NGI Cleanrooms: behind the masks, we’re open for business

Collaborations National Graphene Institute Research 15th October 2021

One of the many curiosities of interaction during the pandemic has been a tendency to meet people for the first time twice: once with a mask, seeing only eyes and hair, and then without-mask as the whole face is revealed. The two experiences are often revealingly different.

That duality pre-dates coronavirus at the National Graphene Institute (NGI) Cleanrooms, however, where full PPE has been a fact of daily, professional life since the facility opened in 2015. The need for controlled environments around the sensitive equipment required for nanoscale chemistry and engineering means in some cases the air is 1,000 times cleaner than in a hospital operating theatre. So head-to-toe coverings are a must to avoid contamination of the air by staff – and not, as it may appear, to protect the staff from airborne hazards.

To the uninitiated, images and video of lab workers dressed like this can seem impersonal, forbidding even. But behind the PPE is a vibrant community of scientists and technicians working at the nanoscopic edge of advanced materials science and making discoveries that will define the next century and more of technological advance and success for UK plc in innovation industries.

Dangers of dust and more

It’s worth reiterating at this point just how small we are talking, here. Some electronic devices made in the NGI are measured in 10s of nanometres or fewer (1 nanometre = 1 millionth of a millimetre). At that scale, a mote of dust big enough to be visible to the naked eye would crush a device like a large tree falling on your car.

“You need the air to be clean,” says Francisco Lopez-Royo, manager of the NGI Cleanrooms. “Here we have Class 100 and 1,000 rooms – which means you have fewer than 100 or 1,000 particles larger than half a micron in a cubic foot of air.”

And dust is not the only consideration; other intrusive elements, such as jewellery or perspiration, may also cause issues. “Certain metals – even at a few parts per million – can ruin devices. Gold, for example, disperses into silicon and creates additional energy levels. And sodium, which we carry on our skin, is also dangerous for certain devices, applications and products.”

Advanced materials hub

Fran is conducting a tour of the cleanrooms, split across two floors of the NGI, which is located on The University of Manchester’s south campus. The facility has recently been joined by two impressively sized neighbours in the new Henry Royce Institute for Advanced Materials Research and MECD, the Manchester Engineering Campus Development, which will house incoming Departments from the Faculty of Science and Engineering when north campus is vacated in 2022. It all adds up to an unparalleled concentration of expertise in material science at the home of graphene and 2D materials.

Enclosed in dark blue PPE, Fran outlines the atmospheric parameters for cleanroom operation, of which there are four: amount of particles in the air, temperature, humidity and air pressure, the pressure kept high so that if you open a door, or a seal leaks, the air goes out rather than coming in.

Or maybe five. “There is a fifth parameter – linked to the need to keep the air clean and to the cleanroom’s design – that you have to keep the air circulating very quickly,” says Fran. “In a typical office’s air conditioning, you would have something like 50 or 60 air changes per hour, to general office standards. In our cleanroom it’s between 250 and 350, depending on the classification.”

Challenging environment

These are quite challenging environments in which to work, so what are the skills and attributes that Fran looks for in a technician or engineer?

“I would say 75-80% of those attributes would be shared by any other laboratory. People who are technically-minded, proactive, self-starters who like fixing things and have good troubleshooting skills,” he says. “But particularly for cleanrooms, you’re looking for people who have real attention to detail, a good sense of accountability and responsibility to carry out the guidance and procedures to keep the environment clean and operational.”

And what constitutes effective operation of the cleanrooms?

“My role and the role of my team as technical staff is to make sure the equipment is operational to the best of its ability for researchers to carry out their work,” says Fran.

“We keep consumables stocked up, fix equipment when it breaks. For my experimental officers, one of the key roles is to drive the equipment and processes to the edge, to get the most out of them. Then it is up to our researchers and industrial partners what you do with that equipment and what device you fabricate with it or what prototypes you might make.”

