Process for the production of a semiconductor device in which a silicon wafer is provided with LOCAL field oxide areas.

摘要

A method of manufacturing a semiconductor device, in which on a surface (1) of a silicon wafer (2) an oxidation mask (3) is locally provided, whereupon the wafer is subjected to an oxidation treatment, in which a layer of field oxide (8) is formed. In order to compensate for thickness losses during further processing steps, a layer of field oxide (8) has to be formed having a thickness exceeding a desired isolation thickness. This initial thickness is realized according to the invention in such a manner that a layer is formed having a thickness which is larger than said initial thickness, whereupon in a plasma with reactive ions this layer is etched back to the desired initial thickness. In the layer thus formed, having the desired initial thickness, the layer of field oxide is prevented from locally being etched in an etching solution (such as the hydrofluoride solution) at a higher rate during further processing steps.