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US 10,950,498 B2Granted
Selective and self-limiting tungsten etch process
AssigneeApplied Materials, Inc.
InventorsSusmit Singha Roy, Srinivas Gandikota, Pramit Manna, Abhijit Basu Mallick
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Abstract
Methods of dep-etch in semiconductor devices (e.g. V-NAND) are described. A metal layer is deposited in a feature. The metal layer is removed by low temperature atomic layer etching by oxidizing the surface of the metal layer and etching the oxide in a layer-by-layer fashion. After removal of the metal layer, the features are filled with a metal.
Claims18
A processing method comprising:
- depositing a conformal liner in at least one feature on a substrate;
- wherein the conformal liner comprises one or more of titanium nitride (TiN) or tantalum nitride (TaN);
- depositing a metal layer on the conformal liner in the least one feature, the metal layer comprising a metal;
- oxidizing the metal to a first depth to form a metal oxide layer on the metal layer;
- and
- etching the metal oxide layer to selectively remove the metal oxide layer.
3 more elements
A processing method comprising:
- depositing a metal layer on a substrate surface, the substrate surface having at least one feature thereon, the at least one feature extending a feature depth from the substrate surface to a bottom surface, the at least one feature having a width defined by a first sidewall and a second sidewall, wherein the metal layer is deposited on the substrate surface, the first sidewall, the second sidewall, and the bottom surface of the at least one feature;
- and
- performing a process cycle comprising oxidizing the metal to a first depth for form a metal oxide layer on the metal layer, and etching the metal oxide layer to selectively remove the metal oxide layer.
A method of processing a substrate, the method comprising:
- forming a film stack on a substrate, the film stack comprising a plurality of alternating layers of an oxide material and a nitride material and the film stack have a stack thickness;
- forming an opening extending a depth from a top of the film stack surface to a bottom surface, the opening having a width defined by a first sidewall and a second sidewall;
- optionally forming a barrier layer on the film stack surface, and on the first sidewall, the second sidewall, and the bottom surface of the opening, the barrier layer comprising TiN with a thickness in the range of about 20 Å to about 50 Å;
- depositing a metal layer on the film stack so that the metal layer fills the opening and covers the top of the film stack with a metal layer thickness;
- and
- repeatedly oxidizing the surface of the metal layer to form a metal oxide layer and etching the metal oxide layer from the at least one feature until the metal layer is removed, oxidizing the surface comprising exposure to O2 and etching the metal layer oxide comprising exposure to a halide etchant.
3 more elements
Dependencies are inferred from the claim text.