US 12,217,968 B2
Atomic layer etching for smoothing of arbitrary surfaces
Harold Frank Greer, Pasadena, CA (US)
Assigned to CALIFORNIA INSTITUTE OF TECHNOLOGY, Pasadena, CA (US)
Filed by California Institute of Technology, Pasadena, CA (US)
Filed on Apr. 6, 2021, as Appl. No. 17/224,037.
Claims priority of provisional application 63/005,709, filed on Apr. 6, 2020.
Prior Publication US 2021/0313185 A1, Oct. 7, 2021
Int. Cl. H01L 21/306 (2006.01); H01L 21/3105 (2006.01); H01L 21/321 (2006.01); H01L 21/67 (2006.01); H01L 21/677 (2006.01)
CPC H01L 21/30604 (2013.01) [H01L 21/31055 (2013.01); H01L 21/32115 (2013.01); H01L 21/67075 (2013.01); H01L 21/67703 (2013.01); H01L 21/67739 (2013.01)] 28 Claims
OG exemplary drawing
 
1. An apparatus:
a reactor tool comprising a source of a reactant for reacting with a surface of a substrate so as to form a reactive layer on the substrate, wherein the reactant comprises is generated by a plasma, the substrate comprises a material comprising a semiconductor, a metal, or a dielectric, and the reactive layer comprises a chemical compound including the reactant and the material; and
an etching tool comprising a source of a liquid wet etchant for removing the chemical compound; and
a computer tool comprising a non-transitory computer readable medium storing a plurality of instructions, the plurality of instructions comprising:
outputting the reactant in the reactor tool,
transferring the substrate between the reactor tool and the etching tool, and
outputting the liquid wet etchant in the etching tool to remove the chemical compound at a higher rate than the material so as to smoothen the surface of the substrate and form the surface having a root mean square surface roughness of less than 1 nm.