Verfahren zum Ablösen eines scheibenförmigen Einkristalls von einem Grundkörper

The invention relates to a method for depositing a layer with a high degree of purity on a substrate within a vacuum chamber, comprising the method steps of: - a) crucibleless depositing of a block (1) consisting of an evaporation material within the vacuum chamber; - b) establishing an electrically conductive connection between the block and the voltage potential of the electrical earth of the vacuum chamber; - c) annular, locally delimited melting of the evaporation material within an inner region (3) of the surface of the block (1) by means of an electron beam, in that the - inner region (3) is passed over, beginning at its outer delimitation, by means of the electron beam on continuous or spiral paths with an increasingly smaller path radius; - d) evaporating evaporation material from a central region (5) of the inner region (3) by means of the electron beam; - e) evaporating evaporation material from the inner region (3) by means of the electron beam and depositing a layer on the substrate.