Integrated Circuits with Components on Both Sides of a Selected Substrate and Methods of Fabrication

A method for forming integrated circuits (ICs) comprising a first circuit layer and a second circuit layer, comprising:

• a) forming the first circuit layer from an active layer of a silicon-on-insulator (SOI) wafer, wherein the SOI wafer comprises the active layer, a buffer layer coupled to the active layer, and a silicon substrate coupled to the buffer layer;
• b) removing the silicon substrate from the buffer layer;
• c) forming the second circuit layer on a second surface of the selected substrate;
• and,
• d) coupling the buffer layer to a first surface of a selected substrate.

A method for forming integrated circuits (ICs) comprising a first circuit layer and a second circuit layer, comprising:

• a) forming the first circuit layer from an active layer of a silicon-on-insulator (SOI) wafer, wherein the SOI wafer comprises the active layer, a buffer layer coupled to the active layer, and a silicon substrate coupled to the buffer layer;
• b) removing the silicon substrate from the buffer layer;
• c) forming the second circuit layer on a second substrate;
• d) separating the second circuit layer from the second substrate;
• e) coupling the buffer layer to a first surface of a selected substrate;
• and,
• f) coupling the second circuit layer to a second surface of the selected substrate.

A method for forming integrated circuits (ICs) comprising a first circuit layer and a second circuit layer, comprising:

• a) forming the first circuit layer from an active layer of a silicon-on-insulator (SOI) wafer, wherein the SOI wafer comprises the active layer, a buffer layer coupled to the active layer, and a silicon substrate coupled to the buffer layer;
• b) removing the silicon substrate from the buffer layer;
• c) forming the second circuit layer on a second substrate;
• d) separating the second circuit layer from the second substrate;
• e) coupling the second circuit layer to a second surface of the selected substrate;
• and,
• f) coupling the buffer layer to a first surface of a selected substrate.

A method for forming integrated circuits (ICs) comprising a first circuit layer and a second circuit layer, comprising:

• a) forming the first circuit layer on a first substrate;
• b) separating the first circuit layer from the first substrate;
• c) coupling the first circuit layer to a first surface of a selected substrate;
• and,
• d) forming the second circuit layer on a second surface of the selected substrate.

A method for forming integrated circuits (ICs) comprising a first circuit layer and a second circuit layer, comprising:

• a) forming the first circuit layer on a first substrate;
• b) separating the first circuit layer from the first substrate;
• c) forming the second circuit layer on a second substrate;
• d) separating the second circuit layer from the second substrate;
• e) coupling the first circuit layer to a first surface of a selected substrate;
• and,
• f) coupling the second circuit layer to a second surface of the selected substrate.

An integrated circuit (IC), comprising:

• a) a first circuit layer, formed on an active layer of an SOI substrate;
• b) a buffer layer, wherein a first surface of the buffer layer is coupled to the active layer of the SOI substrate;
• c) a selected substrate, wherein a first surface of the selected substrate is coupled to a second surface of the buffer layer;
• and,
• d) a second circuit layer coupled to a second surface of the selected substrate.