A facile route for the fabrication of large-scale gate-all-around nanofluidic field-effect transistors with low leakage current

Abstract

Active modulation of ions and molecules via field-effect gating in nanofluidic channels is a crucial technology for various promising applications such as DNA sequencing, drug delivery, desalination, and energy conversion. Developing a rapid and facile fabrication method for ionic field-effect transistors (FET) over a large area may offer exciting opportunities for both fundamental research and innovative applications. Here, we report a rapid, cost-effective route for the fabrication of large-scale nanofluidic field-effect transistors using a simple, lithography-free two-step fabrication process that consists of sputtering and barrier-type anodization. A robust alumina gate dielectric layer, which is formed by anodizing sputtered aluminium, can be rapidly fabricated in the order of minutes. When anodizing aluminium, we employ a hemispherical counter electrode in order to give a uniform electric field that encompasses the whole sputtered aluminium layer which has high surface roughness. In consequence, a well-defined thin layer of alumina with perfect step coverage is formed on a highly rough aluminium surface. A gate-all-around nanofluidic FET with a leak-free gate dielectric exhibits outstanding gating performance despite a large channel size. The thin and robust anodized alumina gate dielectric plays a crucial role in achieving such excellent capacitive coupling. The combination of a gate-all-around structure with a leak-free gate dielectric over a large area could yield breakthroughs in areas ranging from biotechnology to energy and environmental applications.

Fundamental Studies of Nanofluidics: Nanopores, Nanochannels, and Nanopipets

“… 25 Nanoapertures are also produced by a low cost, corner lithography technique in which isotropic thinning generates a nitride nanodot which is removed to form a nanoscale opening. 26 Nanoporous materials such as anodized aluminum oxide 27 can be modified by atomic layer deposition to effectively reduce pore diameters 28 and increase performance. 29 …”

Micro/Nanofluidic‐Enabled Biomedical Devices: Integration of Structural Design and Manufacturing

“…Figure 6B shows another approach by fabricating nanochannels directly on synthesized nanoporous material. [ 82 ] Electrosputtering is applied on porous alumina membrane to form gate metal layers, and subsequently performing barrier‐type anodization to form a gate dielectric layer. Nanofluidic field‐effect transistors (FETs) are thus fabricated and potentially applied for DNA sequencing, drug delivery, etc.…”

Low Cost and Simple PMMA Nozzle Fabrication by Laser Cutting and PDMS Curing Bonding

“…Thermoplastic polymer such as PMMA, PC (Polycarbonate), and COC (Cyclic Olefin Copolymers) can also be used for nozzle fabrication [17,18]. Hot embossing and thermal nano-imprinting are typical methods to pattern the structures into those thermoplastic polymer [19,20]. Similar with UV photolithography, the above 2 methods also need an extra mold.…”