I have 3 substrates
p-si (0.001-0.01 ohm cm), n-si (1-10 ohm cm) and glass.
When I use si wafer as a substrate during RF sputtering I have noticed that the edges are not coated and coating is near the center part of the substrate. I cannot give any tape for thickness measurement also. Will this problem be in case of glass substrates too. Is it possible to bias a glass substrate?
Yes, glas can be used, depending on the expected property of the product.
If you are using glass...bear in mind the low thermal and electrical conductivity of the glass.., also have it in mind that randomized composite is not achievable, however layered composites is possible.
Coverage area of the substrate during sputter deposition is determined by the size of the sputter target used. Are you using 1-inch or 2-inch sputter target? What is the dimension of the Si substrate? You can also check the alignment of the target with respect to the substrate position; this is more important if you have more than one targets in place (e.g. confocal arrangement). RF sputtering on glass should not be a problem.
A few things are not clear in your question
1) Well in general putting a bias requires substrate to be conducting.
2) In case you are using a glass substrate you need a metallic coating on it
2) I hope you are talking about dc bias.
3) +ve bias or -ve bias, with respect to ground.
---------------------------------------
During rf sputtering with the presence of rf plasma, lot of care has to be taken to put bias onto the substrate. If proper electrical care is not taken, it can lead to damaging consequences.
During rf sputtering:
Any wire entering into the chamber from external source (For example)
i) for the purpose of measuring temperature (say thermocouple wires),or
ii) wires for substrate heating to pass current into the substrate heater, or
iii) wires coming from outside to put a bias (dc or ac) onto the substrates
will create a problem. disturb the impedance matching. Allows rf leakage through the wires into your external power supplies and spoil them.
To put any bias onto the substrate platform (or substrate), the substrate platform should be electrically isolated.
Bias from external sources should be applied through an isolation transformer to prevent rf interference with your external (power supply, or electronics).
The question was slightly unclear whether it is dealing with "Bias sputtering", or applying a bias (+ve/-ve DC/AC bias) on a substrate.
Bias sputtering is totally different process compared to simple rf sputtering.
A special arrangement is needed in the rf power supply to do RF bias sputtering, and adjusting the power split between the target and the substrate.
Yes, for Bias sputtering you can use glass, provided the rf power splitting is chosen carefully, and low power bombardment of the glass substrate should be selected., otherwise normal glass substrate will crack as Dr. Rana has pointed out in his reply. Instead of normal borosilicate glass, quartz is a better choice.
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology
- Nanostructures
- Thin Films