US 12,327,726 B2
Wet-dry bilayer resist dual tone exposure
Anton J. Devilliers, Clifton Park, NY (US)
Assigned to Tokyo Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on May 3, 2022, as Appl. No. 17/735,707.
Claims priority of provisional application 63/183,129, filed on May 3, 2021.
Claims priority of provisional application 63/183,130, filed on May 3, 2021.
Claims priority of provisional application 63/183,128, filed on May 3, 2021.
Prior Publication US 2022/0351966 A1, Nov. 3, 2022
Int. Cl. H01L 21/027 (2006.01); G03F 7/00 (2006.01); G03F 7/09 (2006.01); H01L 21/311 (2006.01)
CPC H01L 21/0276 (2013.01) [H01L 21/0274 (2013.01); H01L 21/31133 (2013.01); H01L 21/31138 (2013.01); H01L 21/31144 (2013.01); G03F 7/094 (2013.01); G03F 7/70466 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of patterning a substrate, the method comprising:
forming a multilayer photoresist stack on a substrate, the multilayer photoresist stack comprising a first layer of a wet photoresist deposited by spin-on deposition, and a second layer of a dry photoresist deposited by vapor deposition, the first layer positioned over the second layer; and
exposing the multilayer photoresist stack to a first pattern of actinic radiation which includes relative, spatially-varying doses of actinic radiation, the first pattern of actinic radiation including high-dose regions, mid-dose regions and low-dose regions,
wherein the multilayer photoresist stack and the first pattern of actinic radiation are configured such that after the exposing the multilayer photoresist stack to the first pattern of actinic radiation,
in the high-dose regions, developability of both the first layer and the second layer is changed,
in the mid-dose regions, developability of the first layer is changed while developability of the second layer is unchanged, and
in the low-dose regions, developability of both the first layer and the second layer is unchanged.
 
19. A method of patterning a substrate, the method comprising:
forming a multilayer photoresist stack on a substrate, the multilayer photoresist stack including a dry photoresist layer deposited by vapor deposition, and a wet photoresist layer deposited by spin-on deposition, the wet photoresist layer positioned over the dry photoresist layer; and
exposing the multilayer photoresist stack to a pattern of actinic radiation, the pattern of actinic radiation including differing relative doses of actinic radiation at spatial locations on the substrate include high-dose regions, mid-dose regions and low-dose regions,
wherein a composition of the multilayer photoresist stack is selected such that as a result of exposure to the pattern of actinic radiation,
in the high-dose regions, developability of both the dry photoresist layer and the wet photoresist layer is unchanged,
in the mid-dose regions, developability of the wet photoresist layer is changed while developability of the dry photoresist layer is unchanged, and
in the low-dose regions, developability of both the dry photoresist layer and the wet photoresist layer is changed.