Chlorine-free removal of molybdenum oxides from substrates
Methods of removing molybdenum oxide from a surface of a substrate comprise exposing the substrate having a molybdenum oxide layer on the substrate to a halide etchant having the formula R m SiX 4-m , wherein m is an integer from 1 to 3, X is selected from iodine (I) and bromine (Br) and R is selected from the group consisting of a methyl group, ethyl group, propyl group, butyl group, cyclohexyl group and cyclopentyl group. The methods may be performed in a back-end-of-the line (BEOL) process, and the substrate contains a low-k dielectric material.
1 . A method of removing molybdenum oxide from a surface of a substrate, the method comprising:
exposing the substrate having a molybdenum oxide layer on the substrate to a halide etchant having the formula R m SiX 4-m , wherein m is an integer from 1 to 3, X is selected from iodine (I) and bromine (Br) and R is selected from the group consisting of a methyl group, ethyl group, propyl group, butyl group, cyclohexyl group and cyclopentyl group.
2 . The method of claim 1 , wherein the halide is bromine (Br).
3 . The method of claim 2 , wherein exposing the substrate occurs at temperature in a range of from a range of from 150° C. to 400° C.
4 . The method of claim 3 , wherein the temperature is in a range of from 200° C. to 400° C.
5 . The method of claim 3 , wherein the temperature is in a range of from 250° C. to 400° C.
6 . The method of claim 1 , wherein the halide is iodine (I).
7 . The method of claim 6 , wherein exposing the substrate occurs at temperature in a range of from a range of from 150° C. to 400° C.
8 . The method of claim 7 , wherein the temperature is in a range of from 200° C. to 400° C.
9 . The method of claim 8 , wherein the temperature is in a range of from 250° C. to 400° C.
10 . The method of claim 1 , wherein exposing the substrate occurs at temperature in a range of from a range of from 150° C. to 400° C.
11 . The method of claim 10 , wherein the temperature is in a range of from 200° C. to 400° C.
12 . The method of claim 10 , wherein the temperature is in a range of from 250° C. to 400° C.
13 . The method of claim 1 , further comprising exposing the substrate having the molybdenum oxide layer on the substrate to a purge gas, and wherein exposing the substrate having the molybdenum oxide layer on the substrate to the halide etchant and the purge gas comprises an atomic layer etching cycle.
14 . The method of claim 13 , wherein the purge gas is an inert gas.
15 . The method of claim 13 , wherein exposing the substrate and the molybdenum oxide layer reduces the thickness of the molybdenum oxide layer.
16 . The method of claim 15 , further comprising repeating the cycle multiple times.
17 . The method of claim 16 , further comprising removing the molybdenum oxide layer from the substrate.
18 . The method of claim 13 , wherein the method is performed in a back-end-of-the line (BEOL) process.
19 . The method of claim 18 , wherein the substrate contains a low-k dielectric material.
20 . A non-transitory, computer readable medium having instructions stored thereon that, when executed, causes the method of claim 13 to be performed.