August 2017 newsletter

Ion Times

Milling About

Here at Plasma Process Group we have recently made the investment in a second CNC Mill for grid manufacturing! We expect to have the new mill in-house by mid September, and reach full production capabilities in October. This should help bring down the lead times many of our customers have been faced with over the last few months, and in the future to fill larger orders more quickly.

A Ghost in the System

Your deposition system has been trundling along, making product and money for years now, perhaps even decades, when suddenly something goes wrong. Maybe you know exactly what the problem is, perhaps you don’t and the problem is just a ghost (or shall we call it a specter?) in the system. Either way, Plasma Process Group has the solution. We can provide replacement parts for many of the components of your Ion Tech style equipment, from ion sources and grids to neutralizers, power supplies, and even beaded leads and heater bulbs! Give us a call, and we can start getting your process back from the dead zone!

How to Make Ions (Part II)

So you’ve decided to get a new (or upgrade your existing) ion source. You know you want ions, but you don’t know how best to make them – will a DC ion source work? Do I need an RF ion source? Is having more ions always better? Can the ion source be 3cm from my substrates? Can the ion source be 3m from my substrates? Will convergent grids increase my deposition rates? There can be a bewildering array of questions, possibilities, and options, and that is why Plasma Process Group is here to help! We will take whatever information you can provide about your chamber, expected process, and specifications, and help you put together the ion source package that works best for you!

16cm RF Source
16cm RF Ion Source
3cm DC Source
3cm DC Ion Source

Once the ions leave the ion source, it makes no difference whether they were created using a DC or RF ion source. They will have the same downstream properties, and the same effect on your targets and substrates. It is what happens inside the ion source that makes a difference. A DC source is simple, robust, and inexpensive, but the high-current filament that creates the plasma and neutralizing electrons is quite vulnerable to reactive gases. DC ion sources are available in 3cm, 8cm, and 13cm sizes. RF sources are far more versatile, allowing the use of reactive gas or combination of gases in the ion source, and have very low maintenance requirements, but are more complex and more expensive. RF ion sources are available in 6cm, 12cm, and 16cm round, and 6cm x 30cm rectangular sizes. The size of the ion source largely determines the maximum beam current that can be extracted.

Both DC and RF ion sources can be provided in any of three different mounting configurations. Flange Mount offers the ion source fixed directly to a flange, with the back of the ion source typically being the flange itself. This uses the minimum amount of space inside the vacuum chamber, but offers no flexibility of movement or positioning – the ion source points straight out from the flange. Extension Mounted ion sources are also fixed to a flange, but are extended out from the flange itself using several posts. This allows the distance between the ion source and its target to be set to whatever value is required in the chamber, but still does not allow any angular adjustment. Internal Mount takes the ion source off the flange entirely, and allows it to be positioned at any angle desired inside the vacuum chamber. This configuration also allows the largest variety of flange options.

Grids for your ion source are available in four general categories. First, convergent grids narrow the ion beam to create a higher-density plasma that can improve etch and deposition rates at the sacrifice of uniformity. In a deposition process, convergent grids will tend to punch through the center of the target material rapidly, giving a very low utilization fraction. Second, divergent grids spread the ion beam and create a more uniform density plasma that improves beam coverage and process uniformity at the expense of etch or deposition rates. These grids are usually the optimum choice for Ion Assist applications, as they provide the largest and most uniform coverage area. Third, multi-focal point grids use varying convergent and divergent regions on the grid to create a (relatively) uniform beam over an optimized diameter. Typically these grids are used for deposition operations to provide good deposition rates while still using a much larger fraction of the target material. Finally, flat grids (usually graphite) provide a collimated ion beam. Flat grids have highly predictable ion beam shapes, but offer few other advantages or disadvantages. Be sure to check out our grid selection guide.

Collector include unstable RFN emission, inability to reach high emission levels, and over time an increase in required gas flow to the RFN due to increased erosion of the ceramic discharge chamber. All of these can cause complete process failure when the ion source in turn becomes unstable and goes out. A new Collector can provide as much as 3000 hours of performance before replacement.

At Plasma Process Group, we understand the importance of a functional RFN. We also understand how to disassemble, clean, and reassemble an RFN to reach the highest number of hours of performance between refurbishments. Send us your failing RFNs, and we’ll send them back cleaned, repaired, and ready-to-go, helping you keep system downtime as low as possible and results as consistent and reliable as your RFN!

The remainder of an ion source package is determined by the choice of source size, type, and mounting. We are hear to help you with these selections and provide a quote for your desired setup.

13cm DC Source
13cm DC Ion Source

Plasma Process Group – Simple Ion Beam Solutions