HK1155276A - Epitaxial lift off stacks and methods - Google Patents

Abstract

Embodiments of the invention generally relate to epitaxial lift off (ELO) thin films and devices and methods used to form such films and devices. The ELO thin films generally contain epitaxially grown layers which are formed on a sacrificial layer disposed on or over a substrate, such as a wafer. A support handle may be disposed on the opposite side of the epitaxial material than the substrate. The support handle may be used to stabilize the epitaxial material, such as by providing compression to the epitaxial material. Furthermore, the support handle may be used to grip and hold the epitaxial material during the etching and removal steps of the ELO process. In various embodiments, the support handle may include a pre-curved handle, a multi-layered handle, a non-uniform wax handle, and two shrinkage-induced handles which universally or unidirectional shrink to provide compression to the epitaxial material.

Description

Epitaxial migration stack and method

Background

Technical Field

Embodiments of the present invention relate generally to the fabrication of solar devices, semiconductor devices, and electronic devices, and more particularly, to Epitaxial Lift Off (ELO) devices and methods.

Description of the Related Art

One stage in device fabrication involves the handling and packaging of thin films for use as solar devices, semiconductor devices, or other electronic devices. Such thin film devices may be fabricated using a variety of processes for depositing and removing materials on a wafer or other substrate. One rare technique for fabricating thin film devices is known as the epitaxial migration (ELO) process. The ELO process includes depositing an epitaxial layer or film on a sacrificial layer on a growth substrate, followed by etching the sacrificial layer to separate the epitaxial layer from the growth substrate. The removed thin epitaxial layer is referred to as an ELO film or layer and generally includes a thin film used as a solar device, semiconductor device, or other electronic device.

For example, thin ELO films are very difficult to manage or handle when bonded to a substrate or when packaged because ELO films are very fragile and have narrow dimensions. ELO films crack under very little force. Furthermore, due to its extremely narrow dimensions, ELO films are very difficult to align.

The sacrificial layer is typically very thin and is typically etched away via a wet chemical process. The rate of the overall process may be limited by the lack of transport or exposure of reactants to the etch front, which results in less removal of byproducts from the etch front. This described process is a limited diffusion process and if the film maintains the deposited geometry, very narrow and long openings will form to severely limit the overall rate of the process. To reduce the transport limitations of the diffusion process, it may be advantageous to spread out the resulting gap created by the etched or removed sacrificial layer and bend the epitaxial layer away from the growth substrate. A crack is formed between the epitaxial layer and the growth substrate-its geometry provides greater transport of species towards and away from the etch front. The reactant moves toward the etch front while the by-products generally move away from the etch front.

However, the bending of the epitaxial layer may induce stress in its interior, and the amount of bending is limited by the film strength. Epitaxial layers typically comprise brittle materials that do not undergo plastic deformation prior to failure and therefore may suffer from crack-induced failure.

To minimize the possibility of crack propagation, the brittle epitaxial layer may be maintained under compressive stress. Cracks generally do not propagate through regions of residual compressive stress. Since the epitaxial layer is located outside the curvature of the crack, the epitaxial layer is placed under tensile stress when the epitaxial layer is bent away from the growth substrate. Tensile stress limits the amount of crack curvature and reduces the rate of the etching process. To overcome this limitation, the residual compressive stress may be implanted within the epitaxial layer prior to etching the sacrificial layer. This initial compressive stress may be offset by the tensile stress caused by bending and thus allow a greater amount of bending during the separation process.

Therefore, there is a need for a more robust ELO film and method of forming, removing, and processing the ELO film.

Summary of The Invention

Embodiments of the present invention generally relate to epitaxial transport (ELO) films and devices, and methods for forming such films and devices. ELO films typically include an epitaxially grown layer formed on a sacrificial layer disposed on or over a substrate, such as a wafer. The support material or support handle may be disposed on opposite sides of the epitaxial material except the substrate. The support handle may be used to stabilize the epitaxial material, for example, by providing compression of the epitaxial material. Furthermore, the support handle may be used to grip and support the epitaxial material during the etching and removal steps of the ELO process. In various embodiments, the support material or support handle may comprise a pre-bent handle, a multi-layer handle, a non-uniform wax handle, and two shrinkage-induced handles (shrinkage-induced handles) that generally or unidirectionally shrink to provide compression to the epitaxial material.

