Method for making a device comprising layers of planes of quantum dots
AssigneeFrance Telecom
InventorsDaniel Bensahel, Yves Campidelli, Caroline Hernandez
Life of this patent
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Abstract
A method for forming on a Ge or Si monocrystalline substrate successive Si/Ge, Si/SiGe, or Si/SiGe/Ge layers for a Ge substrate and inversely for a Si substrate is described. Electrochemical treatment of the stack of layers to make the layers porous and form therein residual crystallites is also described. The invention may be used to provide devices having layers of planes of quantum drops.
Claims18
A process for fabricating a device comprising a stack of quantum box planes, wherein the process comprises:
- forming a stack of successive, alternating single-crystal layers of Si/Ge, Si/SiGe, or Si/SiGe/Ge on a single-crystal germanium substrate or a stack of successive, alternating single-crystal layers of Ge/Si, Ge/SiGe, or Ge/SiGe/Si on a single-crystal silicon substrate;
- and
- the electrochemical treatment of the stack of single-crystal layers in order to make the layers porous and to form therein residual crystallites constituting quantum boxes, wherein the porous Ge or SiGe layers have a porosity greater than the Si layers.
A device comprising a stack of quantum box planes on a substrate, wherein the quantum box planes consist of successive, alternating porous single-crystal layers of Si/Ge, Si/SiGe, or Si/SiGe/Ge formed on a single-crystal germanium substrate or successive alternating porous single-crystal layers of Ge/Si, Ge/SiGe, or Ge/SiGe/Si formed on a single-crystal silicon substrate, wherein the porous single-crystal layers are formed by electrochemical treatment of a stack of single-crystal layers, and wherein the porosity of a first layer obtained by the electrochemical treatment is substantially different than the porosity of a second layer obtained by the electrochemical treatment.
A device comprising at least one quantum box plane formed in a germanium or SiGe alloy layer between two SiO2 layers.
A method for fabricating a device comprising:
- forming a stack of successive, alternating single-crystal layers of Si/Ge, Si/SiGe, or Si/SiGe/Ge on a single-crystal germanium substrate or a stack of successive, alternating single-crystal layers of Ge/Si, Ge/SiGe, or Ge/SiGe/Si on a single-crystal silicon substrate;
- electrochemically treating the stack of alternating single-crystal layers to make the single-crystal layers porous;
- and
- electrochemically oxidizing the porous single-crystal layers, which converts the porous silicon layers into insulating SiO2 layers and forms Ge or SiGe alloy quantum box planes between the SiO2 layers.
Dependencies are inferred from the claim text.