Lithography & Patterning

Installation 1

Lithography and nanopatterning installation is devoted to the top-down patterning of materials covering from nanostructured surfaces (patterning of nanomaterials, nanopatterning of materials) to advanced micro-nano devices of interest (sensor, electronic, magnetic probes, microfluidics, etc.) and advanced functional sample environments for in-operando characterization. Standard lithography and nanolithography tools such as UV-lithography, e-beam lithography (EBL), focused ion beam (FIB) as well as unique or rare in-house tools such as Extreme ultraviolet interference lithography or synchrotron X-ray lithography are available, to be combined with pattern transfer tools by physical and chemical processes.

Please be reminded that physical masks for photolithography should be provided by the user. Since they are usually fabricated by third-party photolithographic mask vendors, you will be asked to interact with the host technicians to ensure that they will be compatible with the photolithografic tools of the assigned installation. Similarly, electronic files for direct writing approaches provided by you should be checked by the host technicians to assure their appropriateness.

Important note: Building test structures or making a device around a functional (nano) material may require additional iterations of growth/deposition and litho/patterning steps of ancillary materials (e.g. defining metal electrodes). Techniques similar to the ones reported for Installations 1 & 2 together with others like sputtering/evaporation may be used to define ancillary structures by lithography followed by dry or wet patterning processes. To avoid burdening in excess the catalogue and the evaluation process, not all such processes are listed. Please, make sure that your needs in relation to such ancillary elements are contained in the description of your proposal. TLNet will figure out if a process sequence fitting your purposes can be established within NFFA.

EBL Electron Beam Lithography

Electron-beam lithography is a nanopatterning technique utilizing a very well-focused electron beam in order to write nanoscale patterns directly on special e-beam resists. A variety of powerful techniques is provided for the lateral as well as three-dimensional pattern transfer with resolutions down to 10 nm. Compared to other nanostructuring methods, it stands out for a high level of flexibility and resolution and reasonable patterning speed.

FIB Focused Ion Beam
By FIB, usually combined with an electron column, it is possible to achieve nanometric structures, either by ion milling or by ion/electron beam disposition. In such systems 2D and 3D nanostructures can be fabricated, with a high degree of control and flexibility. With nanomanipulators electrical measurements are possible, as well as characterization when combined with different detectors. It is a good technique for TEM lamellae sample preparation. preparation for subsequent TEM investigations.
UVL Ultra Violet Lithography
Ultraviolet lithography also known as optical or photolithography is the most commonly used patterning technique in microfabrication. A photosensitive material (photoresist) is spin-coated onto the substrate to be patterned. The photoresist is illuminated with UV light through a photomask which contains the relevant geometric patterns. The pattern is transferred on the photoresist, after the required development of the exposed sample.
UV/EUV-IL Ultra Violet/Extreme UV - Interference lithography

EUV interference lithography is a powerful tool both for scientific and industrial research. A spatially filtered beam from the synchrotron is projected on a mask through multiple gratings. The diffracted beams interfere on a wafer coated with a photosensitive polymer. The tool can be used to develop novel high-resolution resists but also as a high resolution and throughput patterning technique (fabrication in parallel, sub 10 nm resolution).

Two-photon Lithography
High resolution 2D and 3D structuring process of a photosensitive material by means of physical and chemical changes produced in the focusing area of an ultrashort pulse laser of sufficiently high light intensity. 2D resist mask-less patterns, or polymeric micro-parts with a 3D shape can be obtained by scanning the photoresist relative to the beam focus submicron. Features of a few hundred of nm are possible in working areas of 1 cm2, which can be patched.
NIL NanoImprint Lithography

NIL is a low cost, high resolution and high-throughput method for nanoscale patterning. It is a simple nanolithography process that creates patterns by mechanical deformation of an imprint resist and subsequent processes. Nanoimprint lithography has demonstrated to be one of the most promising next generation techniques for large area replication in the nanometer scale. Thermal and UV assisted NIL is possible.

