Method of forming epitaxial based integrated circuit
A method of growing an epitaxial semiconductor structure is disclosed. The growth and transfer are made using an epitaxy lateral overgrowth technique. The formed epitaxial film on an assembly substrate can be further processed to form devices such as solar cell, light emitting diode, and other devices and assembled into higher integration of desired applications.
1. A method of forming an epitaxial based integrated circuit comprising:
forming a thin film epitaxial layer situated within a non-semiconductor assembly template substrate having a top surface and bottom surface;
wherein said non-semiconductor assembly template substrate is comprised of a solid substrate board including a plurality of openings extending from said top surface to said bottom surface, and is adapted such that said thin film epitaxial layer at least partially fills said plurality of openings;
forming one or more semiconductor layers situated on said top surface and/or said bottom surface of said thin film epitaxial layer and defining one or more active devices;
wherein said solid substrate board for said non-semiconductor assembly template substrate is separate from a seed substrate used to grow said thin film epitaxial layer.
2. The method of claim 1 , wherein said thin film epitaxial layer can be grown laterally across a top surface of said assembly template.
3. The method of claim 1 , further including a step: processing said assembly template and thin film epitaxial layer as an integrated epitaxial packaged structure within a semiconductor processing apparatus to form active devices on said assembly template and/or said thin film epitaxial layer.
4. The method of claim 1 wherein said thin film epitaxial layer includes a graded composition throughout a thickness direction of said assembly template.
5. The method of claim 1 wherein a liquid phase epitaxial material used to make said thin film epitaxial layer is adapted with thermal characteristics matching said assembly template.
6. The method of claim 1 wherein said seed substrate used to make said thin film epitaxial layer is coupled to but detachable from said assembly template.
7. The method of claim 6 , wherein said seed substrate is detached by a shearing action.
8. The method of claim 6 , wherein said seed substrate is detached by a chemical etchant.
9. The method of claim 6 wherein said seed substrate can be re-used after said epitaxial layer is separated for growing a second epitaxial layer.
10. The method of claim 1 further including a step: forming one or more second separate thin film epitaxial layers on said thin film epitaxial layer.
11. The method of claim 1 further including a step: forming one or more second separate assembly templates and one or more separate thin film epitaxial layers on said thin film epitaxial layer.
12. The method of claim 11 wherein said one or more second separate thin film epitaxial layers and said thin film epitaxial layer include different dopant species.
13. The method of claim 1 wherein said thin film epitaxial layer has a multidimensional structure including lines and via interconnects.
14. The method of claim 1 , wherein said thin film epitaxial layer forms part of a p-n junction.
15. The method of claim 1 , wherein said thin film epitaxial layer forms part of an integrated circuit device.
16. The method of claim 1 further including a step of forming a sacrificial layer attached between a bottom surface of said assembly template and a top surface of said seed substrate.
17. The method of claim 1 further including a step of forming a spacer situated adjacent said assembly template and above said seed substrate used to make said thin film epitaxial layer.
18. The method of claim 1 further including a step: controlling heating and cooling of a liquid phase epitaxial material used to make said thin film epitaxial layer.
19. The method of claim 1 further including a step: controlling a side profile of said openings to be vertical, step recessed or sloped to any desired angle.
20. A method of forming an epitaxial based integrated circuit comprising:
providing a seed substrate;
forming a sacrificial layer on said seed substrate;
forming a thin film epitaxial layer situated on said sacrificial layer and within a first non-semiconductor assembly template substrate having a top surface and bottom surface;
forming one or more semiconductor layers with a second non-semiconductor assembly substrate that is situated on said top surface and/or said bottom surface of said thin film epitaxial layer and defining one or more active devices;
removing said sacrificial layer so as to transfer said thin film epitaxial layer and said one or more active devices off of said seed substrate;
wherein after manufacture of the epitaxial based integrated circuit said seed substrate can be used for manufacture of a separate thin film epitaxial layer.
21. The method of claim 20 wherein a constant temperature lower than a melt temperature of a liquid phase epitaxial material is maintained at an interface to said seed substrate so that said liquid phase epitaxial material precipitates and grows epitaxially on said seed substrate.
22. The method of claim 20 wherein said first non-semiconductor assembly template substrate, said seed substrate and a melt situate for a liquid phase epitaxial material are independently temperature controlled.
23. The method of claim 22 wherein said first non-semiconductor assembly template substrate, said seed substrate and said melt situate are controlled to have a temperature at or slightly above a bulk melting temperature of said liquid phase epitaxial material during a first phase of growing of said thin film epitaxial layer.
24. The method of claim 23 wherein said first non-semiconductor assembly template substrate, said seed substrate and said melt situate are slowly cooled to have a temperature at or slightly below a super-cooling point of said liquid phase epitaxial material during a second phase of growing of said thin film epitaxial layer.
25. The method of claim 24 wherein said first non-semiconductor assembly template substrate and said seed substrate are further cooled to an ambient temperature after said separation during a third phase of growing of said thin film epitaxial layer.
26. The method of claim 20 wherein said thin film epitaxial layer includes a graded composition throughout a thickness direction of said first non-semiconductor assembly template substrate.
27. The method of claim 20 wherein said thin film epitaxial layer has a multidimensional structure including lines and via interconnects.
28. The method of claim 20 wherein said seed substrate can be re-used for growing a second epitaxial layer with said second non-semiconductor assembly substrate after said thin film epitaxial layer is separated.
29. The method of claim 20 further including a step: controlling a side profile of plurality of openings to be vertical, step recessed or sloped to any desired angle.