Thursday, June 20, 2013

Low temp or high temp in ALD, we've got you covered

We've been learning a lot about what's really needed in ALD, and we've found that aside from using QCMs for in-situ, real-time monitoring for precursor development, wafer production, and exhaust maintenance, there's a need for both a temperature controlled AND a non-temperature controlled sensor. It really depends on the user's needs, and it's heavily dependent on their temperature limits.

For example, most users can put a non-temperature-controlled, Phoenix sensor head and Eon-LT controller (or monitor) into their basic ALD system, and it will do all they need in wafer production. The sensor housing is operational to 500C without a need for a separate heating/cooling control, and the electronics will provide high resolution (higher than competitor) at an extremely high rate with exceptional accuracy. The key here will be the crystal cut and coating of the resonator (many cannot have gold or copper anywhere within a chamber, for example). Cut matters, as it determines how high the temperature can go before a crystal phase change begins. We recommend our patented RC crystal for up to 300C (most applications), HT for between 300-400C, and SQ for 400C+.

If, however, the user needs to control temperature, raising and lowering (for handling) the sensor up to 700C, then the Cadillac of systems is necessary--Tempe and Eon.  Many users need this premium system for precursor development and exhaust maintenance, both of which can exceed the 500C temperature limit and require careful control of substrate temperature. Eventually, the majority of systems will get to this point, but for now, most research institutions and commercial operations only need a "Basic" system as they learn how to use QCM in a variety of ways for low-cost, real-time, in-situ measurement.

So, how are they different?

Well, there are a lot of similarities in features, as we built both systems to be robust, but the key difference is the ability-inability to control temperature. Tempe/Eon CAN; Phoenix/Eon-LT CANNOT. You might think it's not such a big deal to control the temp or get to higher temperatures, but not only are parts a lot more expensive, the science it took to create a system to withstand such high temperatures (just in springs and integrated heater, for example) took 3 years and millions of dollars to achieve. It's complicated, trust me. And let's not start about what it takes to write the software to correct for frequency vs. temperature! Ach, the algorithms!

So, if you need to reach temperatures above 500C or if you need to control temperature for other reasons, we recommend the Tempe/Eon system with software optimized for ALD. But, if your process is relatively low temperature, and you have no plans to exceed 500C, plus you don't need to control sensor temperature, a basic Phoenix/Eon-LT is all you need. You may even need 3-5 for optimal, large-wafer uniformity. The beauty of the Phoenix/Eon-LT system is that it's only about 1/4 the cost of the full-featured Tempe/Eon system.

You realize that makes it the same cost as those other guys, right? With support...and without the politics.

You know you want one. Or three.

+1 480-634-1449 today


  1. Hello Friend,
    I am using RC cut crystal with gold plating from Colnatec. I wanted to as if you know about the active area and how I can calculate the mass uptake per cycle. Also Do you think I need to write temperature Algorithm for my application (i.e from 150 deg C upto 400 deg C)

    thanks in advance,

  2. Hello, Varun. Can you contact us directly at or 480-634-1449, so we may answer your question more specifically? We don't have your email address from this comment post, and we have a couple of questions. Thanks!


Thank you for your comments. Please note that spam comments will be deleted before publication.