Method of forming a semiconductor isolation trench

A method for forming a semiconductor isolation trench comprising:

• forming a pad oxide layer over a substrate;
• forming a barrier layer over the pad oxide layer;
• forming a masking layer over the barrier layer;
• patterning the masking layer to form at least one opening in the masking layer;
• etching at least a part of the barrier layer and at least a part of the pad oxide layer through the at least one opening and stopping the etching at a top surface of the substrate corresponding to at least one isolation trench;
• growing an oxide layer on at least the top surface of the substrate corresponding to the at least one isolation trench;
• and
• etching the oxide layer and at least a portion of the substrate to form at least one isolation trench opening.

A method for forming a semiconductor isolation trench comprising:

• providing a substrate with a pad oxide layer over the substrate and a barrier layer over the pad oxide layer;
• forming a masking layer over the barrier layer;
• patterning the masking layer to form at least one opening in the masking layer;
• etching at least a part of the barrier layer and at least a part of the pad oxide layer through the at least one opening resulting in a trench pad oxide layer;
• stopping an etching of the trench pad oxide layer substantially at a top surface of the substrate corresponding to at least one isolation trench;
• growing an oxide layer on at least the top surface of the substrate corresponding to the at least one isolation trench;
• and
• etching the oxide layer and at least a portion of the substrate to form at least one isolation trench opening.