Particle ALD: From R&D to Commercial Scale

Dr. Markus Groner – Forge Nano


How do you take a promising lab-scale particle ALD process or application and take it to industrial scale? We’ll discuss everything from chemistry development all the way to high-throughput spatial ALD for particles. Forge Nano has years of experience and a diverse set of PALD tools for processing anything from grams to tons of powder.

0:00:01   Good morning. My name is Markus Groaner. I'm a senior scientist here at R. And D. Department at
0:00:12   Fortune nano. And I'm here to talk to you about how to scale up particle A. L. D. And as you may
0:00:19   have noticed there's been a lot of exciting news in the colorado L the community where we now have
0:00:28   three local L. D. Companies under one roof forge nano on the outskirts of Denver and we're all very
0:00:37   excited to be able to working with each other and joining forces and resources to do um all kinds of
0:00:46   L. D. And provide all kinds of equipment including semiconductor equipment. Now
0:00:58   today I'm gonna be talking about the process we go through when we want to take an exciting new lb
0:01:08   process or exciting new particle LD application um to code powder and make better materials with it.
0:01:18   Which then it can be used to make exciting new improved products including batteries and catalysts
0:01:25   and many other applications that you've been hearing about all morning. So I'm gonna talk really
0:01:37   more about the process and the methods and the resources and the the tricks we have to scale up
0:01:45   particle A. L. D. And it's basically a force that process um Where we first look into the standard L.
0:01:52   D. Process development to validate a chemistry. Um Then we scale that too inert powders as the
0:02:02   second step next is actually doing the particle alia on the customer's powder substrate typically on
0:02:12   the order of grams to kilograms before we then go on to commercial production. Typically on the tons
0:02:20   kind of scale. So of course this is the ideal process that we like to follow but that's not always
0:02:29   the case. Um People always want shortcuts or they might be a reason to skip a step in some cases. So
0:02:42   to go from a promising new A. P. L. The application that's been reported in the literature for
0:02:47   example to commercial production. And this is where fortunate comes in. And of course we do the
0:02:54   standard L. D. Process development an investigation into precursors and and all those kinds of
0:03:01   things that everybody is probably familiar with here. But more importantly we are very focused on on
0:03:09   how to apply these new processes to the customers substrates and make it work for their application.
0:03:19   And that's where we're substrate compatible limitations may come into play. We have to think about
0:03:26   cost, timeline and more important the customer's own testing. So when we scale L. D. Um to two large
0:03:41   batches of powder we of course have to consider powder behavior. Um precursor amounts that we use
0:03:50   are much much higher orders of magnitude higher than for away for LD. So we have to consider that.
0:03:56   And and there's multiple tools we can pick from two scale the process to particles. Of course we
0:04:04   have the standard types of analytical techniques that you might think of for a L. D. Including some
0:04:09   in situ monitoring. Um lots of particle characterization and of course we care a lot about
0:04:16   reproducibility since that's important for for industrial scaling. Um At the very large scale the
0:04:24   batch versus continuous LD processing options have to be considered. And I talked about that a
0:04:33   little bit more later. And of course powder handling of large volumes of powder become very
0:04:40   important and even more important is actually to consider what kinds of processes the industry is
0:04:51   used to working with are willing to accept to introduce them to their into their chain so that comes
0:04:59   into play as well.
0:05:03   So going back to the plb scaling process, four step process that I want to talk about. Uh The first
0:05:11   step is just doing the standard L. D. Development on silicon wafers on Q. C. M. Or we can look at
0:05:20   the mass cane uh while we run TME water for example
0:05:29   and a standard um L. D. Tool where we look at temperature and growth rates and the South claiming in
0:05:38   nature. And also we have, we often want to consider multiple different precursors for a certain
0:05:45   process to give us options down the road. A. L. D. On silicon wafers can be done very fast in the
0:05:55   new tools that we are now now selling uh in collaboration with Sun do um These uh ultrafast wafer
0:06:05   tools are on the order of one cycle per second. And then we'll be talking about this new L. D. To
0:06:13   the X. Presentation tomorrow in the Tuesday am session.
