Gettering technique for silicon-on-insulator wafers

摘要

A gettering layer in a silicon-on-insulator wafer. The gettering layer may be formed by implanting gas-forming particles or precipitate-forming particles beneath the active region of the silicon layer and thermally treating the gas-forming ions to produce microbubbles or precipitates within the silicon layer. The microbubbles an/or precipitates create trapping sites for mobile impurity species, thus gettering the impurities. In another embodiment, a polysilicon layer is formed on a donor silicon wafer prior to separating a thin layer of silicon from the donor wafer. The thin layer of silicon is bonded to a backing wafer, the polysilicon layer provides a gettering layer between the active silicon and the backing wafer.