This is a key point. For all its shiny kit, the NGI is only as good as the people bringing their innovations to the table. And the relationship between the institute and its external partners is bound by rules around the NGI’s funding model, which we’ll explore more fully below. But first, some personal detail.

The road to Manchester

On the roof of the NGI is a sun terrace that provides an altogether different atmosphere from the controlled environment below. And divested of PPE, Fran suddenly appears less a buttoned-up lab manager and, with beard and flowing locks, more akin to a kindly restaurateur or motorbike enthusiast. We meet (for a ‘second’ time) to discuss his background in materials science.

“I’m originally from Benidorm but I did my degree in physics at Portsmouth and found a job in photonics, working for Pirelli at an optical fibre factory,” Fran recalls. “Lots of people only think of Pirelli as tyre-makers, but they also made electrical cables and fibre-optics and this was one of the biggest operations in the world at the time, making 6,000km of optical fibres per day.

“I was a development engineer, finding new techniques to increase the deposition rate of the manufacture of optical fibre. I loved the job – it gave me flexibility and every day you could see progress.”

From there, Fran was persuaded by Pirelli head office to work in their new R&D facility in Milan, including a year’s placement at MIT, where he first encountered the kinds of big cleanroom complex that are now his area of expertise.

“I went to back to Milan after MIT,” he says. “But it was clear the business unit wasn’t going to last long, so I found a job at the Technical University of Valencia – that was in 2007 – and I was soon promoted to Cleanrooms Manager, so that’s been my job title for 14 years now, seven in Valencia and seven here in Manchester.”

So why come back to the UK?

“I was actively looking for a new challenge and, as an anglophile, also looking to return to the UK. My twin daughters were only two at the time and I wanted to give them a bilingual and bicultural education.”

Fran has overseen initial and ongoing development of the NGI Cleanrooms since before the institution’s opening in 2015 and now, as graphene and 2D materials reach an important commercial tipping point, especially around sustainable applications, there is increasing industrial interest in engaging with the facility.

Rules of engagement

We mentioned the funding arrangements for the NGI and, in brief, they are as follows (please pay attention at the back of the class). The NGI is funded partly by the UK government and partly by the European Regional Development Fund (ERDF). So, due to state aid rules, the institute may engage with industrial partners but cannot charge for what’s known as ‘contracted research’.

This means a company partnering with the NGI is not allowed to deliver a product direct to market through the institute. But it may pay for access to, for example, specialist high-capital-expenditure equipment to advance its research, or it may sponsor a PhD or post-doctoral researcher to work on its behalf in the building.

Essentially, the NGI is a research institute and collaborative space for knowledge exchange with the nine departments that make up The University of Manchester’s Faculty of Science and Engineering. These departments themselves can, and do, have multiple industrial partnerships – from local SMEs to multinational corporations – and may charge for academic input and expertise, plus equipment time, prototyping etc.

Where the NGI comes into its own for industry is as a nexus for these services around graphene and other 2D materials, operating at cost, with highly specialised equipment and knowhow to take fundamental scientific concepts to the next technological readiness level (TRL).

This knowledge can be taken back to the partner company or institution for prototyping, or may stay on campus and be taken for further development to the Graphene Engineering Innovation Centre (GEIC) – the sister institute of the NGI, which has a different funding arrangement and is specifically set up for prototyping and product development.

So what does all this mean in practice for practitioners who might make use of the NGI’s cleanrooms?

Cleanrooms case study 1: Bangor University

Dr Maziar Nezhad is a Reader in Nanophotonics and the Director of Research in the School of Computer Science and Electronic Engineering at Bangor University. His work in the NGI began in 2017.

“I had funding from a Welsh Government grant (under the Sêr Cymru National Engineering Network scheme) and I needed access to advanced semiconductor device fabrication tools. Bangor has its own cleanroom but some of the necessary key tools were missing from our equipment line-up,” says Maziar.

“Fortunately the NGI was within a reasonable distance from Bangor and they had both the required equipment and the necessary access and training protocols in place to allow an external user to use the facility.