In one embodiment, a method for forming a thin film material during an ELO process is provided that includes forming an epitaxial material on or over a sacrificial layer, the sacrificial layer disposed on or over a substrate; bonding the multilayer support handle onto the epitaxial material; removing the sacrificial layer during the etching process; and stripping the epitaxial material from the substrate during the etching process while forming an etch crack therebetween while maintaining compression in the epitaxial material. The method further provides that the multi-layered support handle comprises: a hard support layer disposed on or over or bonded to the epitaxial material; a soft support layer bonded to the hard support layer; and a handle plate bonded to the flexible support layer.

In one example, a multi-layered support handle comprises: a hard support layer disposed over the epitaxial material; a soft support layer disposed above the hard support layer; and a handle plate arranged above the flexible supporting layer. The multilayer support handle is disposed over and maintains compression of the epitaxial material. In some embodiments, the rigid support layer may comprise a polymer, copolymer, oligomer, derivatives thereof, or combinations thereof. In one example, the stiff support layer comprises a copolymer, for example, an ethylene/vinyl acetate (EVA) copolymer or a derivative thereof. In other examples, the stiff support layer may comprise a hot melt adhesive, an organic material or organic coating, an inorganic material, or a combination thereof. In one example, the inorganic material comprises a plurality of inorganic layers, for example, metal layers and/or dielectric layers. In another example, the stiff support layer may comprise a composite or patterned composite, such as an organic/inorganic material. The composite material may comprise at least one organic material and at least one inorganic material. In some examples, the inorganic material may comprise a metal layer, a dielectric layer, or a combination thereof. In another example, the stiff support layer may comprise a wax or derivative thereof, such as a black wax.

In other embodiments, the soft support layer may comprise an elastomer, such as rubber, foam, or derivatives thereof. Alternatively, the flexible support layer may comprise a material such as neoprene, latex, or a derivative thereof. The soft support layer may comprise a monomer. For example, the soft support layer may comprise ethylene propylene diene monomer or derivatives thereof. In another embodiment, the soft support layer may comprise a liquid or fluid contained within the membrane. Optionally, the soft support layer may comprise a gas, which is contained within the membrane. The membrane may comprise a material such as rubber, foam, neoprene, latex, or a derivative thereof. In one example, the membrane is a balloon, such as a rubber balloon or a latex balloon.

In another embodiment, the handle plate may be made of or comprise a plastic material, a polymeric material, or an oligomeric material, derivatives thereof, mixtures thereof, or combinations thereof. In one example, the handle plate may comprise polyester or derivatives thereof. The shank plate may have a thickness in a range from about 50.8 μm to about 127.0 μm, for example, about 23.4 μm.

In one embodiment, the method further includes removing the epitaxial material from the substrate and attaching a support substrate to an exposed surface of the epitaxial material. The support substrate may be bonded to the exposed surface of the epitaxial material with an adhesive, thereby forming an adhesive layer therebetween. In one example, the adhesive is an optical adhesive and/or may be uv curable (e.g., cured by uv exposure). In some examples, the binder may comprise a mercapto ester compound. In other examples, the adhesive may further comprise a material, such as butyl octyl phthalate, tetrahydrofurfuryl methacrylate, acrylate monomers, derivatives thereof, or combinations thereof.

In another embodiment, a thin film material, such as an ELO thin film stack, is provided comprising: a support substrate disposed on or over a first surface of the epitaxial material; and a support handle disposed on or above the other surface of the epitaxial material. An adhesion layer may be disposed between the epitaxial material and the support substrate. In one example, the support handle may be a multi-layer support handle comprising: a hard support layer disposed on or over the epitaxial material; a soft support layer disposed on or above the hard support layer; and a handle plate disposed on or above the flexible support layer.

