| abstract |
Proposed is a layer structure (1100, 1030) comprising a crystalline piezoelectric III-N layer (1110, 1032) epitaxially grown over a metal layer which is epitaxially grown over a rare earth oxide layer on a semiconductor (1102, 1002). The rare earth oxide layer includes at least two discrete portions (1104, 1004), and the metal layer includes at least one metal portion (1108, 1006) that partially overlaps adjacent discrete portions, preferably forming a bridge over an air gap (1008), particularly suitable for RF filters. |