A duplexer is proposed with a substrate which has at least one patterned metallization plane and on which, at least to some extent, a transmission path and a reception path are arranged, both of which are connected to an antenna connection. The semiconductor layer is disposed on a principal surface of the conductive layer and forms a heterojunction with the conductive layer. 6 at 550 nm, and said exit medium being defined as follows 1. The method includes providing a non-rotatable conditioning member configured to engage the polishing pad. The wafer further has a substantially planar intrinsic gettering zone of substantially pure semiconductor material and active gettering sites positioned between the first and second layers formed by implanting ions of the semiconductor material through the first layer of monocrystalline semiconductor material. The tier assignment may also be preserved so that the current data can be appropriately assigned in the future.