Patent ID: 7972971

Claim:
A method for producing a microelectronic device comprising a plurality of Si 1-y Ge y based semi-conducting zones (where 0<y≦1) with different Germanium contents, comprising: a) forming at least one oxidation mask comprising a set of oxidation masking blocks on a substrate covered with a plurality of Si 1-x Ge x based semi-conducting zones (where 0<x<1 and x<y) having identical compositions, wherein the oxidation masking blocks respectively cover at least one semi-conducting zone of said plurality of Si 1-x Ge x based semi-conducting zones, wherein a plurality of said oxidation masking blocks have different thicknesses different materials, or a combination thereof; and b) oxidizing said plurality of Si 1-x Ge x based semi-conducting zones through said oxidation mask, inducing a delay in the oxidation of said plurality of Si 1-x Ge x based semi-conducting zones as a function of the thicknesses and compositions of said oxidation masking blocks, and thereby forming Si 1-x Ge x based semi-conducting zones comprising Si 1-y Ge y (with 0<y<1 wherein y>x) with different Germanium concentrations below said oxidation masking blocks.