Method for manufacturing localised GeOI structures, obtained by germanium enrichment

摘要

The process of producing germanium-on-insulator (GeOI) structure by germanium enrichment of a silicon germanium (SiGe) layer (38) supported by silicon oxide layer (39), comprises forming the initial layer of monocrystalline SiGe doped on a support substrate (31), forming pores in the initial layer of doped SiGe, forming a first layer of continuous monocrystalline silicon on the porous SiGe layer, forming a monocrystalline SiGe layer for germanium enrichment on the silicon layer, and forming a second layer of monocrystalline silicon on the SiGe layer for germanium enrichment. The process of producing germanium-on-insulator (GeOI) structure by germanium enrichment of a silicon germanium (SiGe) layer (38) supported by silicon oxide layer (39), comprises forming the initial layer of monocrystalline SiGe doped on a support substrate (31), forming pores in the initial layer of doped SiGe, forming a first layer of continuous monocrystalline silicon on the porous SiGe layer, forming a monocrystalline SiGe layer for germanium enrichment on the silicon layer, forming a second layer of monocrystalline silicon on the SiGe layer for germanium enrichment, forming a mesa in the stack constituted by the first silicon layer and second silicon layer, depositing protection spacers (36) on the flanks of the mesa, and oxidizing the SiGe porous layer to obtain the silicon oxide layer doped by germanium. The silicon oxide layer is doped with germanium by oxidation of a porous layer of SiGe. The concentration of germanium in the silicon oxide layer is such that: the concentration lowers the flowing temperature of the silicon oxide layer below the oxidation temperature for enrichment of germanium in the SiGe layer; and the molar percentage of germanium oxide with respect to the composition of the doped silicon oxide layer is 4-13 m/o. The porous SiGe layer is obtained by electrochemical etching of a doped SiGe initial layer in a hydrofluoric acid solution. An independent claim is included for a semiconductor structure.