Method for forming deep trench capacitor with liquid phase deposition oxide as collar oxide

摘要

A method for forming a deep trench capacitor mainly utilizes a liquid phase deposition (LPD) oxide to form a collar oxide layer in the trench, followed by forming a conductive layer serving as an upper electrode of the deep trench capacitor, thereby avoiding collar oxide residue in the conductive layer and thus forming good electrical connection. And, the method of the present invention does not need a dry etch to remove the unnecessary collar oxide layer such that the process can be simplified.