Tantalum-containing material removal
First Claim
1. A method of etching tantalum-containing material from a substrate, the method comprising:
- placing the substrate into a substrate processing region, wherein the substrate comprises exposed tantalum-containing material, exposed titanium nitride, and exposed hafnium oxide;
etching the tantalum-containing material and the titanium nitride by flowing diatomic chlorine into the substrate processing region while forming a local plasma from the diatomic chlorine and forming chlorine plasma effluents, wherein etching the tantalum-containing material and the titanium nitride further comprises accelerating the chlorine plasma effluents towards the substrate by biasing the local plasma relative to the substrate, wherein etching the tantalum-containing material and the titanium-nitride leaves a residue on a remaining portion of the substrate, and wherein the hafnium oxide is substantially maintained during the etching;
removing the residue from the remaining portion of the substrate by flowing a hydrogen-containing precursor into the (same) substrate processing region while forming a hydrogen local plasma from the hydrogen-containing precursor to form hydrogen-containing plasma effluents, wherein flowing of the hydrogen-containing precursor occurs after flowing the diatomic chlorine; and
removing the substrate from the substrate processing region.
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Abstract
Methods are described herein for etching tantalum-containing films with various potential additives while still retaining other desirable patterned substrate portions. The methods include exposing a tantalum-containing film to a chlorine-containing precursor (e.g. Cl2) with a concurrent plasma. The plasma-excited chlorine-containing precursor selectively etches the tantalum-containing film and other industrially-desirable additives. Chlorine is then removed from the substrate processing region. A hydrogen-containing precursor (e.g. H2) is delivered to the substrate processing region (also with plasma excitation) to produce a relatively even and residue-free tantalum-containing surface. The methods presented remove tantalum while retaining materials elsewhere on the patterned substrate.
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Citations
18 Claims
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1. A method of etching tantalum-containing material from a substrate, the method comprising:
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placing the substrate into a substrate processing region, wherein the substrate comprises exposed tantalum-containing material, exposed titanium nitride, and exposed hafnium oxide; etching the tantalum-containing material and the titanium nitride by flowing diatomic chlorine into the substrate processing region while forming a local plasma from the diatomic chlorine and forming chlorine plasma effluents, wherein etching the tantalum-containing material and the titanium nitride further comprises accelerating the chlorine plasma effluents towards the substrate by biasing the local plasma relative to the substrate, wherein etching the tantalum-containing material and the titanium-nitride leaves a residue on a remaining portion of the substrate, and wherein the hafnium oxide is substantially maintained during the etching; removing the residue from the remaining portion of the substrate by flowing a hydrogen-containing precursor into the (same) substrate processing region while forming a hydrogen local plasma from the hydrogen-containing precursor to form hydrogen-containing plasma effluents, wherein flowing of the hydrogen-containing precursor occurs after flowing the diatomic chlorine; and removing the substrate from the substrate processing region. - View Dependent Claims (2, 3, 4)
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5. A method of etching tantalum-containing material from a substrate, the method comprising:
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placing the substrate into a first substrate processing region, wherein the substrate comprises tantalum-containing material and an overlying tantalum oxide; reducing the overlying tantalum oxide and exposing the tantalum-containing material and a titanium nitride by flowing a hydrogen-containing precursor into a first substrate processing region housing the substrate while forming a hydrogen plasma in the first substrate processing region; placing the substrate into a second substrate processing region; etching the tantalum-containing material and the titanium nitride by flowing a chlorine-containing precursor into the second substrate processing region while forming a local plasma from the chlorine-containing precursor to form chlorine-containing plasma effluents, wherein forming the local plasma further comprises accelerating the chlorine-containing plasma effluents towards the substrate by biasing the local plasma relative to the substrate, wherein the second substrate processing region is maintained between about 3 Torr and about 20 Torr during the etching; flowing a hydrogen-containing precursor into the second substrate processing region while forming a second hydrogen plasma in the second substrate processing region, wherein flowing of the hydrogen-containing precursor occurs after flowing the chlorine-containing precursor; and removing the substrate from the second substrate processing region. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14)
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15. A method of etching tantalum-containing material and tantalum oxide, the method comprising:
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transferring a substrate into a substrate processing region, wherein the substrate comprises tantalum-containing material and a thin tantalum oxide layer thereon; removing the thin tantalum oxide layer by flowing a hydrogen-containing precursor into the substrate processing region while forming a local plasma from the hydrogen-containing precursor; etching the tantalum-containing material and an exposed titanium nitride by flowing a chlorine-containing precursor into the substrate processing region while forming a chlorine plasma from the chlorine-containing precursor to form chlorine-containing plasma effluents, wherein etching the tantalum-containing material occurs after removing the thin tantalum oxide layer, wherein removing the tantalum-containing material leaves a residue on a post-etch surface of the tantalum-containing material, wherein the substrate processing region is maintained at a pressure between about 3 Torr and about 20 Torr during the etching, wherein the substrate further comprises an exposed hafnium oxide, and wherein the exposed hafnium oxide is substantially maintained during the etching; removing the chlorine-containing precursor by purging the substrate processing region with an inert gas; removing the residue from the post-etch surface by flowing a second hydrogen-containing precursor into the substrate processing region while forming a second local plasma from the second hydrogen-containing precursor; and transferring the substrate out of the substrate processing region. - View Dependent Claims (16, 17, 18)
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Specification