US 12,444,610 B2
Methods for etching a substrate using a hybrid wet atomic layer etching process
Paul Abel, Austin, TX (US); and Jacques Faguet, Austin, TX (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Jan. 21, 2022, as Appl. No. 17/580,879.
Application 17/580,879 is a continuation in part of application No. 16/402,611, filed on May 3, 2019, granted, now 11,437,250.
Application 16/402,611 is a continuation in part of application No. 16/287,658, filed on Feb. 27, 2019, granted, now 10,982,335, issued on Apr. 20, 2021.
Claims priority of provisional application 63/151,579, filed on Feb. 19, 2021.
Claims priority of provisional application 62/767,808, filed on Nov. 15, 2018.
Prior Publication US 2022/0148882 A1, May 12, 2022
Int. Cl. H01L 21/306 (2006.01); H01L 21/3213 (2006.01)
CPC H01L 21/30604 (2013.01) [H01L 21/32134 (2013.01); H01L 21/32133 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A method of etching a substrate using a hybrid atomic layer etching (ALE) process, the method comprising:
receiving the substrate, the substrate having a material exposed; and
selectively etching the material by performing multiple cycles of the hybrid ALE process, wherein each cycle comprises:
a) performing a gas-phase surface modification step to chemically modify an exposed surface of the material and provide a self-limited modified surface layer on the material, wherein the gas-phase surface modification step includes exposing the substrate to a gas-phase oxidizing reactant to oxidize the exposed surface of the material and form a self-limited oxidized layer on the material via a self-limiting oxidation reaction, and wherein the self-limited oxidized layer is a passivation layer formed on the material; and
b) performing a liquid-phase dissolution step to selectively dissolve the self-limited oxidized layer of the material, wherein the liquid-phase dissolution step includes dispensing one or more liquid-phase reactants onto a surface of the substrate to dissolve the self-limited oxidized layer, wherein said dispensing the one or more liquid-phase reactants comprises dispensing a complexing agent dissolved in a first liquid solvent onto the surface of the substrate, and wherein the complexing agent binds to the self-limited oxidized layer to form a complex-bound modified surface layer on the material;
wherein the one or more liquid-phase reactants are dispensed onto the surface of the substrate while the substrate is exposed to the gas-phase oxidizing reactant;
wherein the one or more liquid-phase reactants partition the gas-phase surface modification step and the liquid-phase dissolution step by displacing the gas-phase oxidizing reactant from the surface of the substrate;
wherein the self-limited oxidized layer formed via the self-limiting oxidation reaction forms the passivation layer on the material that prevents further oxidation of the exposed surface of the material before the one or more liquid-phase reactants are dispensed onto the surface of the substrate; and
wherein steps a)-b) are repeated one or more times until a desired amount of the material is removed from the substrate.