| Title |
Influence of Substrate on the Mechanical Machining Characteristics of Copper Thin Films for Nano
/Micro Pattern Fabrication |
| Authors |
박아현(Ahyun Park,) ; 황해인(Hae-In Hwang) ; 조인호(In-Ho Jo) ; 이승훈(Seung-Hun Lee) ; 하지훈(Jihun Ha) ; 최민재(Min-Jae Choi) ; 김정환(Jeong Hwan Kim) |
| DOI |
https://doi.org/10.3365/KJMM.2025.63.9.735 |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Keywords |
Nano/micro pattern; Copper; Thin film; Machinability; Substrate effect; Mechanical property |
| Abstract |
As semiconductor devices continue to be scaled down, the demand for high-resolution and highprecision
patterning technologies has increased significantly. Nanomachining offers a promising
alternative to planar photolithography by enabling chemical-free processing, simplified fabrication steps,
and compatibility with curved or three-dimensional structures. While previous research has primarily
focused on bulk materials, studies on thin film-based nanomachining remain limited. In thin film
machining, the films are significantly thinner than the substrates and are thus strongly influenced by
the mechanical properties of the underlying substrate. To enable reliable and controllable patterning, it
is essential to understand how these substrate characteristics affect thin film machinability. In this
study, copper thin films were deposited on silicon and glass substrates and patterned using
nanomechanical machining under normal loads ranging from 2 to 16 mN. Despite the use of identical
film material, machining profiles varied significantly depending on the substrate. Notably, films on glass
substrates exhibited 8~9% greater machining depth than those on silicon, indicating that the underlying
substrate significantly affects machinability. Given the critical role of hardness in machinability,
nanoindentation analysis was conducted to evaluate the mechanical response of each film-substrate
system. The analyses revealed distinct hardness transitions from the intrinsic film hardness region (F)
to two composite hardness regions (C1 and C2), which closely corresponded to the changes in machining
behavior observed in the load-depth curves. These results demonstrate that the substrate influence plays
a critical role in determining the machinability of thin films, and affects both cutting behavior and
patterning outcomes. These findings provide fundamental insight into substrate-film mechanical
interactions and support the optimization of process conditions for reliable nanoscale patterning in
advanced electronics and device fabrication. |