Semiconductor wafer, for semiconductor device production, has a non-uniform lattice defect distribution or oxygen precipitate nucleation center concentration profile

摘要

A semiconductor wafer, having a non-uniform lattice defect distribution or oxygen precipitate nucleation center concentration profile, is new. A semiconductor wafer, comprising a central region between two inner layers located between an upper layer and a lower layer and having a non-uniform lattice defect distribution, has a defect concentration maximum in both the central region and the lower layer or in the inner layer immediately below the upper layer. Independent claims are also included for the following: (i) a process for producing the above wafer; (ii) similar semiconductor wafers having an oxygen precipitate nucleation center concentration maximum in both the central region and the lower layer or in the inner layer immediately below the upper layer, the concentration being so low at the front face and in the upper layer that a 1-100 mu thick precipitate-free layer is formed at the front face during subsequent thermal treatment without outwards oxygen diffusion; and (iii) a process for producing the above wafers (ii).