generally consist of a wafer of p type monocrystalline silicon the substrate 206 shown in the figures comprises a small portion of such a wafer the steps for initially preparing the wafer and for forming field oxide are well known to those skilled in the art and are not therefore described here the steps for fabricating the semiconductor structure 202 shown in fig2 a from a prepared wafer are in sequence 1 form the thin gate oxide 212 of approximately 50 to 400 angstroms 3 pattern and etch the polysilicon gate layer using conventional photoresist masking and etching in order to form the polysilicon gate member 210 fig2 a and 4 reoxidize the gate member 210 to create a reoxidized polysilicon layer 226 these processing steps are well known to those skilled in the art and are therefore not further described here referring to the cross sectional representation of fig2 b the next step in a conventional oxide spacer etch is to deposit a layer 234 of tetro ethyl orthosilicate teos having a thickness of approximately 3000 angstroms the multi layer structure of fig2 b is then inserted into the chamber of a plasma etching apparatus such as that shown in fig1 the ensuing high power plasma etching process operates to destroy sequential horizontal planes of the teos.