Low-k dielectric etch

摘要

A method for etching a dielectric layer below a photoresist mask is provided. A wafer with the dielectric layer disposed below a photoresist mask is provided in an etch chamber. An etch gas comprising CF₄ and H₂ is provided into the etch chamber wherein the CF₄ has a flow rate and the H₂ has a flow rate, wherein the flow rate of H₂ is greater than the flow rate of CF₄. A plasma is formed from the etch gas. Features are etched into the dielectric layer through the etch mask using the plasma formed from the etch gas.