0:06:25   And of course we have standard analytical techniques to look at thin films on waivers. Now the main
0:06:34   purpose of this is not to uh necessarily publish a paper or or uh explore the chemistry in detail
0:06:44   but rather to kind of get a down selection of the process conditions. Find that we might then want
0:06:51   to use for the subsequent particle L. D. Scale up mm. So step two is transferring this alien
0:07:04   knowledge to particles and we typically use inert powder substrates um in a small fluid ized bed
0:07:13   tool. That's a nice tool for this kind of work it allows us to do in situ R. G. A monitoring of the
0:07:24   gases that come out of the exhaust the top of the fluid bed tool and do all kinds of chemistry
0:07:32   studies and and make sure that the L. D. Coding is coding going down as expected precursor delivery
0:07:41   becomes a big deal once we scale to particles because we can have orders of magnitude more surface
0:07:48   area than for typical object coding type LD tools. So, vapor pressure and long term stability to
0:07:59   hide that high temperature is important for the for the precursors that we're considering. And of
0:08:04   course the for the Q. C. The primary tool here is elemental analysis using ICMP. We can we can also
0:08:14   compare the calculated amount of deposition deposited materials to the actual and we also look at
0:08:26   surface area moisture and sometimes other things like powder flow or or imaging the particles and so
0:08:34   on. So really the main question we're trying to answer here is does the L. D. Process translate well
0:08:43   two doing LDL particles? Um Certain non ale ideal LD behavior maybe Okay if you're running wafers
0:08:55   but sometimes these issues really show up when you try to do them on particles and sometimes vice
0:09:02   versa as well.
0:09:06   For example uh to L. D. Tends to work quite nicely on waivers would take a long water but we found
0:09:15   it to be very amenable to particle processing just as an example.
0:09:25   Mhm. So we'll talk here a little bit more about fluid ization of particle beds. Um Since since we're
0:09:34   primarily using the fluid bed tool at this stage of the process, it's it's really nice way of
0:09:41   processing particles. Um It's kind of a commercial processing tool that we applied a particle A. L.
0:09:49   D. And run at low pressures and it really has nice mixing um Solid gas mixing, great heat transfer
0:09:57   so it's easy to heat the powder uniformly. And we can characterize the politicisation behavior of
0:10:05   the powder by by graphing the pressure drop versus the gas flow to get our fluid Ization curve has
0:10:14   shown on the right here and basically as soon as you hit the minimum fluid ization gas flow velocity,
0:10:22   um the powder starts behaving like a liquid the bad expands and if you add more gas beyond that than
0:10:32   you get um bubbling fluid Ization, which is probably what you're seeing here on the right were
0:10:39   operating above the minimum fluid ization and that's usually ok. And globalization is a whole
0:10:46   science and also somewhat of an art, I would say, with lots of tricks that we're going to talk a
0:10:52   little bit about later. And of course, uh not all substrates behave quite like this carbon over here
0:11:01   does.
0:11:06   So next, I'm gonna talk about the wonderful things we can do and we combine a mass spec with the
0:11:12   fluid bed reactor L'D tool. So we're looking at the exhaust gases that are coming out of the top of
0:11:20   the fluid eyes bed. And we can tell all kinds of things about the chemistry and the processing going
0:11:28   on in that fluid ice bed uh starting with substrate dying and outgassing. That happens when you
0:11:35   first start heating up and pumping down the the particles.
0:11:44   Then of course there's the L. D. Mechanisms that you can figure out by looking at the various
0:11:51   species that
0:11:54   are generated when you do the L. D. Um And then even more importantly perhaps is that we can detect
0:12:03   when an elder reaction has saturated. That works especially well for for fast ale reactions. So on
0:12:11   the right here you can see that when you start tomatoes, you've first, all you see is uh the methane
0:12:21   signal in red. And then after seconds minutes hours that methane signal starts starts to decrease as
0:12:29   the surface is becoming saturated. And you see a rapid rise in the T. M. A. Signal and that tells
0:12:39   you that the reaction is saturated and then you can move on to the purge and then the water dose
0:12:45   which does pretty much exactly the same thing at first. All you see is the methane product. And then
0:12:51   when all of the surfaces in the bed have been coded
0:12:56   you get water breakthrough. And the nice thing about all this is that you can even automate the
0:13:02   process
0:13:05   with with with software and and run hundreds of cycles of a process like this. And and more
0:13:13   importantly perhaps for a scale of is that we have very high precursor usage. Um we can easily
0:13:20   achieve greater than 90 precursor utilization and a lot of these processes with the mass spec. And
0:13:30   that's very important when you're going through tens or hundreds or even kilos of a certain
0:13:35   precursor doing a run.
0:13:46   Okay so once we get the L. D. Process working well on a nerd substrate, we go to the third steps
0:13:53   which is dealing with the particles that the customer has provided for their application. And that's
0:13:59   where we run into challenges with powder handling and fluid ization sometimes um including
0:14:06   agglomeration and loot creation and all kinds of issues, things that can happen. And for example on
0:14:13   the right here we have what looks almost like a paste,
0:14:19   fortunately when we started processing this material in the fluid bed, it actually started um fluid
0:14:27   izing quite nicely. Um So sometimes all it takes is drying of the substrate.
