US 12,341,009 B2
Variable hardness amorphous carbon mask
Shihsheng Chang, Albany, NY (US); Andrew Metz, Albany, NY (US); Yun Han, Albany, NY (US); Ya-Ming Chen, Austin, TX (US); Kai-Hung Yu, Albany, NY (US); and Eric Chih-Fang Liu, Albany, NY (US)
Assigned to TOKYO ELECTRON LIMITED, Tokyo (JP)
Filed by Tokyo Electron Limited, Tokyo (JP)
Filed on Apr. 21, 2022, as Appl. No. 17/660,111.
Prior Publication US 2023/0343592 A1, Oct. 26, 2023
Int. Cl. H01L 21/033 (2006.01)
CPC H01L 21/0332 (2013.01) 20 Claims
OG exemplary drawing
 
1. A method of fabricating an amorphous carbon layer (ACL) mask, the method comprising:
forming an ACL on an underlying layer, the ACL comprising a soft ACL portion having a first hardness less than 10 GPa that is underlying a hard ACL portion having a second hardness greater than or equal to 10 GPa;
forming a patterned layer over the ACL; and
forming an ACL mask by etching through both the soft ACL portion and the hard ACL portion of the ACL to expose the underlying layer using the patterned layer as an etch mask.
 
9. A method of fabricating an amorphous carbon layer (ACL) mask, the method comprising:
depositing a soft ACL layer of a multilayer ACL stack on an underlying layer, the soft ACL layer having a first hardness less than 10 GPa and a first thickness of at least 0.5 μm,
depositing a hard ACL layer of the multilayer ACL stack over the soft ACL layer, the hard ACL layer having a second hardness greater than or equal to 10 GPa;
forming a patterned layer over the multilayer ACL stack; and
forming an ACL mask by etching through the multilayer ACL stack to expose the underlying layer using the patterned layer as an etch mask.
 
14. A method of fabricating an amorphous carbon layer (ACL) mask, the method comprising:
forming an ACL on an underlying layer, the ACL comprising a soft ACL portion having a first hardness underlying a hard ACL portion having a second hardness greater than the first hardness, wherein forming the ACL comprises
continuously depositing the ACL beginning with the soft ACL portion at the underlying layer, and
varying processing conditions while continuously depositing the ACL to create a hardness gradient transitioning from the first hardness to the second hardness of the hard ACL portion at an upper surface of the ACL;
forming a patterned layer over the ACL; and
forming an ACL mask by etching through both the soft ACL portion and the hard ACL portion of the ACL to expose the underlying layer using the patterned layer as an etch mask.