US 11,798,837 B2
Methods for forming openings in conductive layers and using the same
Tsuyoshi Tomoyama, Hiroshima (JP); and Keisuke Otsuka, Okayama (JP)
Assigned to Micron Technology, Inc., Boise, ID (US)
Filed by Micron Technology, Inc., Boise, ID (US)
Filed on Oct. 1, 2021, as Appl. No. 17/491,825.
Prior Publication US 2023/0107365 A1, Apr. 6, 2023
Int. Cl. H01L 21/768 (2006.01); H10B 12/00 (2023.01)
CPC H01L 21/76811 (2013.01) [H10B 12/485 (2023.02); H10B 12/03 (2023.02)] 16 Claims
OG exemplary drawing
 
1. A method comprising:
forming a conductive layer;
forming a first hard mask on the conductive layer;
forming a second hard mask on the first hard mask;
providing a first opening through the first and second hard masks by lithography; and
removing a surface of the conductive layer under the first opening to provide a second opening in the conductive layer under the first opening, removing comprising applying one or more charged particle beams through the first opening,
wherein the first hard mask has hardness greater than hardness of the second hard mask.