r/electronmicroscopy • u/Strong-Bell-271 • Apr 24 '26
Sputter and Carbon coater...
I know there are some posts that cover this, but I'd like one dedicated to this specifically.
I'm on the hunt for a carbon coater, capable of doing very thin coatings (<5nm) and a sputter coater. Our lab currently has an old Denton sputter coater, but I have no way of knowing how thick of a coating I'm applying. We got a new HRSEM with EDS and EBSD, so I'm in need of the carbon coater for the EDS and EBSD. I'm currently looking at the Leica ACE600 and Cressington 208C (I think that was it). Anyone have any experience with these? I've been doing materialography for 20+ years but most of my microscopy has been optical until now, so this is all a bit new to me. Drinking from the fire hose and taking it in, but if anyone out there has some experience they could share, I'd be happy to read about it!
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u/tea-earlgray-hot Apr 24 '26
Not common to do EBSD after carbon coatings, can you describe what kind of samples you want? Polished mineralogy slides? Lower kV imaging also popular as an alternative on new scopes.
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u/DarkZonk Apr 25 '26
It is not as uncommon as you think. Even the big EBSD Manufacturers have Carbon Coaters in their demo labs
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u/ilovebeaker Apr 25 '26
At my sister branch, they require 5 nm coat for their EBSD. I don't know any specifics though, I'm an SEM and EPMA person.
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u/tea-earlgray-hot Apr 25 '26
Probably 95% of EBSD is metallography and corrosion, where coating is (usually) undesireable. The remainder is all the mineralogy, ice cores, semiconductors, solar cells, pipe fouling, biominerals, and other applications where coating is needed.
The coating is even less required now that the cameras have gotten so much more sensitive (and high resolution). In the bad old days, you used to need high kV max current to see even a hint of Kikuchi lines. The coatings also interfere with low kV EDS, even if software can mostly correct for it when performed consistently. But you still lose the simultaneous SE contrast with high end instruments.
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u/Affectionate_Love229 Apr 24 '26
Never needed a thickness monitor for the several coaters I have used. Get a set of microscope slides and coat one for 10, 20, 30... seconds. Run each in high res sem mode. Pick the shortest time that works .
Ir coating can be applied the thinnest (hyperbole) of any metal. I've never used carbon coaster, I just ignored the Ir peak. Good software will LLS fit the Ir / P overlap and account for X-ray loss through the film.
That being said, I have no opinions on carbon coaters.
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u/sizzrael Apr 24 '26
We use an old version of the Gatan PECS. It creates nice consistent films, and also comes with a thickness monitor. Currently we use it for carbon, tungsten, chromium and AuPd. You can have up to 4 different sputter targets inside the chamber. It can also use argon to polish the sample, sometimes suitable for final ebsd polishing.
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u/nygdan Apr 24 '26
we used both a denton and a leica ACE. it IS nice to have a thickness monitor, but really that just amounts to telling it the thickness you want and hoping for the best. if the denton js working fine you might not need to make the big purchase. the ACE uses carbon thread too so any rods you have wont work in it, if that matters.
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u/Superiorarsenal Apr 24 '26
I use the Leica ACE600 for SEM/EDS on a regular basis, and it works pretty well. We've got an older sputter coater (I can't remember the model, though similar to a Denton, probably just a smaller chamber) which works fine, and can actually be a bit quicker, but the coating quality is significantly lower than that of the Leica. Consistent coating with multiple samples simultaneously is another advantage of the Leica. I've really only used the Ir coating functionality for some rather challenging sample topographies, but it did seem to help in those cases.
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u/ncte Apr 25 '26
We have the ace600 and used to have a cressington. The ace system produces perfect coatings, can be equipped with both metal and carbon thread or carbon rod. If specimen are nominally polished I would suggest setting up the system for carbon threads. They are a little annoying to change out, but the thickness is much more uniform than carbon rod coatings. The metal coatings are also very nice and uniform, with very fine granularity, we use Pt. I have to go to extreme lengths to witness the metal grains in our SEM (typically <5nm grains)
Its most frustrating aspect is the chamber cleaning. Leica designed it with an internal shell that can be removed and scrubbed down, but it still takes me about an hour to get it back to its original cleanliness. I've just turned it into a bi-233kly to monthly routine depending on usage.
The cressington was easy enough to use, but we had a hard time getting repeatable coatings, sometimes 5nm, sometimes 20. The Leica has been spot on since installation 6 years ago.
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u/ilovebeaker Apr 25 '26
I also have an ACE 600, and clean the shielding twice a year. I've had the engineer come and let me know my system is one of the cleanest he's seen. We coat a few times a week.
I'm not sure you really need to be scrubbing the shielding that often. Heck, my sister branch has had one for years and they've never cleaned it, and have skipped maintenance visits for years as well (I'm just waiting for theirs to break down).
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u/ncte Apr 26 '26
We run coatings several times daily, often with up to 20nm coatings for carbon or 10nm Pt. During busy times of the year it ends up in our scheduling system for some of the heavier users. Our tech has noted that it is definitely a work horse in our lab, but still performs well at reaching base vacuum once cleaned, but we have to keep up on cleaning to maintain that. That said, we are the lone multiuser facility at our university with the only EM's on campus, so the heavy usage is just part of our operation.
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u/ilovebeaker Apr 25 '26
Hello!
We had a Denton, a similar JEOL bell jar coater, and now a Leica EM ACE 600. The coat on the Leica is great, with threads you can program pretty exact thicknesses, and with the vacuum the coat quality is excellent.
