UV flood exposure sources provide quick, non discriminant processing of UV-sensitive materials and substrates. This can be incredibly useful when a sample doesn’t require more than one mask, or it’s an abnormal shape or size.  

Photolithography is a technique that transfers a pattern from a photomask to a substrate coated with a light-sensitive material called photoresist. The pattern is created by exposing the photoresist to light from a source through the mask, and then developing it in a solution. The substrate can then undergo other processes such as deposition or etching. Some devices may require multiple photolithography steps with different masks, which need to be aligned precisely to the previous layers. For this purpose, mask aligners are used to ensure accuracy and control the exposure conditions.

Nanoimprint lithography uses a transparent mould to deform a layer of photoresist into a desired topography. Light is then passed through the clear mould to cure the resist and make these deformations permanent. This technique relies on the accuracy of the mould but can be used to create many identical versions of the same structure.

Lamination is a microfabrication technique used to create precise, layered structures on substrates like semiconductors, MEMS devices, and microfluidic chips. It combines photolithography with lamination to achieve high-resolution patterning and structural integrity.

Microcontact printing (µCP) and microtransfer printing are advanced techniques used to create precise patterns and structures at the micro and nanoscale. These methods are part of the broader category of soft lithography, which utilises elastomeric stamps to transfer materials onto substrates.

Polydimethylsiloxane (PDMS) is widely used to create a low-cost micro-structured mould for microfluidic applications. PDMS is an incredibly well behaved material under a variety of conditions, it’s biocompatible and is very easy to fabricate.

Spin coaters are capable of applying uniform thickness polymer films, such as a resist to substrates. Resist is essential for many types of lithography, such as UV lithography. Resists are termed either positive or negative — this denotes whether, when cured, chemical bonds are made or broken, and therefore whether the sections of resist that remain are either the true pattern, or it’s inverse. This selection must be considering etching or deposition stages that may follow as it will help to make.

Cleaning, an essential step when operating on the micro and nanoscale, is used to remove contaminants from the surface of the substrate before it is used in another fabrication process. This can be achieved through various methods, including the use of an ultrasonic bath or an asher. Ultrasonic baths use high-frequency sound waves to agitate a cleaning solution, effectively removing contaminants from the substrate surface. Ashers, on the other hand, use heat to remove unwanted material, such as photoresist. Both methods are often used to clean wafers, although ashers can also be used to selectively etch away material.

Focused Ion Beam (FIB) milling provides significant advantages as a single-step, nanoscale prototyping method that doesn’t require a mask or resist. It is capable of performing: subtractive lithography in which atoms are locally milled away by physical sputtering with sub-10nm resolution; additive lithography in which materials are locally deposited with sub-10nm resolution; local ion implantation for fabrication of an etching mask for subsequent pattern transfer; and direct material modification by ion-induced mixing. FIB milling is a versatile technique with a wide range of applications including advanced materials development/characterisation; resist-free, high-resolution patterning of nanostructures; cross-sectional analysis of samples; sample preparation for transmission electron microscopy (TEM) and for atom probe analysis.

Maskless lithography can be used to speed up the lithography process, and to save money by negating the need to fabricate steps required. Micropatterning is a lithography process that involves an image being projected directly onto a photoresist without the use of a mask.

He Ion Microscopy(HIM) combines milling of samples along with imaging at sub-nanometre resolution. Ion microscopy is a type of microscopy that uses a beam of ions (charged atoms or molecules) to image the surface or the interior of a sample. Ion microscopy can achieve high resolution, high sensitivity, and high depth of field.

Laser processing uses a highly controlled and focused beam of high-energy photons of the same wavelength to burn away material. These processes are repeatable, scalable and cheap, but can induce thermal stresses on the substrate, and resolutions tend to be in the micrometre regime. Laser processing is often used within ANFF to create masks for later lithography steps, but it can also be used to create patterns directly into the substrate itself, skipping several ordinary fabrication steps.

Electron Beam Lithography (EBL) allows users to write patterns with extremely high resolution, smaller than 10nm in size. It makes use of a highly energetic, tightly focused electron beam, which is scanned over a sample coated with an electron-sensitive resist. The electron beam scans the image according to a pattern defined on a CAD file. The sample is then developed in an appropriate solvent which reveals the structures defined into the resist. This acts as a mould for subsequent pattern transfer techniques such as dry etching or metal lift-off. Due to the high-resolution nature of the technique, EBL has a vast range of applications including nano-electronics, photonics, plasmonics, nano-fluidics, MEMS, x-ray and neutron optics.

Thermal Scanning Probe Lithography (t-SPL) is a 3D direct-write lithography technique that provides sub-10nm resolution with sub-2nm vertical accuracy in ambient conditions. A 1,000°C cantilevered tip sublimates PPA resist as it scans over a sample, before the tip quickly cools to provide real-time topological AFM-type characterisation. The process isn’t reliant on an ion gun or electron beam (helpful when processing sensitive materials); it operates at ambient temperature, pressure, low voltage, and under N2 atmosphere instead of requiring a specialist environment. The ease of use and high resolution means it is ideal for rapid fabrication of three-dimensional nanostructures including the fabrication of novel devices and components for nanophotonics, nanooptics, nanoelectronics, and plasmonics applications.

Hot embossing is a pattern-transfer technique, involving the application of pressure and heat to a polymeric or resist-coated substrate, placed in contact with a master mould. This allows the relief features on the mould to be transferred faithfully. Hot embossing achieves fast patterning at a resolution of 50nm.This technique addresses a wide range of applications, from polymer-based lab-on-chip systems, where imprinting is performed on thick polymers substrates, for the fabrication of sub 50nm features for bio-sensing or data recording applications, as well as microfluidics, MEMS, optoelectronics, packaging and SOI production.