Fabrication of a substrate comprising a useful layer on a support having high resistivity includes thermal treatment to precipitate interstitial oxygen in the substrate base

摘要

Fabrication of a substrate comprising a useful semiconductive layer on a support having high resistivity comprises: preparing a semiconducting substrate base containing interstitial oxygen; thermal treatment to produce precipitation of the interstitial oxygen; removing a surface layer of thickness from the substrate base; and forming the useful layer on the surface of the substrate base. Fabrication of a substrate comprising a useful semiconductive layer on a support having high resistivity, typically greater than 1 kOhm.cm, comprises: (a) preparing a substrate base of semiconducting material containing a controlled amount of interstitial oxygen; (b) performing thermal treatment to produce at least partial precipitation of the interstitial oxygen; (c) on the surface of the substrate base that is to receive the useful layer, removing a surface layer of thickness 0.5-10 microns; and (d) forming the useful layer on the surface of the substrate base, which forms the support. Stage (a) comprises: (a1) the production of a silicon ingot by a magnetic field applied Czochralski method; and (a2) cutting the substrate base from the ingot. Stage (b) is implemented so as to stabilize precipitated oxygen, and comprises at least two and preferably three thermal treatments at different, progressively increasing temperatures. Stage (c) includes polishing the surface of the substrate base. Stage (d) is achieved by transferring the useful layer from a donor wafer comprising Si, SiGe, SiC and GaN. Before stage (d) an insulating layer is formed on the useful layer and/or on the substrate base, so that the insulating layer is located between the useful layer and the substrate base after stage (d).