Patent ID: 6677242
Filing Date: 2004-01-13
Classification: G03F,H01J,H01L

Abstract:
A method for processing a silicon substrate disposed in a substrate process chamber of the type having a source power system and a bias power system, the method comprising:providing the substrate having a hard mask formed thereon inside the substrate process chamber, the substrate having a patterned photoresist overlying the hard mask, the patterned photoresist exposing portions of the hard mask; etching the exposed portions of the hard mask to expose portions of the silicon substrate underlying the hard mask; thereafter, exposing the patterned photoresist to a first plasma formed from a first process gas to remove the photoresist from the hard mask; thereafter, etching trenches on the exposed silicon substrate by exposing the substrate to a second plasma formed from a second process gas by applying RF energy from the source power system and biasing the plasma toward the substrate, each of the trenches having particular width, depth, and slope; exposing the silicon substrate to a third plasma formed from a third process gas including a halogen source in the substrate process chamber without applying bias power or applying bias power of no more than 0.06 Watt/cm2 to remove byproducts in the process chamber, wherein the width, depth, and slope of the trench are not significantly altered by the plasma ignited from the third process gas; and transferring the substrate out of the substrate processing chamber.