Thin film wafer transfer and structure for electronic devices
A method for wafer transfer includes forming a spreading layer, including graphene, on a single crystalline SiC substrate. A semiconductor layer including one or more layers is formed on and is lattice matched to the crystalline SiC layer. The semiconductor layer is transferred to a handle substrate, and the spreading layer is split to remove the single crystalline SiC substrate.
1. A method for wafer transfer, comprising:
forming a spreading layer on a single crystalline substrate, the spreading layer including a material having strong bonds in two dimensions and weak bonds in a third dimension, the spreading layer being spread to lattice match the single crystalline substrate;
growing a crystalline layer on the spreading layer such that the crystalline layer is lattice matched to the single crystalline substrate;
forming one or more semiconductor layers on the crystalline layer, wherein the crystalline layer includes SiC, the spreading layer includes grapheme and the one or more semiconductor layers includes GaN;
transferring the one or more semiconductor layers to a handle substrate; and
splitting the spreading layer along the weak bonds to remove the single crystalline substrate.
2. The method as recited in claim 1 , wherein the spreading layer includes one to five monolayers of graphene.
3. The method as recited in claim 1 , wherein the single crystalline substrate includes one of SiC, SiGe, a III-nitride, III-arsenide, and a III-phosphide.
4. The method as recited in claim 1 , wherein growing the crystalline layer on the spreading layer includes epitaxially growing the crystalline layer.
5. The method as recited in claim 1 , wherein the single crystalline substrate includes SiC and forming a spreading layer includes thermally decomposing the SiC to form a graphene spreading layer.
6. The method as recited in claim 1 , wherein forming the spreading layer includes epitaxially growing a graphene spreading layer.
7. The method as recited in claim 1 , wherein the one or more III-nitride layers form active layers for an electronic device.
8. The method as recited in claim 1 , further comprising reusing the single crystalline substrate for further processing.
9. A method for wafer transfer to form an electronic device, comprising:
forming a spreading layer on a single crystalline substrate;
growing a crystalline layer on the spreading layer to form a first contact layer such that the crystalline layer is lattice matched to the single crystalline substrate;
forming an active layer including one or more III-nitride layers on the crystalline layer, wherein the crystalline layer includes SiC, the spreading layer includes graphene and the one or more III-nitride layers includes GaN;
forming a second contact layer over the active layer, wherein the active layer is disposed vertically between the first and second contact layers;
transferring the second contact layer to a handle substrate; and
splitting the spreading layer to remove the single crystalline substrate.
10. The method as recited in claim 9 , wherein the spreading layer includes one to five monolayers of graphene.
11. The method as recited in claim 9 , wherein forming the active layer includes forming a multiple quantum well (MQW) structure.
12. The method as recited in claim 11 , wherein MQW structure includes a plurality of GaN/InGaN periods having a total thickness of less than about 100 nm.
13. The method as recited in claim 9 , further comprising reusing the single crystalline substrate for further processing.
14. The method as recited in claim 9 , wherein the first contact layer and the second contact layer are separated by a distance of 100 nm or less.
15. The method as recited in claim 9 , wherein the single crystalline substrate includes one of SiC, SiGe, a III-nitride, III-arsenide, and a III-phosphide.
16. The method as recited in claim 9 , wherein the single crystalline substrate includes SiC and forming a spreading layer includes thermally decomposing the SiC to form a graphene spreading layer.
17. The method as recited in claim 9 , wherein forming the spreading layer includes epitaxially growing a graphene spreading layer.
18. A method for wafer transfer, comprising:
forming a spreading layer, including graphene, on a single crystalline SiC substrate;
growing a crystalline SiC layer on the spreading layer;
forming a semiconductor layer including one or more layers lattice matched to the single crystalline SiC substrate;
transferring the semiconductor layer to a handle substrate; and
splitting the spreading layer to remove the single crystalline SiC substrate.
19. The method as recited in claim 18 , further comprising reusing the single crystalline SiC for further processing.
20. The method as recited in claim 18 , wherein the single crystalline substrate includes SiC and forming a spreading layer includes one of: thermally decomposing the SiC to form a graphene spreading layer; and epitaxially growing a graphene spreading layer.