Backside reactive inhibition gas
Provided herein are methods and apparatuses for controlling uniformity of processing at an edge region of a semiconductor wafer. In some embodiments, the methods include providing a backside inhibition gas as part of a deposition-inhibition-deposition (DID) sequence.
1 . A method comprising:
providing a substrate having a metal deposited in features in the substrate, the substrate having a frontside, a backside, and an edge; and
performing a non-plasma inhibition treatment on surfaces of the deposited metal to inhibit nucleation on the treated surfaces, the non-plasma inhibition treatment comprising flowing an inhibition gas from a gas inlet on the frontside of the substrate and flowing the inhibition gas from the backside of the substrate around the edge of the substrate.
2 . The method of claim 1 , wherein the non-plasma inhibition treatment further comprises flowing a metal precursor from a gas inlet on the frontside of the substrate.
3 . The method of claim 2 , wherein no metal precursor is flowed from the backside of the substrate.
4 . The method of claim 1 , wherein flowing the inhibition gas from the gas inlet on the frontside of the substrate is performed concurrently or partially overlaps with flowing the inhibition gas from the backside of the substrate.
5 . The method of claim 1 , wherein flowing the inhibition gas from the gas inlet on the frontside of the substrate is alternated with flowing the inhibition gas from the backside of the substrate.
6 . The method of claim 5 , wherein the non-plasma inhibition treatment comprises an anneal period between flowing the inhibition gas from a gas inlet on the frontside of the substrate and flowing the inhibition gas from the backside of the substrate.
7 . The method of claim 1 , wherein the metal is one of tungsten (W), molybdenum (Mo), cobalt (Co), and ruthenium (Ru).
8 . The method of claim 1 , wherein the inhibition gas is a nitrogen-containing gas.
9 . The method of claim 8 , wherein the inhibition gas is ammonia (NH 3 ) or hydrazine (N 2 H 4 ).
10 . The method of claim 1 , further comprising, after the non-plasma inhibition treatment, exposing the features to a metal precursor and a reducing agent to deposit metal in the features, wherein deposition of the metal is delayed on the treated surfaces.
11 . The method of claim 10 , wherein the non-plasma inhibition treatment and the deposition are performed in different stations of a multi-station chamber.
12 . The method of claim 1 , wherein providing the substrate having a metal deposited in features in the substrate comprises depositing metal in the features.
13 . The method of claim 1 , wherein flowing the inhibition gas from the backside of the substrate around the edge of the substrate comprises flowing the inhibition gas from the backside of the substrate to a volume under an exclusion ring.