October 15, 2007 — Okmetic, supplier of silicon wafers for MEMS sensors, has created a new silicon-on-insulator (SOI) product with built-in gettering properties. Since the gettering of metal impurities is built in the starting material, Okmetic G-SOI promises IC-integrated MEMS processes with significant benefits including smaller device size, improved yields, streamlined process, and decreased cost.

The gettering effect is achieved by adding a thin polysilicon layer between the active layer and buried oxide of a BSOI structure. The solution is layout independent, eliminates the need for mask layers and enables skipping the implant process step.

“Standard BSOI structures may suffer from poor gettering efficiency because standard backside or internal gettering methods are not efficient enough in SOI wafers, or the active layer has no gettering sites and the thin SOI layer has had to accommodate all impurities coming from the surface,” says Jari Mäkinen, Okmetic’s Product Development Manager. “The benefits of Okmetic G-SOI have been demonstrated by improved gate oxide integrity and breakdown voltage, and G-SOI is therefore the optimal solution for CMOS and MEMS integrated designs.”