. A spin-off of CEA-Léti, TraciT Technologies has developed these technologies, which are complementary to the Smart Cut™ process. They enable embedding functions at the substrate level, and the creation of entirely new structures through the transfer of fullyprocessed wafers onto different supports.
New substrates such as Patterned SOI, Debondable SOI and Si-Si structures can be achieved.
Patterned SOI enables local vertical contact between the top layer and the handle substrate, which can locally improve the electrical or thermal properties of the structure. Debondable BSOI (D-BSOI™) provides a processed thin membrane of few tens of microns, which can be stand-alone or be transferred onto another support. Target applications for these new substrates include the power IC industry, especially for power management in automotives, home automation, and mobile computing. In the MEMS industry, they are well suited for pressure sensors and accelerometers for automotive and industrial applications.
Processed layer transfer offers new solutions to wafer level packaging issues and enables stacking of different functions for 3D applications. Finished integrated circuits can be moved onto various supports such as silicon, fused silica or pre-processed wafers, by simple or double transfer. The ability to transfer finished circuits onto new supports is a promising way to improve device performance or to enable hetero-structure stacking for 3D-integration. For example, RF performance of chips for mobile phones or computers can be improved by transferring the circuits onto a fully insulated support.