A method of growing III-N material on a silicon substrate includes the steps of epitaxially growing a single crystal rare earth oxide on a silicon substrate, epitaxially growing a single crystal rare earth nitride on the single crystal rare earth oxide, and epitaxially growing a layer of single crystal III-N material on the single crystal rare earth nitride. The receiving tank includes a first chamber that receives arriving water and is under ambient pressure, and a second chamber that is connected to the first chamber and is under vacuum, into which the water collecting in the first chamber is aspirated and from which the water is eventually drained. Then, the source electrode coupled to the higher concentration source region is formed. The PME separator includes a polyimide, at least one lithium salt and at least one solvent all intermixed.