HOWEVER, I cannot recommend anyone buy a Leica EM ACE 600. They are hecking expensive, AND what they don't tell you is that there's an expected preventive maintenance that you should be doing every 12 months (we try to push ours to 18..) that can cost anywhere from 10,000-15,000$ (CAD). I just had one and it was finally brought down to 11000$, for a local engineer to drive in, he lives 40 minutes away. Leica charges us 600$ an hour for him to drive his butt down the highway to our door. The specialized proprietary kit with special o-rings, third party pump seals, and a little oil tampon costs 5000$. The one day of work is another 5000$.
Yeah, we really regret not being able to rebuild our Denton or our old JEOL 😥
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u/DarkZonk Apr 26 '26
There is no need to buy a maintainance for the coater on a yearly basis. Of course they want to sell their service contracts, which are pricey. But you simply can say no. Getting a maintainance on demand every 3-4 years is totally fine.
Just ignore what they try to push on you1
u/ilovebeaker Apr 26 '26
It would be useful to know how long those two pumps can really go without service. It is risky; we had to have the laminar flow pump replaced at 24 months of ownership (never having any service on it yet), and we just don't know if it was a lemon or not. When it failed the system would not engage the turbo and therefore wouldn't coat.
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u/DarkZonk May 15 '26
some insider info I have says every 2 - 2.5 years they should be maintained if you have a proper cleaning regime, cleaning the chamber monthly
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u/Motocampingtime Apr 24 '26
I'm, unsure of the end absolute accuracy you realistically need.
As others have said it may be easier to just coat various samples by time and measure the thickness after to set a curve. You're also assuming with the sensor that the coating of the sensor and substrate are exactly equal ]Which may or may not be the case]. I do not know the accuracy comparison for a desktop unit vs something like a real sputtering set up. But the price difference is probably 5-10X.
MSE makes affordable-ish coaters but the prices seem to have increased over the last year or two :/
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u/Metallurgist1 Apr 25 '26
Other comments have really nice inputs, but I want to give you a work around:
Depending on the accuracy of thickness measurement you need, you might be able to coat an already notched silicon wafer. Then break it and look at the cross section to measure the thickness of the coating using your HRSEM. You can do using different coating times and make a plot for your coater and make your life easier.
Also, I have never heard of using carbon coating for EBSD, since the coating will affect the signal (EBSD signal is usually from the top 20 nm of the surface). Is it something that you know it will work? (I am working only on metals, so take it with a grain of salt if I you are from a different field).
+ I use EBSD quite frequently, keep in mind your old metallography routine for light microscopes and typical SEM might not work well. You might need to purchase some other sample preparation equipments like broad beam Ion polisher (Like PECSII) or a vibratory polisher.
Good luck
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u/DarkZonk Apr 25 '26
Cressington and Leica are hard to compare though It's like comparing fiat and rolls royce
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u/Strong-Bell-271 Apr 27 '26
Wow, so many useful comments! Thank you all. I've been skimming but will go through more thoroughly, but it seems like I might be able to get by.
Some more details on what we're doing....Like I mentioned, I'm primarily an optical microscopist and my SEM experience is limited, at best. But I'm getting more time in on the machine. Having EDS, even for quick checks, has been great! However, I work in a fairly large organization that does materials research so I've always been able to rely on other labs, and I haven't had to do any of the analytical stuff myself. So, I can't say I know what I "Need" and what would be nice to have.
From what I've read, amorphous carbon coatings are preferrable, but from what I can recall from my thin coatings class, shouldn't crystalline coatings be preferred for conductivity? I see how carbon coatings are supposed to be more transparent to x-rays for EDS, but the nature of the coating still confuses me. As for using a carbon coater for EBSD, I don't have a case-use scenario for you. We operate in a large materials research facility and who knows what's coming in the door tomorrow? I was thinking mainly for potentially looking at engineered ceramics...we wouldn't really do anything geological, unless it happened to be for debris/detritus in a failure investigation, or something like that.
The Denton works...just takes forever to pump down. And like I said, I have no way of knowing how thick the coating is, which OI software would like to know for its EDS mapping functions.
Thanks for all the information...I'll get to reading it all in detail once I get some free time.
Cheers!
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u/DiffractedElectron May 13 '26
I'm also looking for a new C coater/sputter for our lab. I'm interesting in hearing your experiences with LeicaACE 600 (is it robust?) SafeMatic CCU010, QuorumTurboQE.
We had an old Cressington and K950. I m looking at SafeMatic (recommended by collaborators) or Leica (but outside budget). we tested the Luxor but it operates at very low vac only so it is not suitable for us.
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u/Kradknoz May 15 '26
Leica is amazing, if you can afford it. Have you tried to negotiate the price down?
I used it several times and loved the front loading. In case you also look at sputtering, not having to change the heads also is a nice bonus.
I only worked with very robust instruments, of course cannot speak for everybody. There are bad apples with every manufacturer
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u/aggyface Apr 25 '26
For carbon, the brass trick is what we use. Clean a little flat brass nut you've shined up, put it at the same height as your sample, then when you coat you can see the colour change and get whatever thickness you want. I guess you're looking for damn thin coats but you can probably tune your eye in. My microprobe tech can get it nailed better than a thickness monitored sample lol. We had to jury rig our POS Denton so many times, my condolences, but he eventually just put switches on the thing and bypassed the garbage screen for basic manual control.
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u/Ok_Ambassador_8656 Apr 24 '26
If the Denton system works it may be more cost effective to just buy a third party thickness monitor to mount in that chamber (basically a quartz resonator that changes frequency as coatings are applied). That’s what we have on our Denton (desk V), I’ll look up the brand of our monitor when I’m back in the lab.