Waterloo Advanced Technology
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10 Nov 2017 - LEO
resuming user service
- We are bringing the LEO back online and into user service.
The probe current is lower than spec but it is extremely stable (with
variation less than 5%). The image quality is also good.
Please limit the EHT to not greater than 15 kV
(as anything higher than 15 kV could cause arcing and kill the gun).
As we will be resetting the user data base, please see Nina or Lei if you
experience any problem logging on. We thank you for your cooperation and
for your patience during the past several difficult months as we tried to
fix this SEM.
30 Oct 2017 - Removing users not showing up - As the Ultra is becoming rather busy lately, we wish to remind all users to show up at the reserved time. Please remove your booking at least 24 hours before the reserved time (if your sample is not ready), so as to allow other users enough time to rebook the released time. Please be considerate to your fellow users, whose works are just as important and as urgent as yours. We have begun to remove access privilege from users whom we have not been able to convince to adhere to the reserved booking. We thank you for your cooperation.
26 Oct 2017 - LEO returning to user service, maybe? - The LEO suffered a filament loss in July - this was the shortest filament lifetime that this machine has experienced, about 5 months. The cause appeared to be a very tiny leak just above the column valve (V3). Various attempts have been made to fix this leak. To minimize the effect of this tiny leak on the filament, we have also rebuilt the ion pump in the gun chamber to try to increase local pumping in this region (which has caused a substantial delay). A new filament was activated on Tuesday, and we are currently running some stability tests. If the source is stable, we will release the machine for user service hopefully by Nov 2. We thank our loyal users for their patience during this challenging time.
To our users with powder samples, we wish to remind them that one does not really need tons of samples to do SEM. Powders should be uniformly spread over a 1 mm x 1 mm area (in a layer a few microns thick) and attached securely onto the carbon tape. We definitely do not need powders spreading over an area larger than 1 mm x 1 mm and/or in a layer thicker than 10 microns. Here, we should remember: LESS is MORE, b/c:
(a) A finely focussed electron beam (<10 nm dia.) hitting any sample (especially the "gassy" ones) at high energy will cause local heating/interaction that leads to rapid gas desorption, which will cause the filament (sitting at the EHT voltage) to arc (the filament will not survive above 5x10-9 mB). Field-emission filament will not be able to handle a lot of arcings like that, which will shorten its lifetime significantly. So, the less samples that one uses, the more stable is the machine.
(b) Powder samples that are too thick (or not securely attached to the carbon tape) will also lead to partial charging. This is b/c the electron beam typically penetrates a few microns, creating secondary electrons that are finding their way to the carbon tape. If the sample is too thick, these secondary electrons stay inside the bulk and the sample will charge up, leading to bad images.
(c) More samples in the chamber will lead to a poorer vacuum, and it will take a longer time to pump the system down to the acceptable operating vacuum condition. Less gas in the chamber and less gas desorption from the sample (as induced by the high-energy electron impact) will also improve image quality.
7 July 2017 - LEO down for the next four weeks - Other SEMs available - During the filament change of the LEO in June, we have encountered a tricky vacuum problem in the gun. The engineer returned this week but the problem remained unresolved. We will need to acquire some more parts before we could go further. This unfortunately will take some time (4-8 weeks). In the meantime, all SEM users are encouraged to contact Nina re use of the Ultra (ultrahigh resolution SEM) or Quanta (Environmental SEM), as appropriate. Some users will require additional training (from Nina for the Ultra, and from Lei for the Quanta). For the EBL users who depend on the LEO Nabity EBL system, we are releasing the Merlin (state-of-the-art SEM) with advanced Fibics NPVE nanofabrication tool. Lei is in the final stage of making the workflow more robust. Please contact him for training. We apologise for any inconvenience and we hope the current EM solution will help to advance the research of our loyal users.
31 May 2017 - Charge compensation in ESCALab - The Thermo engineer has resolved the charge compensation problem in the ESCALab. The system is now close to spec and capable of handling insulating samples. Highly outgassing samples (containing S and/or P) remain a challenge for XPS facilities and UHV systems in general., because S will corrode the lens elements over time, rendering the electron optics ineffective. With the assistance of a few user groups, we are developing a few pre-analysis sample cleaning protocols to see if we can at least reduce this type of contamination issues.
31 May 2017 - High kV problem in LEO - The engineer is scheduled to be on site by mid June to see if we can resolve the high kV arcing problem. Please hang tight. In the meantime, we encourage the users to try out the ESEM and/or the Ultra.
21 Feb 2017 - Calendar
booking becoming unreliable
We have noticed that an increasing number of users signed up the tool but
failed to show up. This is unacceptable, because the no-show booking
is blocking another user from using the machine. Some deleted their
bookings a few hours or a few minutes before the reserved time slots and
hoped that no one noticed. Well, we do notice, and we are keeping
track of who is doing this. Those who continue to disregard the
honour system will soon lose their machine privilege.
the WATLab FAQ regarding
booking cancellation policy.
If you are not sure whether your samples will be ready at the time of your booking, we suggest that you do not book ahead. Instead, you should try a "walk-in", i.e. check if the machine is free at the time you wish to use the tool and if it's free, then you can just go ahead and use it until the next reserved time. If you make a reservation on the calendar, we and all other users expect you to show up.
Feb 2017 - LEO resuming normal operation - Ultra resuming
The FE source in the LEO has been replaced and the system appears to be
functioning close to spec. There is a minor change to the setup.
The EDS system still needs some calibration (use at your own risk) but the
SEM imaging is good.
Please see one of WATLab staff before startup.
24 Jan 2017 - LEO system down - After 2.9 year, the FE source in the LEO is finally gone. We have contacted the engineer and help is on its way. Hopefully, we can get this back up as soon as possible. Please watch this space for further news. In the meantime, please see if your work can take advantage of the environmental SEM.
Looking for an exciting graduate or undergraduate research project in nanosciences and nanotechnology? Please contact firstname.lastname@example.org for further information.
TOOLSET & SERVICE
Established with funding support from Canada Foundation for Innovation and the Province of Ontario in 1999, WATLab is the first multidisciplinary materials research centre in Canada's Technology Triangle. WATLab offers a complete toolset for advanced materials research and emerging technology development. Most of our instrument systems are state-of-the-art and some are unique in Canada, and they include:
We offer pay-per-use service for both academic and industrial users at competitive rates, with our expert operators providing sample characterization measurement (and analysis). For a selected number of tools (e.g. SEM), we also provide training to allow the users to access the tools through a self-serve booking system.
To submit samples for analysis, please fill in Form A (and Form B for University of Waterloo users) above, and contact the respective technical specialists. For all other enquiries and guided lab tours, please contact manager .
KNOWLEDGE BASE Inside look at LEO chamber |
CORE RESEARCH aT WATLAB Research news to come...