“My Sêr Cymru grant eventually led to a successful EPSRC bid, in the form of an Innovation Fellowship (ongoing) and that has provided me with the additional research time and resources to continue my work at NGI and expand it into different directions.

“My current research covers nanophotonics and MEMS (Micro-Electro-Mechanical Systems), with a focus on device design and development and so access to the NGI and the fantastic line-up of nanofabrication tools there has been crucial to advancing my work and a great example of knowledge exchange between institutions.”

Cleanrooms case study 2: National Physical Laboratory (NPL)

A group of PhD students from the ‘Quantum materials and sensors (QMS)’ group at the National Physical Laboratory (NPL) were able to work at the NGI following the Henry Royce Institute Academia Scheme.

Dr Eli Castanon and Tom Vincent, started work at the NGI in 2018, using the cleanroom to produce a range of different 2D materials heterostructures from encapsulated graphene to complex encapsulated InSe Hall bars. In 2019, Alex Browning also employed this scheme to produce several samples of transferred CVD graphene.

Dr Eli Castanon

“Our current research focuses on the nanoscale characterisation of optical and thermal properties of 2D materials using Scanning Probe Microscopy (SPM) methods. We had a range of ideas for possible experiments.

“As NPL specialises on advanced measurement techniques, we don’t own the fabrication facilities needed to produce the devices of interest. So we contacted the Henry Royce Institute, and applied to access the NGI Cleanrooms.

“The process was very smooth. Our applications were reviewed by a panel of experts and a PI was assigned to us based on the expertise that we required.  At the NGI, we were welcomed by our host Professor Roman Gorbachev and his group. We received a complete training on all the nanofabrication techniques, and we had constant support from the people in the group during our stay.

“The heterostructures produced have helped us unravel interesting thermoelectric properties of 2D materials. The effects observed conform a huge leap forward in the realisation of thermal management at the nanoscale. After these studies, we maintained the collaboration with the NGI, leading to further experiments, and the preparation of high-impact-factor publications together.”

Tom Vincent

“The combination of atomic thinness and superb mechanical strength means that 2D materials can withstand very large strains without damage. This creates an opportunity to use strain to tune the materials’ properties for specific applications, such as wearable sensors or nanoscale optoelectronic devices.

“At NPL, I research how nanoscale strains affect how graphene interacts with infrared light. Understanding this could provide pathways towards miniaturisation of optical-to-electronic interconnects, or even on-chip optical computing. Bubbles are a great way to induce complicated strain patterns to 2D materials, making them an exciting platform to study strain-related effects. When I needed tailor-made encapsulated graphene devices with bubbles, the NGI was the obvious place to turn.

“I spent several weeks in the NGI Cleanrooms, learning to exfoliate and transfer 2D materials under the expert supervision of University staff and students. Their world-leading fabrication expertise was well complemented by their research excellence, which made the process of explaining my experimental needs effortless.

“They didn’t just help me to create the devices I planned, but also gave me valuable feedback on how I could change my designs to make my experiment go more smoothly. With their guidance, I was able to turn my zero cleanroom experience into working devices for my experiments.”

Alex Browning

“My research aims to investigate the physics of single-photon emission from novel 2D material sources with the aim of advancing current technological capabilities. At NPL, I work within the Quantum Materials and Sensors (QMS) group, which has an advanced suite of multiple scanning probe microscopes (SPM) for nanoscale electrical, optical and magnetic characterisation, and the Quantum Information Processing (QIP) group, where we characterise the quantum optical properties of single-photon emitters.

“At NGI, I aimed to fabricate a single-photon source of a scalable 2D material (CVD produced) and deterministically place single-photon emitters that work at room temperature. The samples required were complex, multi-layered and involved several different fabrication methods.

“I was allocated an experienced experimental officer from the NGI to perform the fabrication with and over the course of just one week, we produced many samples for further experiments and characterisation at NPL in the QMS and QIP groups.”

Find out more about the capabilities and kit in the NGI Cleanrooms on the NGI website.

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