System and method for depositing tungsten/titanium films

Claim 1

A method of forming a metal layer on a semiconductor wafer, the steps of the method comprising, in sequence: forming a tungsten/titanium layer on a semiconductor wafer by sputtering tungsten/titanium onto said semiconductor wafer in an evacuated chamber; exposing said tungsten/titanium layer to air; and then, forming an aluminum layer over said tungsten/titanium layer on said semiconductor wafer; whereby said step of exposing said tungsten/titanium layer causes at least partial oxidation of the titanium in said tungsten/titanium layer.

Claim 2

A method of forming a metal layer on a semiconductor wafer, the steps of the method comprising, in sequence: forming a tungsten/titanium layer on a semiconductor wafer by sputtering tungsten/titanium onto said semiconductor wafer in an evacuated chamber; exposing said tungsten/titanium layer to air; and then, forming an aluminum layer over said tungsten/titanium layer on said semiconductor wafer; whereby said step of exposing said tungsten/titanium layer causes at least partial oxidation of the titanium in said tungsten/titanium layer.

Claim 4

A method of forming a metal layer on a semiconductor wafer, the steps of the method comprising: forming a first portion of a tungsten/titanium layer on a semiconductor wafer by sputtering tungsten/titanium onto said semiconductor wafer in a first evacuated sputter station; forming a second portion of said tungsten/titanium layer by sputtering tungsten/titanium on top of said first portion of said tungsten/titanium layer in a second evacuated sputter station; and depositing an aluminum layer over said tungsten/titanium layer on said semiconductor wafer; whereby forming said tungsten/titanium layer in two steps in two sputter stations reduces the amount of tungsten/titanium deposited onto said sputter stations during the processing of each semiconductor wafer, thereby increasing the number of wafers which can be processed by said sputter stations before said tungsten/titanium deposited on said sputter stations needs to be removed.

Claim 5

A method of forming a metal layer on a semiconductor wafer, the steps of the method comprising: forming a first portion of a tungsten/titanium layer on a semiconductor wafer by sputtering tungsten/titanium onto said semiconductor wafer in a first evacuated sputter station; forming a second portion of said tungsten/titanium layer by sputtering tungsten/titanium on top of said first portion of said tungsten/titanium layer in a second evacuated sputter station; and depositing an aluminum layer over said tungsten/titanium layer on said semiconductor wafer; whereby forming said tungsten/titanium layer in two steps in two sputter stations reduces the amount of tungsten/titanium deposited onto said sputter stations during the processing of each semiconductor wafer, thereby increasing the number of wafers which can be processed by said sputter stations before said tungsten/titanium deposited on said sputter stations needs to be removed.

Claim 7

A method of forming metal layers on semiconductor wafers, the steps of the method comprising: sequentially processing semiconductor wafers by depositing on each semiconductor wafer on a metal layer, said step of depositing a metal layer on each semiconductor wafer including the steps of: forming a first portion of a tungsten/titanium layer on a semiconductor wafer by sputtering tungsten/titanium onto said semiconductor wafer in a first evacuated sputter station; forming a second portion of said tungsten/titanium layer by sputtering tungsten/titanium on top of said first portion of said tungsten/titanium layer in a second evacuated sputter station; and depositing an aluminum layer over said tungsten/titanium layer on said semiconductor wafer; said first and second forming steps also depositing tungsten/titanium onto said first and second sputter stations and thereby forming a tungsten/titanium layer inside said sputter stations which increases in thickness with the processing of each said semiconductor wafer; and removing said tungsten/titanium layer inside said sputter stations when the thickness of said layer exceeds a predefined threshold value; whereby forming said tungsten/titanium layer for each semiconductor wafer in two steps in two sputter stations reduces the amount of tungsten/titanium deposited onto said sputter stations during the processing of each semiconductor wafer, thereby increasing the number of wafers which can be processed by said sputter stations before said tungsten/titanium deposited on said sputter stations needs to be removed.

