Patent ID: 6420099
Filing Date: 2002-07-16
Classification: H01L

Abstract:
A method, comprising:providing a metal stack comprising a first refractory metal layer, a layer comprising aluminum over the first refractory metal layer, and a second refractory metal layer over the aluminum layer; providing a tungsten-containing layer in contact with the second refractory metal layer, such second refractory metal layer being of a material different from the tungsten-containing layer; providing a mask over a selected region of the tungsten-containing layer, such mask exposing an unmasked portion of the tungsten-containing layer; exposing the mask to an etch, such etch removing the unmasked portion of the tungsten-containing layer and the second refractory metal layer, thereby forming the tungsten-containing layer into a hard mask for the underlying metal stack layer, such hard mask exposing an underlying portion of the aluminum layer; and bringing a dry etch into contact with the hard mask to selectively remove exposed portions of the underlying aluminum layer and first refractory metal layer while leaving the hard mask substantially unetched.