At a fundamental level, the specifications for a specific thin-film coating will drive the overall requirements for a vacuum deposition system. Wise choices early in the concept phase will reduce the overall cost of a coating system without sacrificing the throughput or film quality.
Here are four suggestions to help you end up with a deposition system that meets your needs at a reasonable price:
1. Select the proper substrate size for your tool.
The maximum dimensions of the substrates are usually the largest cost driver for a deposition system. Larger substrates sizes require larger vacuum chambers along with larger pumps and gate valves. Larger substrates also will require larger deposition sources with bigger power supplies or more powerful lasers if doing PLD. To minimize the system cost, choose the smallest substrate size you will routinely use. Don’t oversize a system for the odd chance you will need to run a larger substrate several years down the road.
2. Consider all aspects of the deposition process.
Complex coatings, such as those requiring co-deposition utilizing two or more materials, may require multiple monitoring devices within the chamber. If toxic or highly reactive species are required, considerable planning must occur during the design phase to address issues such as safe ventilation and serviceability. All these things can add significant cost to a system, especially if not planned for in advance. Up-front planning is imperative to evaluate all the associated costs of a system.
3. Plan and prepare your facilities and lab.
We can't say this enough: Plan all aspects of your system installation well in advance, and be ready when the system arrives. Your plan needs to start at the loading dock (Do you have a loading dock?) and end with the first production run. For detailed advice, read our previous post, Why Early Facility Planning Pays Off.
4. Define your required throughput and minimize risk.
The requirements for R&D vs. production systems are significant. In both cases, you want to be thrifty but not cheap. For R&D deposition systems, throughput may not be a serious concern; however, the addition of a loadlock to an R&D tool can easily double the throughput for an incremental cost—typically 10 to 15%. For production deposition systems, it is best to design your deposition tool capabilities to maximize the production rate while still being ergonomically functional. This may lead to some expensive up-front costs for features such as fast pump-down times, large loadlocks, or larger deposition sources and power supplies. However, "simple" tasks like target changes and cleaning internal parts become more important to consider for production-oriented tools. In some cases, multiple tools are a better choice to meet high volume throughput requirements. Multiple production tools also minimize the risk of having an entire production line go down while a key part is replaced.
Following these four tips will ensure that your deposition system is well-aligned with your coating needs. Planning and taking action at the beginning of the concept and purchasing phase will save you considerable time and cost in the end. You will end up with a coating system that meets your needs without sacrificing performance or wasting funds.
Gain better understanding of how to balance cost and capabilities during thin film deposition system design in our latest download, Cost-Drivers for Thin Film Deposition Tools.