Claim 8

A method of forming metal layers on semiconductor wafers, the steps of the method comprising: sequentially processing semiconductor wafers by depositing on each semiconductor wafer on a metal layer, said step of depositing a metal layer on each semiconductor wafer including the steps of: forming a first portion of a tungsten/titanium layer on a semiconductor wafer by sputtering tungsten/titanium onto said semiconductor wafer in a first evacuated sputter station; forming a second portion of said tungsten/titanium layer by sputtering tungsten/titanium on top of said first portion of said tungsten/titanium layer in a second evacuated sputter station; and depositing an aluminum layer over said tungsten/titanium layer on said semiconductor wafer; said first and second forming steps also depositing tungsten/titanium onto said first and second sputter stations and thereby forming a tungsten/titanium layer inside said sputter stations which increases in thickness with the processing of each said semiconductor wafer; and removing said tungsten/titanium layer inside said sputter stations when the thickness of said layer exceeds a predefined threshold value; whereby forming said tungsten/titanium layer for each semiconductor wafer in two steps in two sputter stations reduces the amount of tungsten/titanium deposited onto said sputter stations during the processing of each semiconductor wafer, thereby increasing the number of wafers which can be processed by said sputter stations before said tungsten/titanium deposited on said sputter stations needs to be removed.

Claim 10

A system for forming a metal layer on a semiconductor wafer, comprising: a first evacuated sputter station which deposits a first portion of a first tungsten/titanium layer on a semiconductor wafer; a second evacuated sputter station which receives said semiconductor wafer from said first evacuated sputter station and which deposits a second portion of said first tungsten/titanium layer on top of said first portion of said tungsten/titanium layer; a third evacuated sputter station which receives said semiconductor wafer after processing of said semiconductor wafer in said second evacuated sputter station and which deposits an aluminum layer over said first tungsten/titanium layer on said semiconductor wafer; a fourth evacuated sputter station which receives said semiconductor wafer after processing of said semiconductor wafer in said third evacuated sputter station and which deposits a second tungsten/titanium layer over said aluminum layer; said first tungsten/titanium, aluminum and second tungsten/titanium layers together comprising a metal layer on said semiconductor wafer; said first and second sputter stations forming a tungsten/titanium layer inside said first and second sputter stations which increases in thickness with the processing of each said semiconductor wafer; and whereby said system forms said first tungsten/titanium layer for each semiconductor wafer in two steps in two sequential sputter stations, which reduces the amount of tungsten/titanium deposited inside each said sputter station during the processing of each semiconductor wafer, thereby increasing the number of wafers which can be processed by said sputter stations before said tungsten/titanium deposited inside said first and second sputter stations exceeds a prefefined threshold thickness, at which time said system needs to be shut down so as to remove tungsten/titanium deposited inside said first and second sputter stations.

Claim 11

A system for forming a metal layer on a semiconductor wafer, comprising: a first evacuated sputter station which deposits a first portion of a first tungsten/titanium layer on a semiconductor wafer; a second evacuated sputter station which receives said semiconductor wafer from said first evacuated sputter station and which deposits a second portion of said first tungsten/titanium layer on top of said first portion of said tungsten/titanium layer; a third evacuated sputter station which receives said semiconductor wafer after processing of said semiconductor wafer in said second evacuated sputter station and which deposits an aluminum layer over said first tungsten/titanium layer on said semiconductor wafer; a fourth evacuated sputter station which receives said semiconductor wafer after processing of said semiconductor wafer in said third evacuated sputter station and which deposits a second tungsten/titanium layer over said aluminum layer; said first tungsten/titanium, aluminum and second tungsten/titanium layers together comprising a metal layer on said semiconductor wafer; said first and second sputter stations forming a tungsten/titanium layer inside said first and second sputter stations which increases in thickness with the processing of each said semiconductor wafer; and whereby said system forms said first tungsten/titanium layer for each semiconductor wafer in two steps in two sequential sputter stations, which reduces the amount of tungsten/titanium deposited inside each said sputter station during the processing of each semiconductor wafer, thereby increasing the number of wafers which can be processed by said sputter stations before said tungsten/titanium deposited inside said first and second sputter stations exceeds a prefefined threshold thickness, at which time said system needs to be shut down so as to remove tungsten/titanium deposited inside said first and second sputter stations.