Integrated rare earth devices
The invention includes a single chip having multiple different devices integrated thereon for a common purpose. The chip includes a substrate having a peripheral area, a mid-chip area, and a central area. A plurality of FETs are formed in the peripheral area with each FET having a layer of single crystal rare earth material in at least one of a conductive channel, a gate insulator, or a gate stack. A plurality of photonic devices including light emitting diodes or vertical cavity surface emitting lasers are formed in the mid-chip area with each photonic device having an active layer of single crystal rare earth material. A plurality of photo detectors are formed in the central area.
1. A method of forming a single chip having multiple different devices integrated thereon for a common purpose, the method comprising the steps of:
providing a substrate;
epitaxially depositing a contact layer with lower and upper differently doped portions on the substrate, the step of epitaxially depositing including one of depositing two portions of differently doped material and doping the contact layer after deposition to provide a lower portion with a first type of doping and an overlying differently doped portion;
epitaxially depositing a first insulating layer on the contact layer including one of a single crystal rare earth oxide and a single crystal rare earth silicate;
epitaxially depositing a first single crystal layer of semiconductor material on the first insulating layer;
epitaxially depositing a second insulating layer on the first single crystal layer, the second insulating layer including one of a single crystal rare earth oxide and a single crystal rare earth silicate;
epitaxially depositing a second single crystal layer of semiconductor material on the second insulating layer;
defining in the first single crystal layer of doped semiconductor material in conjunction with the second layer of insulating material and the second single crystal layer of doped semiconductor material at least one field effect transistor;
defining in the first single crystal layer of doped semiconductor material, the first insulating layer, and the contact layer at least one photonics device; and
defining in the first type doped lower portion and the differently doped type overlying portion of the contact layer at least one photodetector.
2. A method as claimed in claim 1 wherein the step of epitaxially depositing the contact layer on the substrate, the step of epitaxially depositing the first insulating layer on the contact layer, the step of epitaxially depositing the first single crystal layer of semiconductor material on the first insulating layer, the step of epitaxially depositing the second insulating layer on the first single crystal layer, and the step of epitaxially depositing the second single crystal layer of semiconductor material are all performed in situ.
3. A method as claimed in claim 1 wherein the steps of epitaxially depositing the first and second insulating layers including one of the single crystal rare earth oxide and the single crystal rare earth silicate includes depositing (RE 2 O 3 ) and (RE 2 SiO 5 ), respectively.
4. A method as claimed in claim 3 wherein the step of epitaxially depositing one of (RE 2 O 3 ) and (RE 2 SiO 5 ) includes depositing material in which the RE radical in (RE 2 O 3 ) and in (RE 2 SiO 5 ) includes (Gd 0.9 Er 0.1 ).
5. A method as claimed in claim 1 wherein the step of depositing the second single crystal layer of doped semiconductor material includes depositing one of silicon and germanium.
6. A method as claimed in claim 1 wherein the step of providing the substrate includes providing a silicon substrate.