Thermal atomic layer etching processes are disclosed. In some embodiments, the methods comprise at least one etch cycle in which the substrate is alternately and sequentially exposed to a first vapor phase halide reactant and a second vapor halide reactant. In some embodiments, the first reactant may comprise an organic halide compound. During the thermal ALE cycle, the substrate is not contacted with a plasma reactant.

Atomic layer etching (ALE) processes are disclosed. In some embodiments, the methods comprise at least one etch cycle in which the substrate is alternately and sequentially exposed to a first vapor phase non-metal halide reactant and a second vapor phase halide reactant. In some embodiments both the first and second reactants are chloride reactants. In some embodiments the first reactant is fluorinating gas and the second reactant is a chlorinating gas. In some embodiments a thermal ALE cycle is used in which the substrate is not contacted with a plasma reactant.

Atomic layer etching (ALE) processes are disclosed. In some embodiments, the methods comprise at least one etch cycle in which the substrate is alternately and sequentially exposed to a first vapor phase non-metal halide reactant and a second vapor phase halide reactant. In some embodiments both the first and second reactants are chloride reactants. In some embodiments the first reactant is fluorinating gas and the second reactant is a chlorinating gas. In some embodiments a thermal ALE cycle is used in which the substrate is not contacted with a plasma reactant.

The invention includes a method of promoting atomic layer etching (ALE) of a surface. In certain embodiments, the method comprises sequential reactions with a metal precursor and a halogen-containing gas. In other embodiments, the etching rate is increased by removing residual species bound to and/or adsorbed onto the surface.

A method for performing atomic layer etching (ALE) on a substrate, including the following method operations: performing a surface modification operation on a surface of the substrate, the surface modification operation configured to convert at least one monolayer of the substrate surface to a modified layer; performing a removal operation on the substrate surface, to remove the modified layer from the substrate surface, wherein removing the modified layer includes exposing the substrate surface to a metal complex, such that a ligand exchange reaction occurs between the metal complex and converted species of the modified layer; performing, following the removal operation, a plasma treatment on the substrate surface, the plasma treatment configured to remove residues formed from the exposure of the substrate surface to the metal complex, wherein the residues are volatilized by the plasma treatment; repeating the foregoing operations until a predefined thickness has been etched from the substrate surface.

A method for performing atomic layer etching (ALE) on a substrate, including the following method operations: performing a surface modification operation on a surface of the substrate, the surface modification operation configured to convert at least one monolayer of the substrate surface to a modified layer; performing a removal operation on the substrate surface, to remove the modified layer from the substrate surface, wherein removing the modified layer includes exposing the substrate surface to a metal complex, such that a ligand exchange reaction occurs between the metal complex and converted species of the modified layer; performing, following the removal operation, a plasma treatment on the substrate surface, the plasma treatment configured to remove residues formed from the exposure of the substrate surface to the metal complex, wherein the residues are volatilized by the plasma treatment; repeating the foregoing operations until a predefined thickness has been etched from the substrate surface.

An etchant is described that includes an N-heterocyclic carbene and optionally an appropriate solvent. The etchant was effective at etching a metallic surface having, for example, a metal oxide and/or metal, in both solution phase and vapour-phase. The etchant has been shown to effectively etch oxidized copper and tungsten.

The invention relates to a method for removing a metal deposit (2) arranged on a surface (5) in a chamber (1), said method including repeatedly performing a sequence including: a) a first phase of injecting chemical species suitable for oxidizing said metal deposit (2); and b) a second phase of injecting chemical species suitable for volatilizing the oxidized metal deposit, said second phase b) being performed after the first phase a).

The invention relates to a method for removing a metal deposit (2) arranged on a surface (5) in a chamber (1), said method including repeatedly performing a sequence including: a) a first phase of injecting chemical species suitable for oxidizing said metal deposit (2); and b) a second phase of injecting chemical species suitable for volatilizing the oxidized metal deposit, said second phase b) being performed after the first phase a).

Apparatuses for etching metal by depositing a material reactive with a metal to be etched and a halogen to form a volatile species and exposing the substrate to a halogen-containing gas and activation gas to etch the substrate are provided. Deposited materials may include silicon, germanium, titanium, carbon, tin, and combinations thereof. Apparatuses are suitable for fabricating MRAM structures and may be used to integrate ALD and ALE processes without breaking vacuum.