0:14:36   Another issue that arises that is that the L. D. Precursors sometimes can interact um with the bulk
0:14:46   of the powder rather than just with the surface. And that's that's often a challenging situation
0:14:52   that you can perhaps get around by using different precursors or doing different things during the
0:14:59   new creation phase of the process. And of course, some powders have very high porosity, temperature
0:15:07   limitations or they have ah inert loading requirements or certain safety issues to deal with as well.
0:15:17   We also have different types of particle ailed coding tools at the small scale. We use not only the
0:15:24   fluid ice, but also the rotating drum. Mhm. Both of these can be done at grams to kilograms types of
0:15:34   scales. And just to give you a brief introduction of rotary mixers, blenders, whatever you want to
0:15:42   call them reactors. The powder is basically cascading in a rotating drum and this allows you to do
0:15:52   static dozing. You don't have to constantly uh fluid eyes, the powder with with gas flow. And it's
0:15:59   also very useful if you want to do high surface, very high surface area porous powders or perhaps
0:16:05   slow Ellie processes. And here, instead of looking at fluid ization has shown previously, you're now
0:16:15   dealing with powder tumbling around in a drum. That can that can assume many types of forms. Most of
0:16:22   these work for for doing particle it'll be processing but of course you don't want the powder
0:16:29   sticking to the walls.
0:16:35   Yeah, as far as analysis of these powders, really more, the more important part of this is now
0:16:45   application testing by the customer. And the question often arises as to does it matter if it's
0:16:52   really good informal L'd where you don't exaggerate any particles together?
0:17:02   And the answer is kind of a yes and no. Um even if the customer doesn't care or the application
0:17:10   isn't impacted by by agglomeration for example. Um It's very useful to maintain good L. D.
0:17:18   Processing because when you have nice con formal ah self limiting L. D. It really helps with
0:17:26   reproducibility and that's one of the main reasons too. To keep striving for doing proper LD, even
0:17:35   when it might not matter in some sense.
0:17:49   So the next thing to talk about is how to deal with difficult powders. So for example, on in the
0:17:57   middle here we show slugging behavior that happens with particularly sticky powders and that can be
0:18:05   seen if you just put flour into a fluid. Ized bed for example, and there's different ways of dealing
0:18:13   with that. Oftentimes just drying the material or doing some sort of pre treatment can consult the
0:18:19   fluid Ization challenges. We also have various full realization aids on our various tools including
0:18:27   and vibrating the whole the whole bed, impacting micro jets and even stirs.
0:18:37   And the other thing is that often times fluid ization changes as you introduce the different LD
0:18:45   precursors. So on the far right here we have phosphorus stuck inside a rotary drum and we were
0:18:56   discouraged about our ability to be to be able to process this until we hit it with the first team a
0:19:02   dose. And over the course of this dose, this this powder that was completely stuck to the walls and
0:19:13   turned into nicely rolling powder. And we were able to process this material
0:19:22   and as I mentioned earlier, we have multiple reactor geometries at that. Work better or worse with
0:19:30   various powders, not just the fluid bed and the rotating bed, but also occasionally, it's actually
0:19:37   okay to do a packed bed coding. And of course we're going to talk about LD when we spatial ale D.
0:19:42   When we do talk about scale up.
0:19:47   The other thing to consider is that we have to those hundreds of grams of precursors sometimes just
0:19:52   to do one ale decoding run on a kilo of nano powders for example. Mhm. So
0:20:04   yeah of course gases tend to be easy to dose but liquids and solids are more challenging as are
0:20:11   certain precursors like ozone with a limited lifetime.
0:20:17   So we can do direct dozing of precursors we can use um yeah precursors heated in bumblers. We've
0:20:25   developed a liquid injection technique and we've also dissolved precursors. And sometimes you can
0:20:33   also generate precursors in situ. And there's different ways of of doing the dozing. You can either
0:20:41   have insert your feedback control as with the mass spec or sometimes for a well established process.
0:20:50   You can just those a predetermined quantity of precursor each for each cycle and how you quantify
0:20:59   the amount of precursor you've introduced is also a bit of a challenge and has different um
0:21:06   solutions including flow metering and even grab a metric measurements.
