Patent ID: 7268086

Claim:
A method for reducing a critical dimension, the method comprising: forming a dielectric layer on a substrate; forming a patterned photoresist layer on the dielectric layer to expose a portion of the dielectric layer, wherein the patterned photoresist layer comprises a first line width; and performing an etching process to remove the exposed dielectric layer and to form the dielectric layer with a final line width which is smaller than the first line width, using the patterned photoresist layer as an etching mask, wherein the etching process is performed under conditions that include: a source power, which is applied on an etching chamber for performing the etching process, lower than 200 W when a bottom power applied on the etching chamber is greater than 250 W; a pressure between 80 to 400 torrs; and a gas comprising a fluorocarbon compound and an oxygen gas, wherein a ratio of a flow rate of the fluorocarbon compound to a flow rate of the oxygen gas is greater than 0 and less than 10.