Method of forming a barrier layer between a silicon substrate and an aluminum electrode of a semiconductor device

Claim 1

A method of forming an electrode layer, comprising aluminum, on a substrate, comprising silicon, comprising: forming an insulating layer on said substrate, which insulating layer has at least one contact hole therein exposing said silicon and adapted to receive said electrode on said silicon therethrough thereby producing a first substrate; exposing said first substrate to reactive sputtering with a refractory metal target in an environment comprising, a mixed gas comprising an inert gas, a reactive gas comprising a gas selected from nitrogen, a nitrogen compound, a carbon compound and a boron compound, and oxygen at a temperature of about 350° to 600° C., thereby producing a second substrate containing a high density barrier layer refractory metal compound thereon comprising a reaction product of said reactive gas and said refractory metal, wherein the quantity of oxygen in said mixed gas is sufficient to create refractory metal oxide at the grain boundaries in said barrier layer in an amount sufficient to decrease the failure rate thereof but insufficient to significantly increase the resistivity thereof; and forming a layer, comprising aluminum, on said barrier layer at least in said hole.

Claim 2

A method of forming an electrode layer, comprising aluminum, on a substrate, comprising silicon, comprising: forming an insulating layer on said substrate, which insulating layer has at least one contact hole therein exposing said silicon and adapted to receive said electrode on said silicon therethrough thereby producing a first substrate; exposing said first substrate to reactive sputtering with a refractory metal target in an environment comprising, a mixed gas comprising an inert gas, a reactive gas comprising a gas selected from nitrogen, a nitrogen compound, a carbon compound and a boron compound, and oxygen at a temperature of about 350° to 600° C., thereby producing a second substrate containing a high density barrier layer refractory metal compound thereon comprising a reaction product of said reactive gas and said refractory metal, wherein the quantity of oxygen in said mixed gas is sufficient to create refractory metal oxide at the grain boundaries in said barrier layer in an amount sufficient to decrease the failure rate thereof but insufficient to significantly increase the resistivity thereof; and forming a layer, comprising aluminum, on said barrier layer at least in said hole.

Claim 8

A method of forming an aluminum or aluminum alloy electrode layer on a silicon substrate; said method comprising the steps of: forming an insulating layer, having a contact hole for contacting the electrode layer with the silicon substrate, on the silicon substrate thereby producing a first silicon substrate; forming a contact layer, comprising titanium, on said first silicon substrate having a thickness less than 20 nm thereby producing a second silicon substrate; placing said second silicon substrate in a reactive sputtering means; placing a target composed of titanium metal in said reactive sputtering means; supplying a mixed gas consisting of argon, a gas comprising nitrogen and oxygen to said reactive sputtering means; controlling the temperature of said second silicon substrate to between about 350° C. and 600° C.; performing reactive sputtering by said reactive sputtering means thereby forming a high density barrier layer, consisting of titanium nitride produced during said reactive sputtering, on said second silicon substrate, said mixed gas comprising sufficient oxygen to cause sufficient titanium oxide to be produced at the grain boundaries in said barrier layers to reduce the failure rate thereof but insufficient to substantially increase the resistivity thereof, said barrier layer effectively preventing silicon atoms in the silicon substrate from diffusing into the aluminum electrode and aluminum atoms in the aluminum electrode from diffusing into the silicon substrate, and said contact layer causing said barrier layer to effectively contact said silicon substrate; and forming an aluminum or aluminum alloy layer on said barrier layer.

Claim 9

A method of forming an aluminum or aluminum alloy electrode layer on a silicon substrate; said method comprising the steps of: forming an insulating layer, having a contact hole for contacting the electrode layer with the silicon substrate, on the silicon substrate thereby producing a first silicon substrate; forming a contact layer, comprising titanium, on said first silicon substrate having a thickness less than 20 nm thereby producing a second silicon substrate; placing said second silicon substrate in a reactive sputtering means; placing a target composed of titanium metal in said reactive sputtering means; supplying a mixed gas consisting of argon, a gas comprising nitrogen and oxygen to said reactive sputtering means; controlling the temperature of said second silicon substrate to between about 350° C. and 600° C.; performing reactive sputtering by said reactive sputtering means thereby forming a high density barrier layer, consisting of titanium nitride produced during said reactive sputtering, on said second silicon substrate, said mixed gas comprising sufficient oxygen to cause sufficient titanium oxide to be produced at the grain boundaries in said barrier layers to reduce the failure rate thereof but insufficient to substantially increase the resistivity thereof, said barrier layer effectively preventing silicon atoms in the silicon substrate from diffusing into the aluminum electrode and aluminum atoms in the aluminum electrode from diffusing into the silicon substrate, and said contact layer causing said barrier layer to effectively contact said silicon substrate; and forming an aluminum or aluminum alloy layer on said barrier layer.

Claim 10

A method as claimed in 7, wherein said oxygen gas used in said step of supplying a mixed gas, is about 1-5% in volume of said mixed gas.

Claim 11

A method as claimed in 7, wherein said insulating layer is selected from the group consisting of silicon dioxide, a phosphosilicate glass, silicon nitride and a borophosphosilicate glass.