Patent ID: 7989327

Claim:
Manufacturing method of a semi-conductor on insulator substrate from an SOI substrate comprising a superficial layer of silicon ( 13 , 23 , 33 ) on an electrically insulating layer ( 12 , 22 , 32 ), called a buried insulating layer, wherein a layer of Si 1-x Ge x ( 15 , 25 , 35 ) is formed on the superficial layer of silicon, wherein the method comprises the following steps: formation of a silicon oxide layer ( 16 , 26 , 36 ) on the layer of Si 1-x Ge x , etching of the stack formed by the superficial layer of silicon, the layer of Si 1-x Ge x and the silicon oxide layer, wherein the etching is carried out either up to the buried insulating layer to obtain an etched structure with at least one island ( 14 , 24 ) of said stack, or up to the superficial layer of silicon ( 33 ) to obtain an etched structure with at least one zone of silicon ( 33 ) and at least one island ( 34 ) of said stack, formation of a mask to protect against oxidation ( 17 , 27 , 37 ) on the etched structure, wherein the protective mask only leaves visible the silicon oxide layer ( 16 , 26 , 36 ) of the island, condensation of the germanium of the layer of Si 1-x Ge x on the island to obtain an island comprising a layer ( 18 , 28 , 38 ) that is either enriched in or composed of germanium, on the buried insulating layer, with a silicon oxide layer ( 19 , 29 , 39 ) on top of said layer ( 18 , 28 , 38 ) that is enriched in or composed of germanium.