2 - Technologies

High aspect ratio SOI (Silicon On Insulator) process is similar to the SIMPLE technology. SiO₂ mask defines the pattern of micromechanical structures, and the same material is used as sacrificial layer. Deep dry etching creates the structures, then a selective etching process removes both the sacrificial and mask SiO₂ layers to release them.

Thick SOI (Silicon On Insulator) technology combines the sacrificial layer, epitaxy, and implanting processes together. The structural layer is an epitaxy, deposited over the patterned sacrificial layer. The epitaxy is then processed with p-implantation, coated with BPSG (Boron Phosphor Silica Glass) passivation and contacted with metal pads, like a normal silicon wafer. In the next phase, the implanted epitaxy is etched in the needed pattern and then the microstructure is released by etching the sacrificial layer away.