How fast is fast?

Redefining fast ALD with the new Beneq C-Series ALD tools

Last month, we launched the first two products of our new cluster-compatible ALD product family, the Beneq C-Series. The new automated cluster solutions have been designed for industrial ALD applications where high capacity is needed. The number of wafers they can process is massive compared to traditional ALD equipment.

Those who work with wafer-based production immediately get it: 20 000 wafers per month is a lot. That is why we talked about fast wafer processing and an ALD throughput revolution in More than Moore markets when we launched the new products in Semicon Europa.

But at the event, we soon realized that there are many people in other industries and research units of industrial corporations who are interested in ALD and deposition speeds, but do not count production speed in wafers per month. They asked us a lot of questions about speed and how we measure fast ALD.

The purpose of this blog post is to go dig deeper in deposition rates and explain what fast ALD and high-throughput ALD equipment mean.

Fast ALD with Beneq C2

When we talk about throughput, we must consider many different factors of the production setup. There is of course the deposition rate of the actual ALD process in the chamber (in nm/min), but you should also consider the capacity of the chamber (the batch size) and the automation solutions around the ALD equipment. Things like heating the wafers to the process temperature and the cooling time after the processing matter a lot when we count the total throughput.

For a micrometer-thick coating (in our world that is really thick…), it’s all about optimizing the cycle time and batch size. But when the target is a 10-nanometer-thin film on a large number of wafers, the wafer handling, heating, cooling, etc. takes much more time than the actual ALD deposition. To increase throughput, one then must optimize all the auxiliary equipment around the ALD tool.

Let’s compare for example the effect of pre-heating of wafers in a traditional ALD tool that uses batch heating in the reaction chamber to the advanced pre-heating system that we use on the Beneq C2 ALD equipment:

  • A typical case of a temperature sensitive ALD process, such as TiO2,, in batch heating in the ALD tool itself: 25 wafers, loading at room temperature, heated in the ALD reaction chamber – pre-heating time 120 min to reach uniform temperature.
  • Single wafer heating of Beneq C2: same 25 wafers, pre-heated wafer-by-wafer, 10 s/wafer, total pre-heating time 25 times 10 s = 250 s = 4 minutes and 10 seconds.

This combined with the speed of the actual ALD process results in a unique combination of high capacity batch processing and standard cassette-to-cassette automation. Beneq C2 can process up to 20 000 semiconductor wafers per month (10 nm of Al2O3 ALD coating on 200 mm wafers).

That’s how fast Beneq C2 is.

How fast is Beneq C3R?

The capacity calculations also depend a lot of the type and the thickness of the coating to be applied. In many wafer-based industrial ALD applications, the ALD coating is quite thin, often just some of tens of nanometers. In those cases, the throughput depends more about the automation speed and the heating and cooling solutions as described above.

The situation is different when the coating needs to be thicker. This is the case for example with many optical ALD coatings, which can be up to a micrometer thick complex nanolaminates. For this kind of ALD solutions, the deposition speed matters more. That’s when spatial ALD shines.

The Beneq C3R is a great example of fast spatial ALD equipment. It is also cluster-compatible and can be automated, but the rotary chamber where the substrates to be coated move between a precursor zone and a plasma zone, increases the deposition speed to a whole new level.

Because of the plasma enhanced rotary ALD process, the Beneq C3R is ideal for thick ALD films on wafers in industrial applications, such as optical coatings and insulators for high power semiconductors.

The rotation speed of Beneq C3R can be up to 200 revolutions per minute, which results in over a micrometer of ALD per hour for typical oxides, such as Al2O3, TiO2 and SiO2. And what’s more: this is done for a batch of wafers simultaneously.

That’s how fast Beneq C3R is.

Beneq’s single-wafer tools are fast too

When considering ALD tools for wafer-based research and development, process flexibility and the possibility to deposit a wide variety of materials on various wafer sizes is often more important than process speed. But sometimes deposition speed matters in research too.

The Beneq TFS 200 research equipment and the single-wafer version of Beneq C2 are the tools for wafer ALD research and production. They are fast too.

An example again: SiO2 can be deposited on a Beneq single-wafer system at deposition rates of over 10 nm per minute (if you want to know more about the measurements, get in touch, we will be happy to provide you with references and test results).

The throughput revolution in wafer-ALD

Increasing ALD capacity and moving ALD from research laboratories to industrial production has been Beneq’s focus for a long time. Our customers are now reaping the benefits. No matter what your application, the story is simple: For ultra-fast ALD, the right address is Beneq.

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