Discretionary gettering of semiconductor circuits

摘要

A semiconductor wafer (32) is patterned to have gettering areas (36-38) selectively positioned proximate devices (44-46) which require gettering. The areas (36-38) comprise germanium-doped silicon having a germanium concentration of approximately 1.5%-2.0%. The germanium creates a lattice mismatch between the substrate (32) and an epitaxial layer (34) which is sufficient to produce defects capable of gettering contaminants. The gettering areas (36-38) may be formed by selective deposition, selective etching, ion-implantation or selective diffusion techniques.