METHOD FOR REALIZING ISOLATION AMONG ACTIVE REGIONS OF GERMANIUM-BASED MOS DEVICE

摘要

Discloses is a method for realizing isolation among active regions of a germanium-based MOS device. A surface of a germanium-based substrate is covered by a thin layer of polycrystalline silicon or polycrystalline silicon germanium; then, with the active regions being protected, a germanium-dioxide isolating structure, having a surface covered by a silicon dioxide layer or a silicon germanium oxide layer, is formed by two-step oxidation. The two-step oxidation process using polycrystalline silicon or polycrystalline silicon germanium as a sacrifice layer is conducive to improving the isolating quality of the germanium dioxide and reducing the bird's beak effect generated by oxidation of local field oxygen, so that the performance of the germanium device is significantly improved.