Electrical properties of Bi2Mg2∕3Nb4∕3O7 (BMN) pyrochlore thin films deposited on Pt and Cu metal at low temperatures for embedded capacitor applications

Abstract

200 - nm -thick BMN films were deposited on Pt∕TiO2∕SiO2∕Si and Cu∕Ti∕SiO2∕Si substrates at various temperatures by pulsed laser deposition. The dielectric constant and capacitance density of the films deposited on Pt and Cu electrodes show similar tendency with increasing deposition temperature. On the other hand, dielectric loss of the films deposited on Cu electrode varies from 0.7% to 1.3%, while dielectric loss of films on Pt constantly shows 0.2% even though the deposition temperature increases. The low value of breakdown strength in BMN films on Pt compared to films deposited on Cu electrode was attributed to the increase of surface roughness by the formation of secondary phases at interface between BMN films and Pt electrodes.

Flexible Dielectric Bi1.5Zn1.0Nb1.5O7 Thin Films on a Cu‐Polyimide Foil

“…2(d)) confirmed the crystallites in the film. The as‐deposited AD–BZN films studied here were comprised of nanocrystallites with a high density and were therefore expected to show dielectric properties superior to those of the as‐deposited amorphous BZN films fabricated by other thin‐film processes such as sputtering or pulsed laser deposition (PLD) 6–8 . Furthermore, the AD–BZN films on the Cu/PI foil can be directly applied to the copper clad laminate of rigid/flexible PCB applications because all processes are conducted at RT.…”

“…High dielectric oxide thin/thick films on a metal foil are of particular interest for microelectronic applications integrated into electronic packaging, an approach that is currently receiving considerable attention due to cost and space advantages 2–4 . In addition to cost reduction, the required circuit board area is greatly reduced by replacing the surface mount components with preembedded capacitor layers, which offers advantages for electronic miniaturization and portability 3–8 . Furthermore, devices with embedded capacitor layers exhibit more reliable performance due to their decreased number of interconnects, which minimizes the parasitic noise.…”

“…Furthermore, devices with embedded capacitor layers exhibit more reliable performance due to their decreased number of interconnects, which minimizes the parasitic noise. As a metal electrode for flexible substrates, a Cu foil is attractive for thin or thick dielectric film deposition due to its low cost and high conductivity 6–8 . However, the utilization of Cu foils as film substrates poses critical problems because Cu is easily oxidized at high temperatures, which necessitates controlling the oxygen partial pressure to avoid Cu oxidization 3,4,6–8 .…”

“…As a metal electrode for flexible substrates, a Cu foil is attractive for thin or thick dielectric film deposition due to its low cost and high conductivity 6–8 . However, the utilization of Cu foils as film substrates poses critical problems because Cu is easily oxidized at high temperatures, which necessitates controlling the oxygen partial pressure to avoid Cu oxidization 3,4,6–8 . In addition, the ferroelectric films that have recently been widely investigated for application to high‐permittivity materials usually need to be postannealed at a high temperature to obtain high permittivity 3,4 .…”

“…Recently, paraelectric bismuth–zinc (magnesium)–niobate (BZN)–based thin films have attracted interest for embedded capacitor applications because they show a good dielectric constant (150–220) and leakage current performance even when fabricated at a low temperature 5–13 . Furthermore, BZN films show a large electric field dependence of their dielectric permittivity 9–13 .…”