Method of high density plasma metal etching

Claim 1

A method of manufacturing a semiconductor device having a dense array of conductive lines, which method comprises: forming an insulating layer; forming a layer of conductive material on the insulating layer; forming a mask on the layer of conductive material, which mask contains a pattern defining a dense array of conductive lines bordered by an open field; and etching the conductive layer through the mask with a high density plasma generated by a gas flow containing nitrogen in an amount ranging from about 20 to about 50% volume of the total gas flow and sufficient to increase the etch rate of the conductive material within the dense array to no less than the etch rate of the conductive material in the open field, wherein the conductive material is an aluminum alloy containing more than about 0.5% by weight of copper, and further comprising depositing the aluminum alloy at a temperature less than about 150° C. or at a temperature greater than about 350° C.

Claim 2

A method of manufacturing a semiconductor device having a dense array of conductive lines, which method comprises: forming an insulating layer; forming a layer of conductive material on the insulating layer; forming a mask on the layer of conductive material, which mask contains a pattern defining a dense array of conductive lines bordered by an open field; and etching the conductive layer through the mask with a high density plasma generated by a gas flow containing nitrogen in an amount ranging from about 20 to about 50% volume of the total gas flow and sufficient to increase the etch rate of the conductive material within the dense array to no less than the etch rate of the conductive material in the open field, wherein the conductive material is an aluminum alloy containing more than about 0.5% by weight of copper, and further comprising depositing the aluminum alloy at a temperature less than about 150° C. or at a temperature greater than about 350° C.