Epitaxial lift off stack having a multi-layered handle and methods thereof
View Patent ↗Embodiments of the invention generally relate to epitaxial lift off (ELO) thin films and devices and methods for forming such films and devices. In one embodiment, a method for forming an ELO thin film includes depositing an epitaxial material over a sacrificial layer on a substrate, adhering a multi-layered support handle onto the epitaxial material, and removing the sacrificial layer during an etching process. The etching process further includes peeling the epitaxial material from the substrate and forming an etch crevice therebetween while maintaining compression in the epitaxial material. The method further provides that the multi-layered support handle contains a stiff support layer adhered to the epitaxial material, a soft support layer adhered to the stiff support layer, and a handle plate adhered to the soft support layer. In one example, the stiff support layer may contain multiple inorganic layers, such as metal layers, dielectric layers, or combinations thereof.
1. A method for forming a thin film material for at least one of a solar device, a semiconductor device, or an electronic device during an epitaxial lift off process, comprising: forming a contiguous epitaxial material over a sacrificial layer on a substrate; adhering a support handle onto the contiguous epitaxial material, wherein the support handle comprises a contiguous stiff support layer adhered to the contiguous epitaxial material, a soft support layer adhered to the contiguous stiff support layer, and a handle plate adhered to the soft support layer; removing the sacrificial layer during an etching process; and peeling the contiguous epitaxial material from the substrate while forming an etch crevice therebetween while maintaining compression in the contiguous epitaxial material during the etching process.
2. The method of claim 1 , further comprising removing the contiguous epitaxial material from the substrate.
3. The method of claim 1 , wherein the contiguous stiff support layer comprises a material selected from the group consisting of polymer, copolymer, oligomer, derivatives thereof, and combinations thereof.
4. The method of claim 1 , wherein the soft support layer comprises an elastomer, and the elastomer comprises rubber, foam, or derivatives thereof.
5. The method of claim 1 , wherein the soft support layer comprises a material selected from the group consisting of neoprene, latex, and derivatives thereof.
6. The method of claim 1 , wherein the handle plate comprises a material selected from the group consisting of plastic, polymer, oligomer, derivatives thereof, and combinations thereof.
7. The method of claim 1 , wherein the sacrificial layer is exposed to a wet etch solution during the etching process, the wet etch solution comprises hydrofluoric acid, a surfactant, and a buffer.
8. The method of claim 1 , wherein the sacrificial layer is exposed to a hydrogen fluoride vapor during the etching process.
9. The method of claim 1 , wherein the contiguous epitaxial material comprises a material selected from the group consisting of gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, and combinations thereof.
10. The method of claim 1 , wherein the contiguous epitaxial material comprises a cell structure comprising multiple layers, the cell structure comprises a material selected from the group consisting of gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, aluminum gallium arsenide, n-doped aluminum gallium arsenide, p-doped aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, and combinations thereof.
11. The method of claim 1 , wherein the sacrificial layer comprises a material selected from the group consisting of aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.