In another embodiment, an ELO thin film stack is provided, comprising: a sacrificial layer disposed over the substrate; an epitaxial material disposed on or over the sacrificial layer; and a flattened, pre-curved support material or handle disposed on or over the epitaxial material. The flattened, pre-bent support handle is under tension when the epitaxial material is under compression. The flattened, pre-curved support handle may comprise a single layer or multiple layers. The flattened pre-curved support handle may comprise wax, polyethylene, polyester, polyolefin, polyethylene terephthalate polyester, rubber, derivatives thereof, or combinations thereof. In some examples, the flattened pre-curved support handle comprises wax. In other examples, the flattened, pre-curved support handle comprises polyethylene terephthalate polyester or a derivative thereof. In other examples, the flattened, pre-curved support handle comprises a polyolefin or derivative thereof.

In some embodiments, the flattened, pre-curved support handle comprises a first layer having a wax; and a second layer having a polymer and disposed over the first layer. For example, the second layer may comprise polyethylene terephthalate polyester or derivatives thereof. In other examples, the flattened, pre-curved support handle comprises at least three layers. The third layer may comprise wax and be disposed on or over the second layer. In some examples, the third layer comprises another polymer (e.g., polyethylene or a derivative thereof) and is disposed on or over the second layer. In other embodiments, an adhesive is disposed between the flattened, pre-curved support handle and the epitaxial material.

In other embodiments, methods are provided for forming a thin film material, such as an ELO thin film stack, during an ELO process, which include forming an epitaxial material on or over a sacrificial layer on a substrate; bonding the flattened pre-curved support material or stem onto or over the epitaxial material; removing the sacrificial layer during the etching process; and stripping the epitaxial material from the substrate while forming an etch crack therebetween; and bending the flattened pre-curved support shank to have a substantial curvature. The flattened support handle is under tension so that the epitaxial material is under compression. The flattened support handle may be formed by flattening a curved support material.

In another embodiment, an ELO thin film stack is provided, comprising: a sacrificial layer disposed on or over the substrate; an epitaxial material disposed on or over the sacrificial layer; and a generally collapsible support handle disposed on or above the epitaxial material, wherein the support handle comprises a generally collapsible material that, upon collapse, creates tension in the support handle and compression in the epitaxial material. In one example, the common shrinkable material comprises an amorphous material. During the ordinary shrinking process, the amorphous material may crystallize to undergo a net volume reduction. Common shrinkable materials may comprise plastics, polymers, oligomers, derivatives thereof, mixtures thereof, or combinations thereof. In some examples, the common collapsible support handle comprises a heat shrink polymer.

In another embodiment, a method for forming an ELO thin film stack during an ELO process is provided that includes forming an epitaxial material on or over a sacrificial layer, the sacrificial layer disposed on or over a substrate; bonding a common shrinkable support handle to or over the epitaxial material, wherein the support handle comprises a common shrinkable material; shrinking the support handle during a normal shrinking process to create tension in the support handle and compression in the epitaxial material; removing the sacrificial layer during the etching process; and stripping the epitaxial material from the substrate while forming an etch crack therebetween; and bending the support handle to have a substantial curvature. A common collapsible support handle may comprise one or more layers.

In another embodiment, a thin film stack material is provided, comprising: a sacrificial layer disposed on or over the substrate; an epitaxial material disposed on or over the sacrificial layer; and a one-way retractable support handle disposed on or above the epitaxial material. The unidirectional retractable support stalk may comprise a retractable material and reinforcing fibers extending unidirectionally through the retractable material. The shrinkable material shrinks unidirectionally and tangentially to the reinforcing fibers to create tension in the support handle and compression in the epitaxial material.

