| 摘要 |
Transfer of successive thin layers of semiconductor from a donor wafer (30) to a receiver wafer involves adhering the donor wafer to a receiver wafer at the free surface of the donor layer (10) of the donor wafer, and transferring a thin semiconductor layer (10) from the donor wafer to the receiver wafer by separating at an embrittlement zone in the donor layer. Transfer of successive thin layers of semiconductor from a donor wafer to a receiver wafer comprises: (a) assembling a bulk wafer comprising a semiconductor material with a support to form a mechanically stable assembly consisting of a donor wafer (30) comprising a 100-300 micron thick donor layer (10) of semiconductor material and a 100-300 micron thick support layer (20); (b) creating an embrittlement zone at a controlled depth in the donor layer (10); (c) adhering the donor wafer (30) to a receiver wafer at the free surface of the donor layer (10) of the donor wafer (30); (d) transferring the thin layer of semiconductor material from the donor wafer (30) to the receiver wafer by effecting separation at the embrittlement zone; and (e) repeating operations (b) to (d) without damaging the support layer (20) of the donor wafer (30). Operations (a) to (d) are repeated a maximum number of times chosen as a function of the thickness of the donor layer (10) and the depth of the embrittlement zone. Stage (a) is realized by molecular adhesion or high temperature welding between the polished surfaces of the bulk wafer and the support. Stage (b) is realized by implantation of gaseous species. Stage (c) is realized by molecular adhesion. Stage (d) is realized by applying thermal and/or mechanical stress. The semiconductor material is a single crystal semiconductor, preferably Si, SiC, and wide-gap mono- or poly-metallic nitrides, especially GaN. The support is selected from a group comprising the same material as the single crystal, but which is a single crystal of lower quality, or is polycrystalline, or is of different poly-type. The support layer (20) is selected from Si, GaN, SiC, GaN, SiC, AlN and sapphire. An Independent claim is given for a process for fabrication of the donor wafer. |
