How is the oxygen contamination reduced?
ICP and microwave plasma sources use dielectric windows, often made of quartz, to transmit the electromagnetic field that maintain the plasma. The plasma can attack these dielectric windows releasing oxygen, which is incorporated in the films. In contrast the hollow cathode source is all metal so that oxygen contamination is greatly reduced.How much can the oxygen be reduced by?
By orders of magnitude is some cases, it also helps to have a loadlock system and a good growth preparation strategy. It should be noted that for polycrystalline films, oxygen from the atmosphere can often diffuse down grain boundaries (after growth) so that much of the residual oxygen content may be from this.How are higher growth rates achieved?
The hollow cathode source uses a lower voltage potential than ICP sources to achieve a high electron density. This means that there is less acceleration potential and the species created are less damaging. For many ALD processes this results in a greater Growth Per Cycle (GPC) value. For instance, for AlN growth, up to a 74% increase in GPC has been noted by one customer. Lower oxygen contamination may also help in some cases, since the presence of oxygen can sometimes poison the growth front of some nitrides.Can you provide custom solutions?
Yes. Apart from the Fiji ALD conversions nearly all our plasma sources are customised. We work closely with our customers to achieve the best solution.Is the hollow cathode plasma source any good for oxygen?
Yes. We’ve carried out trials with customers to achieve some very impressive results with oxygen plasmas. The hollow cathode plasma source is a very cost competitive solution in this circumstance.Are other plasmas possible?
our standard configuration, nitrogen, oxygen, ammonia, hydrogen, argon and nitrous oxide have all been trialled to date. Other plasma chemsitries may also be possible. Please contact our technical staff for your plasma requirements.Can we do the Fiji ALD conversion ourselves?
Yes, some of our customers have done this with us helping them by email and skype. However we can also provide an installation service for those who’d prefer this.Can Meaglow help with carbon contamination problems?
Yes, we have speciallised IP which can be applied for low temperture plasma based deposition and has been shown to reduce carbon contamination for some growth systems by orders of magnitude.
Have a question about the Meaglow Research Reactor?
Contact us directly as the solution is quite customizable.