Atmospheric Pressure Plasma Jet-Assisted Synthesis of Zeolite-Based Low-k Thin Films

Abstract

Zeolites are ideal low-dielectric constant (low-k) materials. This paper reports on a novel plasma-assisted approach to the synthesis of low-k thin films comprising pure-silica zeolite MFI. The proposed method involves treating the aged solution using an atmospheric pressure plasma jet (APPJ). The high reactivity of the resulting nitrogen plasma helps to produce zeolite crystals with high crystallinity and uniform crystal size distribution. The APPJ treatment also remarkably reduces the time for hydrothermal reaction. The zeolite MFI suspensions synthesized with the APPJ treatment are used for the wet deposition to form thin films. The deposited zeolite thin films possessed dense morphology and high crystallinity, which overcome the trade-off between crystallinity and film quality. Zeolite thin films synthesized using the proposed APPJ treatment achieve low leakage current (on the order of 10 A/cm) and high Young's modulus (12 GPa), outperforming the control sample synthesized without plasma treatment. The dielectric constant of our zeolite thin films was as low as 1.41. The overall performance of the low-k thin films synthesized with the APPJ treatment far exceed existing low-k films comprising pure-silica MFI.

Zeolite-Based Antifogging Coating via Direct Wet Deposition

“…These results are in good agreement with their UV-vis spectra, in which interference was associated with the relatively smooth coatings of MFI-3 h, MFI-4.5 h, and MFI-5 h. The difference in surface morphology among the four sets of samples can be attributed to the crystallinity of the nanoparticles. The presence of amorphous nanoparticles in the suspensions of MFI-3 h, MFI-4.5 h, and MFI-5 h may explain why the resulting thin films were denser than those of MFI-6 h. A similar finding was reported in a previous study …”

“…The opaqueness of suspensions increased with the duration of the hydrothermal reaction, due to the formation and growth of zeolite MFI crystals. MFI-3 h samples were highly transparent, which suggests that low-crystallinity colloids were present in the solutions . Conversely, MFI-6 h samples were strongly opaque, which suggests the presence of high-crystallinity zeolite MFI.…”

“…76 To demonstrate the effectiveness of direct wet deposition in the casting of zeolite-based AF layers on a glass substrate, we casted pure silica zeolite MFI films on the glass substrate. According to our previous studies of wet deposition of various types of zeolites, [71][72][73][74]76 the pure silica MFI films presented the highest uniformity. Transmission electron microscopy (TEM) was used to image the zeolite MFI particles in the cast suspensions.…”

“…Instead, it uses stabilized zeolite colloidal solutions, in which the growth of zeolite crystals has been terminated. These cast suspensions are applied via spin-on deposition − or ultrasonic nozzle spray deposition …”

Microplasmas for Advanced Materials and Devices

“…Microplasmas effectively overcome this problem and facilitate the formation of nitride‐based NSs including titanium nitride (TiN) NPs and aluminum nitride (AlN) NPs from suitable precursors. Interestingly, emerging materials such as low‐dielectric constant (low‐k) zeolites thin films composed with zeolite particles with uniform size distribution and high crystallinity can be fabricated by nitrogen microplasmas at ambient pressure …”