0:21:16   So next we're going to Uh huh. Right, so here are the two lab scale particle LD systems we have for
0:21:25   sale. Prometheus is kind of a fully featured um coding development two That has um powder volumes
0:21:36   anywhere from about 10 ml to a leader. It allows high temperature processing and bumblers with
0:21:45   precursors that can be heated 250 200 C. You can do ozone LD processing and of course the Argha is
0:21:54   the very useful process development two. And Furthermore This one allows inert loading and unloading
0:22:03   of your substrate. The pandora rotary tool is a kind of lower cost, simpler to operate tool in some
0:22:12   ways. Typically we use it for smaller powder volumes down to Miller Leader. You can also do code
0:22:21   things that don't necessarily fluid eyes that well in a fluid bed such as extra dates for potala sis
0:22:28   or even small objects. And it also allows you to do static dozing since you no longer need uh fluid
0:22:40   izing. Gas, two fluid eyes the powder. So that's useful for very high aspect ratio um structures for
0:22:49   example. And the really nice thing about this tool is that the view port allows you to see the
0:22:55   powder inside as it's tumbling around and you can make sure that it's processing well and change to
0:23:04   those in conditions if necessary to to deal with that. It also has options like the Argus which of
0:23:10   course I highly recommend uh you can even put a Q. C. M. In there and there's a GMP compatible
0:23:19   versions of this tool as well.
0:23:23   All right. And finally we have stepped forward in our process where we go to industrial scale
0:23:32   particle L. D. Depending on your application that might meet tons per year tons per day or even tons
0:23:40   per hour of particles being coded. And the nice thing is we have lots of options um for for batch LD
0:23:51   you can scale up your fluid bed to to quite large sizes if you wanted to. But we also offer a large
0:23:59   rotary blender tool ethos. And this is a small prototype version of it on the right that we have
0:24:08   running right now. And we're doing some um actually some some rocket fuel development basically in
0:24:17   this tool. And there are larger drums available for that. We also have continuous and semi
0:24:24   continuous particle of the processing the oceans which I'll show in the next slide and deciding
0:24:31   between the different types of tools is often a question of LV film thickness and the surface area
0:24:40   of powder as well as of course um precursor properties and delivery and and cost
0:24:50   but oftentimes what people look at it is the cost of the process that is dominated by the capital
0:24:58   cost. We use commercial powder handling equipment of various types to convey the powder into and out
0:25:06   of the reactor. Um So that's usually not that extravagant. But precursor costs can become quite
0:25:17   important if you have a thick l fillmore, a very high surface area powders. And at other times
0:25:25   operating costs such as time and labor and utilities, especially the heating and cooling of the
0:25:30   powder can be the dominant driver. And and like I said, it really varies from application to
0:25:37   application,
0:25:40   and your added cost for coding a kilo of powder might be since cents per kilo or my bt dollars per
0:25:49   kilo or even even higher spending. It just really depends on on the
0:25:58   factors involved here. Also, when you're doing industrial processing powders, things like safety,
0:26:05   the reproducibility of the process and various regulations come into play and may also affect affect
0:26:13   the type of tool that you choose.
0:26:17   Uh Most importantly, the industry itself often determines what type of processing tool is most
0:26:26   appropriate based on how it how it fits into their existing processing line.
0:26:36   Finally, I want to show you special particle LD. So this is basically taking the special ale D. Kind
0:26:45   of methods that you may have seen on waivers and translating them to powder so we can actually drop
0:26:56   batches of powder through zones of precursor and purges and this pot system over on the right um
0:27:10   and do multiple ale. These cycles like that by by building multiple pots. And this other tool here,
0:27:20   Sir C is a continuous ailed process that is almost like a world or old tool for for powder in that
0:27:30   powder is continuously moving through different zones of purging and precursor A and precursor P.
0:27:39   And both of these have been shown to produce powder on the tons per day and even tons per hour type
0:27:47   of rate. Especially if you're only looking for a few LD cycles, which is often the case for for for
0:27:56   battery applications that we are heavily involved with.
0:28:03   So again, this this is showing the diagrams of the three different
0:28:09   large scale powder processing tools.
0:28:15   Since the previous pictures may not have been as clear.
0:28:21   Yeah, for more information on this kind of processing, definitely take a look at James. James has
0:28:28   talked from last year. That's in the PLD Summit Video Library. Oh and finally, to summarize, I hope
0:28:39   I have shown you how fortunate, you know, can provide that phase two in the South Park colorado, mm
0:28:50   for the gnomes who in this case no how to collect L. D. Coded powder but don't quite know how that's
0:28:57   going to be commercialize, able. And I'm Marcus Groner. I'd be happy to answer questions now or
0:29:05   online or hopefully see you in the future in our new location here at uh, thorton colorado
0:29:16   or at some other conference. Thank you.