Molecular beam epitaxy: Another technique in research stage is called molecular beam epitaxy (MBE). This is done in very high vacuum (10-8 Pa). The material to be deposited is heated and the molecules (or atoms) will evaporate. The wafer is kept at a lower temperature. Due to the high vacuum, the molecules will have a long mean free path and will not interact with one another. They will deposit on the wafer and due to the slow growth rate, it is possible to get single crystal growth using MBE. The main disadvantage of MBE is that it is a very slow process and hence is not yet suitable for implementation in semiconductor industry.

Copper deposited by PVD or CVD method has slightly higher resistance than the film deposited using electrochemical methods. Hence electrochemical deposition (ECD) is used for coating the wafer with copper.