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Conquering the Low‐ k Death Curve: Insulating Boron Carbide Dielectrics with Superior Mechanical Properties
Author(s) -
Nordell Bradley J.,
Nguyen Thuong D.,
Keck Christopher L.,
Dhungana Shailesh,
Caruso Anthony N.,
Lanford William A.,
Gaskins John T.,
Hopkins Patrick E.,
Merrill Devin R.,
Johnson David C.,
Ross Liza L.,
Henry Patrick,
King Sean W.,
Paquette Michelle M.
Publication year - 2016
Publication title -
advanced electronic materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.25
H-Index - 56
ISSN - 2199-160X
DOI - 10.1002/aelm.201600073
Subject(s) - materials science , dielectric , boron carbide , amorphous solid , boron , low k dielectric , composite material , semiconductor , interconnection , optoelectronics , crystallography , chemistry , organic chemistry , computer network , computer science
To enable the continued scaling of integrated circuits, the semiconductor industry faces ongoing struggles to implement better low‐dielectric‐constant (low‐ k ) materials within the interconnect system. One of the biggest challenges to integrating new dielectrics is overcoming the low‐ k death curve—that is, the fatal falloff in mechanical properties associated with the low material densities required to achieve low k values. It is shown that amorphous hydrogenated boron carbide (a‐BC:H) films exhibit Young's modulus ( E ) values between two and ten times greater than those of state‐of‐the‐art Si‐based dielectric materials across a wide range of k values. In particular, optimized a‐BC:H films with moderate k values in the range of 3–4, in addition to possessing outstanding stiffness ( E ≈ 100–150 GPa), simultaneously exhibit excellent electrical properties (leakage current of <10 –8 A cm –2 at 2 MV cm –1 and breakdown voltage of >5 MV cm –1 ). Films in this range also demonstrate resistance to Cu diffusion to at least 600 °C, as well as chemical stability and etch properties suitable for low‐ k diffusion barrier/etch stop applications.