METHOD FOR PLANARIZING SEMICONDUCTOR STRUCTURE

摘要

The invention provides a method for planarizing over a recessed area of a semiconductor structure. The method involves the creation of a series of subminimum (i.e. 50 to 500 Angstroms thick) silicon pillars (22) extending vertically upward from the base of a trench (20) formed in a substrate (10), and oxidizing the pillars to form oxide pillars (24). When the substrate is covered with a conformal CVD oxide layer (25), the pillars prevent the formation of a single deep depression above the trench. The structure is chem-mech polished to leave a planarized substrate with recessed isolation regions (26).