Epitaxial lift off stack having a universally shrunk handle and methods thereof
View Patent ↗Embodiments of the invention generally relate to epitaxial lift off (ELO) thin films and devices and methods used to form such films and devices. In one embodiment, a method for forming an ELO thin film is provided which includes depositing an epitaxial material over a sacrificial layer on a substrate, adhering a universally shrinkable support handle onto the epitaxial material, wherein the universally shrinkable support handle contains a shrinkable material, and shrinking the support handle to form tension in the support handle and compression in the epitaxial material during a shrinking process. The method further includes removing the sacrificial layer during an etching process, peeling the epitaxial material from the substrate while forming an etch crevice therebetween, and bending the support handle to have substantial curvature.
1. A thin film stack material for at least one of a solar device, a semiconductor device, and an electronic device, comprising:
a sacrificial layer disposed on a substrate;
an epitaxial material disposed over the sacrificial layer; and
a support handle disposed over the epitaxial material, wherein the support handle comprises a plurality of layers of shrinkable material, which upon being shrunk, form tension in the support handle and compression in the epitaxial material, and wherein at least two of the plurality of layers are different material.
2. The thin film stack material of claim 1 , wherein the shrinkable material comprises a material selected from the group consisting of plastic, polymer, oligomer, derivatives thereof, and combinations thereof.
3. The thin film stack material of claim 1 , wherein the support handle comprises a heat shrink polymer.
4. The thin film stack material of claim 1 , wherein an adhesive is between the support handle and the epitaxial material, and the adhesive is selected from the group consisting of pressure sensitive adhesive, hot melt adhesive, UV curing adhesive, natural adhesive, synthetic adhesive, derivatives thereof, and combinations thereof.
5. The thin film stack material of claim 1 , wherein the epitaxial material comprises at least one material selected from the group consisting of gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, and combinations thereof.
6. The thin film stack material of claim 1 , wherein the epitaxial material comprises a cell structure containing multiple layers comprising at least one 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.
7. The thin film stack material 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.
8. The thin film stack material of claim 1 , wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.