US 12,411,412 B2
Patterning semiconductor features
Michael Murphy, Albany, NY (US); Charlotte Cutler, Albany, NY (US); and David Conklin, Saratoga Springs, NY (US)
Assigned to Toyko Electron Limited, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Nov. 22, 2022, as Appl. No. 17/992,522.
Prior Publication US 2024/0168384 A1, May 23, 2024
Int. Cl. G03F 7/16 (2006.01); G03F 7/00 (2006.01); G03F 7/30 (2006.01); G03F 7/38 (2006.01); G03F 7/40 (2006.01)
CPC G03F 7/168 (2013.01) [G03F 7/0035 (2013.01); G03F 7/30 (2013.01); G03F 7/38 (2013.01); G03F 7/40 (2013.01)] 21 Claims
OG exemplary drawing
 
1. A method, comprising:
depositing a first overcoat film on a semiconductor wafer, the semiconductor wafer comprising first patterned features of a photoresist layer, the first patterned features comprising first photoresist structures and first recesses defined by the first photoresist structures, the first overcoat film filling the first recesses and covering the first photoresist structures, the first recesses having first widths that are greater than a target width;
baking the semiconductor wafer to form soluble portions of the first photoresist structures;
selectively removing the first overcoat film;
depositing a second overcoat film that fills the first recesses and covers the first photoresist structures;
developing the semiconductor wafer to remove portions of the second overcoat film to reveal and remove the soluble portions of the first photoresist structures to define second patterned features that comprise second photoresist structures, first overcoat structures interspersed between the second photoresist structures, and second recesses defined by the second photoresist structures and the first overcoat structures;
executing a solubility-changing process to cause the first overcoat structures to become insoluble for development;
depositing a third overcoat film that fills the second recesses and covers the second photoresist structures and the first overcoat structures;
baking the semiconductor wafer to form soluble portions of the first overcoat structures; and
developing the semiconductor wafer to remove the third overcoat film and the soluble portions of the first overcoat structures to define third patterned features that comprise third photoresist structures, second overcoat structures interspersed between the third photoresist structures, and third recesses defined by the second overcoat structures and the third photoresist structures, wherein the second overcoat structures have the target width.