In February, I got the opportunity to find out. Taking my first company trip as part of NuNano, I headed up to lovely Edinburgh to meet our engineers and to see how our AFM probes are manufactured in the cleanroom of the Scottish Microelectronics Centre.
It has been around five years since I last stepped foot in a cleanroom, when I conducted some device fabrication as part of my PhD. Like any environment, when you work in it every day, it becomes pretty normalised, but for the majority of people, including users of AFM, a cleanroom is an intriguing and unknown place they’ve never experienced.
For those people who don’t know, a cleanroom is just that – a clean room, with no dust, no tiny bits of fabric, or anything that can get on or in the tools and materials worked on within it. This is important for delicate processes such as the fabrication of AFM probes. Contamination of this type would adversely affect both the manufacturing process and the quality of the final product.
To ensure the room is clean, the air is constantly recirculated through filtering systems. Air is drawn from outside, filtered, and blown into the room in such a way that, if someone opens the door, the air always blows from inside the room out.
The dirtiest thing going in and out are in fact the cleanroom users! Consequently, this means suiting up, from head to toe, in a garment a bit like a full coverage painting suit. Piotr, one of our process engineers, had to remind me of the suiting up steps as there is a strict protocol to follow when dressing yourself to ensure that you minimise any outside contaminants entering the cleanroom. I must admit it took me much longer to get myself ready compared to the minute it took him. Let’s just say I made sure I had everything I needed before entering the cleanroom to avoid having to suit up again.
As we walked through the cleanroom, I was surprised to find that I wasn’t easily able to distinguish between different people. Everyone was wearing the same suit with a white mask covering their nose and mouth. Save for our managing director (MD), James (easily recognisable because of his tall stature!), I was struggling to pick out our other engineers, Nathan and Richard, who I had just been introduced to in the office. Piotr told me that by now he picks people out by their way they walk and move.
Watching our engineers work, I realised that the process of fabricating our AFM probes is very methodical and requires care and patience. Special care must be taken especially during the wet chemical etching processes, which require extra health and safety precautions. Our engineers must wear a heavy-duty visor and chemically resistant gown, along with thick gloves when working with chemicals.
The manufacturing process also involves operating both manual and automated equipment. Although the automated machinery can speed up the manufacturing process, it can’t always be trusted. Our engineers still mourn the loss of a whole wafer of probes by one of the automated instruments.
The video above gives some insight into the level of noise within the cleanroom. The hum of the instruments along with the filtering system was quite overwhelming at first but I soon got used to it. Emerging from the humidity-controlled environment of the cleanroom after two hours, I felt quite dehydrated. It made me realise just how important it is for users to take regular breaks outside the cleanroom.
It was great to meet our engineering team face to face for the first time and to really get a sense of what it is like for them day-to-day, manufacturing our AFM probes in the cleanroom. A huge thank you to Piotr for showing me around.
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