Method of forming an interlayer dielectric

A method for forming a semiconductor device comprising:

• providing a semiconductor substrate;
• forming a first plurality of transistors on a first portion of the semiconductor substrate;
• forming a second plurality of transistors on a second portion of the semiconductor substrate;
• forming a first stressor layer of silicon-lean silicon nitride over the first and second pluralities of transistors having compressive stress;
• selectively removing the first stressor layer from over the first plurality of transistors to leave a remaining portion of the first stressor layer;
• forming a second stressor layer of silicon-lean silicon nitride over remaining portion of the first stressor layer and the first and second pluralities of transistors, wherein the second stressor layer has tensile stress;
• forming a photoresist layer over the second stressor layer;
• patterning the photoresist layer to leave a portion of the photoresist layer that overlaps the remaining portion of the first stressor layer and exposes a first portion of the second stressor layer;
• and applying a wet chemistry comprising hydrofluoric acid to the portion of the of the photoresist layer and the first portion of the second stressor layer, wherein wet chemistry comprising hydrofluoric acid is characterized by etching the second stressor layer at a greater rate than the first stressor layer.

A method for forming a semiconductor device comprising:

• providing a semiconductor substrate;
• forming a plurality of N-channel transistors on a first portion of the semiconductor substrate;
• forming a plurality of P-channel transistors on a second portion of the semiconductor substrate, wherein the second portion is adjacent to the first portion;
• forming a compressive stressor layer of silicon-lean silicon nitride over the plurality of N-channel transistors and over the plurality of P-channel transistors;
• selectively removing the compressive stressor layer from over the plurality N-channel of transistors to leave a remaining portion of the compressive stressor layer;
• forming a tensile stressor layer of silicon-lean silicon nitride over the remaining portion of the compressive stressor layer and the plurality of P-channel transistors;
• and
• forming a photoresist layer over the compressive stressor layer;
• patterning the photoresist layer to leave a portion of the photoresist layer that overlaps the remaining portion of the compressive stressor layer and exposes a first portion of the tensile stressor layer;
• and
• applying a wet chemistry comprising hydrofluoric acid to the portion of the of the photoresist layer and the first portion of the second stressor layer, wherein wet chemistry comprising hydrofluoric acid is characterized by etching the second stressor layer at a greater rate than the first stressor layer.