Patent ID: 6344415
Filing Date: 2002-02-05
Classification: H01L

Abstract:
A method for forming shallow trench isolation structure, comprising the steps of:providing a substrate; forming a pad oxide layer over the substrate; forming an amorphous silicon layer over the pad oxide layer; forming a mask layer over the amorphous silicon layer; patterning the mask layer, the amorphous silicon layer, the pad oxide layer and the substrate to form a trench and an active region; performing an oxidation to form a liner oxide layer on exposed sidewalls of the amorphous silicon layer and an exposed substrate surface inside the trench, wherein the mask layer serves as a protection layer on a top surface of the amorphous silicon layer; depositing insulation material into the trench and over the substrate to form an insulation layer; performing chemical-mechanical polishing to remove a portion of the insulation layer and a portion of the mask layer and retaining an insulation plug inside the trench such that a top surface of the insulation plug and a top surface of the mask layer are at the same level; patterning the mask layer to expose a portion of the amorphous silicon layer between two neighboring insulation plugs; performing an ion implantation; removing the mask layer; and removing the amorphous layer.