The future of semiconductor chips: is Nanoimprint Lithography the next big thing?

They’ve grown smaller and more powerful for decades, but will computer chips soon reach their limit? Or is nanoimprint lithography the answer to their future?

Our world becomes more and more computationally intensive by the day. Smartphones, laptops, home electronics, cars – it’s hard to think of a part of our day-to-day that doesn’t have semiconductor chips in it.

They’re behind most aspects of our lives and they come out cyclically in even more advanced versions. But from a production point of view, keeping costs down while reducing their size and increasing their power is no easy task.

Based on the theory that follows and predicts their evolution – the so-called Moore’s Law – advancements in speed and capability should happen approximately every two years and are meant to only minimally affect their price.

But as that becomes increasingly challenging, how can this delicate balance be guaranteed in years to come?

We think that Nanoimprint Lithography (NIL) will be key in achieving it. Here’s why.

What exactly does Nanoimprint Lithography mean?

“Nanoimprint Lithography is what’s commonly known as an ‘advanced lithography technique’,” explains Chris Howells, European Operations Director for Canon’s Semiconductor Equipment Division. “And our own version of it draws from our expertise in inkjet technology.”

In fact, Canon has been in the business of supporting semiconductor manufacturers all over the world for close to fifty years, supplying them with state-of-the-art equipment for semiconductor lithography. This is the process used to print those small, highly defined patterns that you see on computer chips. It involves applying light or radiation to transfer a pattern onto a wafer coated with a viscous liquid called photoresist.

In this context, NIL feels like the natural next step – being able to combine Canon’s decades of extremely specialist knowledge of print with photonics (the science of light).

But what does it do? And how is it different from any other type of lithography?

Shrinking the future

The process of producing nanoimprint lithography is quite different than traditional semiconductor lithography, partially due to its complex design.

Firstly, instead of printing a pattern onto a wafer that is completely coated with photoresist, NIL releases droplets of the liquid only where it is required. Using the same technology that can be found in Canon inkjet printers, each drop can be measured, controlled, and dispensed with precision.

Then, a specially manufactured stamp called a ‘mask’ presses the desired pattern into the liquid. This may sound straightforward but remember we’re talking about a minuscule scale requiring absolute precision. Something as simple as air being trapped between the mask and the silicon wafer would completely derail the process, so the developers and designers of the machines had an exceptional challenge to avoid any external elements.

Inevitably, more than one mask will be required over the lifetime of a NIL system. These too are created using a machine that is also manufactured by Canon. “Essentially, the two machines together create an in-house sourced process for nanoimprint technology,” explains Chris.

The last part of the process is when the mask is removed, leaving tiny structures that are then cured with UV light. These intricate and quite beautiful geometric patterns are invisible to the naked eye, their size being only a few ‘nanometres’, hence the name.

To put that into context, a nanometre is one billionth of a metre and a human hair will measure around 100,000 nanometres in diameter. “The smaller the ‘feature size’ [the tiny physical structures] on the silicon chip, the faster the device it’s used in will operate,” explains Chris.

“So, phones become faster; your PC is quicker. The more advanced your lithography equipment is with printing smaller feature sizes on the chips, the better the performance of that chip will be.”

More precise, cost-effective and better for the environment

There’s no doubt that a process so big and complex will require significant investment on the part of chip manufacturers, but we think this is a wise move in the long term. As a testament to our commitment, we’re currently planning to build a new semiconductor equipment plant in Japan. This will double our current capacity and allow us to produce even more lithography equipment than ever.

“The overall cost of ownership shows that this is a technology worth investing in,” explains Chris. “That’s in terms of running costs, throughput, as well as longevity.”

Cost, of course, comes in many shapes and forms. So, from a machine perspective, it’s understood that NIL as a process will offer excellent value for money to manufacturers – not just in the initial investment, but by virtue of the way the technology operates.

For example, when you compare it to the closest alternative (‘Extreme Ultraviolet Lithography’ or EUV) or even traditional semiconductor lithography, both power consumption and waste are substantially lower. The precision nature of the process means that there is little in the way of excess material to be discarded and this too markedly reduces the use of chemicals. Both of which can have huge environmental impacts on top of costs too.

Combined, we are looking at the kind of progress that will not only secure the legacy of Moore’s Law – in terms of processor speed and power – but also adds a new, crucial sustainable aspect to the manufacture of semiconductor chips.

Meet the team behind the development of Canon’s Nanoimprint Lithography System.