11.40-12.00 | Room 4
Chairs: Gertjan Koster & Muharrem Bayraktar
11.40 -12.00 | Piezo-MEMS and industry: Minh Nguyen (Lam Research): High-Volume AlScN Piezoelectric Thin Film Manufacturing using Pulsed Laser Deposition
Minh Nguyen and Matthijn Dekkers
Lam Research International B.V., Auke Vleerstraat 3, 7521 PE, Enschede, The Netherlands
E-mail: Minh.DucNguyen@lamresearch.com
Pulsed laser deposition (PLD) is a very versatile thin film deposition technology that has the ability to deposit a wide-range of advanced thin film materials. With today’s market demand for enhanced and new material systems, PLD enables layers that cannot practically be deposited by conventional technologies like sputtering physical vapor deposition (PVD-sputtering). PLD technique enables more advanced device-design and is driving the next-generation of radio-frequency (RF) filters for 5G, WiFi 6/6E, high-end micro-electromechanical systems (MEMS), ferroelectric memory and photonics applications.
For piezoelectric Aluminum Scandium Nitride, PLD has extended the limits of Sc-substitution in the AlScN films, resulting in ultrahigh piezoelectric properties.
Additionally, this PLD platform enables precise control over film-thickness uniformity and film-stress, which are crucial for high-yield RF-MEMS applications. For the first time in semiconductor production, Lam Research is using pulsed-lasers to deposit thin films and bringing PLD to wafer-level mass production. Lam Research PLD is expected to be key in developing cutting-edge specialty technologies devices, such as RF filters for 5G and Wi-Fi 6/6E and high-end MEMS micro.
12.00 – 12.20 | Yasser Pordeli (S&T, ANP, AQO) From Stress to Success: >1 µm Thick Silicon Nitride on Sapphire for PICs
Stoichiometric silicon nitride (Si₃N₄) is a key material for integrated photonics. However, conventional fabrication routes using silicon substrates are limited to Si3N4 thicknesses of ca. 400 nm due to the high tensile residual stress in the films. Sapphire provides a promising alternative substrate, enabling the realization of >1 µm thick Si₃N₄ waveguides using a single-step low pressure chemical vapor deposition (LPCVD) process. This platform creates new opportunities for highly confined photonic circuits, nonlinear optics, mid-infrared applications, and dispersion engineering. The presentation will highlight the fabrication concept, the main process challenges encountered so far, and the steps currently being taken toward optical characterization of the platform. It will address both front-end and back-end fabrication challenges. Overall, these developments aim to establish thick Si₃N₄ on sapphire as a practical platform for next-generation integrated photonics.
12.20 – 12.40 | Roberto Andrade (S&T, MST, MSUS) Nanoparticles as Sacrificial Pore Fillers for the Fabrication of High Permeability Polyelectrolyte Multilayer Membranes
Polyelectrolyte multilayer (PEM) membranes have emerged as a versatile and sustainable option for separation processes. Their fabrication at ambient conditions and from aqueous solutions also makes them attractive from a green chemistry and scalable manufacturing perspective. However, they remain constrained by the classic permeability–selectivity trade-off, especially as PEM is coated on a porous support, a certain thickness of the multilayer is required to close all pores and avoid defects. In this study, we introduce a novel approach to overcome this constrain. Here, we introduce silica (SiO₂) nanoparticles as sacrificial pore fillers to overcome this structural limitation. The nanoparticles are incorporated in the first PDADMAC/PSS bilayer to temporarily occupy the support pores, preventing the polyelectrolyte to enter the pores. Once a continuous PEM layer is formed, the nanoparticles are dissolved in a high pH solution, leaving behind a thinner PEM active layer. This sacrificial nanoparticle approach effectively doubles the permeability while even slightly improving the molecular weight cut-off. Donnan exclusion remains the dominant separation mechanism. These findings demonstrate that sacrificial nanoparticle approach can break the traditional permeability–selectivity barrier, enabling low-energy, high-efficiency membrane separations and advancing the next generation of energy-conscious separation technologies.
12.40 – 13.00 | Bas Haartsen (S&T, NEM, PIN) Structure and Ageing of Silica-Coated Aluminium Pigments
Silica-coated aluminium pigments combine metallic reflectivity with corrosion resistance. However, nanoscale shell defects may allow water penetration through their silica shell during storage. Here, we used TEM, EDX, EELS, and KPFM to compare pristine pigments with pigments aged for 48 days in an aqueous medium. We found that pristine (fresh) pigments have a shell thickness of about 15 nm and a homogeneous surface potential. After ageing, the shell thickness decreased to about 6 nm, with oxidation and aluminium depletion concentrated near the pigment edges. EELS confirmed the formation of aluminium oxide, while KPFM showed increased surface-potential heterogeneity. These findings indicate that edge-localised shell degradation enables water penetration and corrosion of the aluminium core. This degradation may reduce optical performance, destabilise the pigment suspension, and reduce the reliability of metal-flake printing.