Epitaxy level packaging
A method of growth and transfer of epitaxial structures from semiconductor crystalline substrate(s) to an assembly substrate. Using this method, the assembly substrate encloses one or more semiconductor materials and defines a wafer size that is equal to or larger than the semiconductor crystalline substrate for further wafer processing. The process also provides a unique platform for heterogeneous integration of diverse material systems and device technologies onto one single substrate.
1. A method of processing an epitaxial wafer comprising:
arranging a plurality of compound semiconductor crystalline wafers and/or portions thereof into an assembly pattern;
wherein said plurality of compound semiconductor crystalline wafers and/or portions thereof are derived from wafers having at least one first nominal size including a first diameter;
mounting a separate assembly substrate over said assembly pattern, said separate assembly substrate having a second size, including a second diameter which exceeds said first diameter;
wherein said separate assembly substrate includes a plurality of through substrate vias extending from a top surface to a bottom surface which contacts said assembly pattern;
forming an epitaxial layer in said separate assembly substrate within said plurality of through substrate vias with an epitaxial process.
2. The method of claim 1 wherein said separate assembly substrate is a solid rigid disc.
3. The method of claim 1 wherein said epitaxial process comprises liquid phase epitaxy (LPE), hydride vapor phase epitaxy (HVPE), metal organic chemical vapor deposition (MOCVD), molecular beam epitaxy (MBE), or other epitaxial growth methods.
4. The method of claim 1 wherein said plurality of compound semiconductor crystalline wafers include at least two separate wafers comprised of two different materials.
5. The method of claim 1 wherein a reactor used for said epitaxial process forms an epitaxial layer on N separate compound semiconductor crystalline wafers at the same time.
6. The method of claim 5 wherein said reactor has a throughput rate that is approximately N times faster than that required by the reactor to form N separate epitaxial layers on N sequential compound semiconductor crystalline wafers processed at different times.
7. The method of claim 1 further including a step: etching said assembly substrate to form said through substrate vias to include one or at least two different profile shapes within said substrate.
8. The method of claim 1 further including a step: performing at least two separate etch operations on said assembly substrate to form two separate features of a profile of said through substrate vias.
9. The method of claim 1 wherein said assembly substrate includes two separate substrates bonded together.
10. The method of claim 9 wherein said two separate substrates include two different materials or one material of different thicknesses bonded by an interfacial adhesion layer.
11. The method of claim 1 further including a step: cutting said assembly substrate into pieces corresponding to an integrated circuit.
12. The method of claim 11 wherein an amount of epitaxial material required by a reactor to make said integrated circuit in said assembly substrate is less than that required to manufacture said integrated circuit directly on a crystalline substrate without said assembly substrate.
13. A method of processing an epitaxial wafer comprising:
arranging a plurality of pieces of a plurality of compound semiconductor crystalline wafers into an assembly pattern;
wherein said plurality of pieces have a surface area within an assembly substrate that is larger than that of a single one of said plurality of compound semiconductor crystalline wafers;
mounting a separate assembly substrate over said assembly pattern, said separate assembly substrate including a plurality of through substrate vias extending from a top surface to a bottom surface which contacts said assembly pattern;
forming an epitaxial layer in said separate assembly substrate within said plurality of through substrate vias with an epitaxial process.
14. The method of claim 13 wherein said mounting is done without atomic bonding between said separate assembly substrate and said assembly pattern.
15. A method of processing an epitaxial wafer comprising:
arranging a plurality of pieces of a plurality of compound semiconductor crystalline wafers into an assembly pattern;
wherein said plurality of pieces including materials from at least two different compound semiconductor types;
mounting a separate assembly substrate over said assembly pattern, said separate assembly substrate including a plurality of through substrate vias extending from a top surface to a bottom surface which contacts said assembly pattern;
forming at least two separate epitaxial structures in said separate assembly substrate within said plurality of through substrate vias with two separate epitaxial growth processes;
wherein said two separate epitaxial growth processes form layers on different ones of said at least two different compound semiconductor types of material.
16. The method of claim 15 wherein said plurality of pieces include adjacent pieces in said assembly substrate having said at least two different compound semiconductor types.
17. The method of claim 16 further including a step: connecting said adjacent pieces within an interconnect.
18. The method of claim 17 further including a step cutting said assembly substrate into discrete pieces corresponding to an integrated circuit, wherein said integrated circuit includes a heterogeneous circuit comprising at least two different materials types.
19. The method of claim 15 wherein a single reactor performs both of said two separate epitaxial growth processes.
20. The method of claim 15 said at least two different compound semiconductor types of material are processed within a common separate substrate.
21. The method of claim 15 wherein said mounting is done without atomic bonding between said separate assembly substrate and said assembly pattern.