XRL X-Ray Lithography
XRL, by using Synchrotron X-rays, is a reliable and simple mean of replicating patterns of arbitrary geometry. A wide energy spectrum selection allows the patterning of both very thick resist (up to 1mm) with aspect-ratio greater than 40, or alternatively, high resolution down to feature sizes of 40nm. Peculiar is the possibility to perform inclined multi-exposures.
DXRL Deep X-Ray Lithography
Deep X-ray Lithography allows controlled irradiation of samples with high energy X-rays (2–20 keV). It offers high penetration depth, minimum lateral resolution of 200 nm, high aspect ratio, vertical sidewalls, optical surface quality. It is used to produce microdevices directly made of plastic, or of other materials following the LIGA process (lithography, electrodeposition, moulding). DXRL can also be employed for radiation assisted synthesis and processing of novel materials.
AFML Atomic Force Microscopy Lithography (from Sept 2017)

In AFM short range tip-sample interactions provide insight into phenomena which take place at the surface: catalysis, friction, low dimensional magnetism, quantum properties of single atom and single molecules, etc… The knowledge gained is also used to modify the surface in a controlled way to create nanometer scale patterns. Contrary to other lithography approaches, it can provide a true 3D reconstruction of the patterns during the fabrication process.

RIE Reactive Ion Etching

RIE is used to etch various materials under vacuum in the presence of reactive ions. It is a simple and relatively economical solution for dry etching. The sample to be etched is placed in a vacuum chamber and gas is injected into the process chamber via a gas inlet in the top electrode. The lower electrode is negatively biased and a single RF plasma source determines both the ion density and their energy.

ICP Inductively Coupled Plasma
ICP is a reactive ion etching technique (dry etching), where plasma is generated by means of inductively coupling RF power in the source. The ion energy bombarding the substrate is independently controlled via the applied bias power. This independent control allows for a wide process space to address various requirements from anisotropic deep etching to highly chemical or physical processes.
Chip packaging

At the end of the manufacturing when the components must be tested or used singularly,. It provides the device with a mechanical body, environment protection, thermal heat sinking and electrical connection to the real world. It encompasses dicing individual dies with automatic diamond saws, die attach with epoxies of different thermo-mechanical properties to packages of appropriate size and contact pads number, and chip-to-package wire bonding (wedge, bond and ribbon).

Electrochemical deposition

A metal coating to a metallic or another conducting surface can be applied by means of an electrochemical process. A current is passed from an anode to a cathode through an electrolyte causing the dissociated metal ions to gain electrons and oxidize on the surface of the cathode (surface to be coated), thereby forming a metallic coating.

I & g-line steppers
Geometric patterns in a photo-mask are transferred to a substrate. Mask aligners project in a single UV shot the full wafer design. On the other hand, steppers project a single chip onto the substrate in a step and repeat sequence. In this way better resolutions (around half micron) and better local alignment with previous patterns are achieved. The maximum chip size ranges between 1.5 and 2.2 cm per side. It can only work with full wafers (100 or 150 mm).
t-SPL Thermal Scanning Probe Lithography

Thermal scanning probe lithography is a mask-less, serial and direct-write lithography technique, where a cantilever with a heatable ultra-sharp silicon tip (which is only a few nanometers in diameter) is brought into contact with a special resist that is spin-coated on a substrate. The technique can be used to create sub-10 nm structures as well as complex, high resolution 3D shapes.

3d laser manufacturing
Laser sintering is a well know technology for 3D printing. A powder polyamide is sintered layer-by-layer using a laser. The result is a 3D object completely functional with better physical properties than the corresponding injection-molded version of it. It is not a technique for fabricating the devices themselves, but auxiliary pieces or holders where the devices may be encased.
Ion implantation

It is the kinetic insertion of electromagnetically accelerated ions into substrates to change the physical, chemical, or electrical properties of the sample. For instance, it is one of the ways how extra dopants are introduced in silicon substrates. Different elements such as B, P, As, Si, N, H, Ar, Ge, Mg, Al, Cl can be implanted. Small pieces can be processed.