Oxide removal method for improvement of subsequently grown oxides

A method for removing oxide from the surface of a semiconductor body having a thick oxide and an adjoining nitride-covered thin oxide prior to forming a gate oxide for a field effect device, comprising the steps of:

• etching the thick oxide so that a portion of the thick oxide remains, and has a thickness comparable to that of the thin oxide;
• subsequent to the thick oxide etching step, removing the nitride covering the thin oxide;
• and
• subsequent to the nitride removing step, etching the thin oxide and the remaining portion of the thick oxide without appreciably over-etching the surface of the semiconductor body.

A method for avoiding degredation of a surface of a semiconductor body having a thick oxide layer and an adjoining nitride-masked first thin oxide layer, comprising the steps of:

• converting the thick oxide into a second thin oxide;
• removing the nitride layer subsequent to the thick oxide converting step;
• and
• etching the first and second thin oxides subsequent to the nitride removing step, wherein the thickness of the first and second thin oxides and the duration of etching are such that appreciable degredation of the surface of the semiconductor body does not occur.

A method for avoiding degredation of a surface of a semiconductor body having a thick oxide layer and an adjoining nitride-masked first thin oxide layer, comprising the steps of:

• converting the thick oxide into a second thin oxide;
• removing the nitride layer subsequent to the thick oxide converting step;
• and
• etching the first and second thin oxides subsequent to the nitride removing step, wherein the thickness of the first and second thin oxides and the duration of etching are such that the surface of the semiconductor body remains free of appreciable surface micro-roughness.