The reinforcing fibers are high strength polymer fibers. In one example, the reinforcing fibers comprise polyethylene or a derivative thereof. In some examples, the reinforcing fibers comprise a negative coefficient of linear thermal expansion along the length of the fiber. Generally, the reinforcing fibers have a tensile modulus in the range of from about 15GPa to about 134 GPa.

In other embodiments, methods are provided for forming a thin film material during an ELO process, including forming an epitaxial material on or over a sacrificial layer on a substrate; bonding a unidirectional shrinkable support handle to the epitaxial material, wherein the support handle comprises a shrinkable material and reinforcing fibers extending unidirectionally through the shrinkable material; and shrinking the support handle tangent to the reinforcing fiber during the unidirectional shrinkage process to create tension in the support handle and compression in the epitaxial material. The method further includes removing the sacrificial layer during the etching process; stripping the epitaxial material from the substrate while forming an etch crack therebetween; and bending the support handle to have a substantial curvature.

In other embodiments, a thin film stack material is provided comprising: a sacrificial layer disposed on or over the substrate; an epitaxial material disposed on or over the sacrificial layer; and a non-uniform support handle disposed on or over the epitaxial material, wherein the non-uniform support handle comprises a wax film having a varying thickness.

In another embodiment, a method for forming a thin film material during an ELO process is provided that includes forming an epitaxial material disposed on or over a sacrificial layer on a substrate; and bonding a non-uniform support handle onto or over the epitaxial material, wherein the non-uniform support handle comprises a wax film having a varying thickness. The method further includes removing the sacrificial layer during the etching process; stripping the epitaxial material from the substrate while forming an etch crack therebetween; and bending the non-uniform support handle during the etching process to form a compression in the epitaxial material.

Brief Description of Drawings

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

FIG. 1 illustrates an ELO thin film stack on a wafer according to embodiments described herein;

FIG. 2A shows a pre-curved support handle according to embodiments described herein;

FIGS. 2B through 2C illustrate an ELO thin film stack including a pre-curved support handle according to embodiments described herein;

fig. 2D shows the pre-bent support handle and epitaxial material after being removed from the wafer as described in embodiments herein;

FIGS. 3A through 3C illustrate an ELO thin film stack including a common collapsible support handle according to another embodiment described herein;

FIG. 3D shows a generic collapsible support handle and epitaxial material after being removed from the wafer as described in embodiments herein;

FIGS. 4A through 4C illustrate an ELO film stack containing a one-way retractable support handle according to other embodiments described herein;

fig. 4D shows the unidirectional shrinkable handle and epitaxial material after being removed from the wafer as described in embodiments herein;

figures 5A-5B illustrate a non-uniform wax support handle disposed on or over a thin film stack according to other embodiments described herein;

FIG. 6A shows a multilayer support handle disposed over a thin film stack on a substrate according to another embodiment described herein; and

figure 6B illustrates a multi-layer support handle and a thin film stack disposed on a support substrate according to another embodiment described herein.

Detailed description of the invention

Fig. 1 illustrates a substrate 100 comprising an ELO thin film stack 150 disposed on a wafer 102, as described in one embodiment herein. The ELO thin film stack 150 may have: a sacrificial layer 104 disposed on or over the wafer 102; an epitaxial material 106 disposed on or over sacrificial layer 104; and a support handle 108 disposed on or over the epitaxial material 106. In various embodiments, the support handle 108 is under tension while the epitaxial material 106 is under compression. The ELO process includes removing the sacrificial layer 104 during the etching process while simultaneously peeling the epitaxial material 106 from the wafer 102 and forming an etch crack therebetween until the epitaxial material 106 and the support handle 108 are removed from the wafer 102. Sacrificial layer 104 typically comprises aluminum arsenide.

The wafer 102 may comprise or be made of various materials, such as group III/V materials, and may be doped with other elements. In one embodiment, wafer 106 comprises gallium arsenide or derivatives thereof. The GaAs wafer has a thickness of about 5.73 × 10^-6℃^-1The coefficient of thermal expansion of (a). In various embodiments, the support handle 108 comprises a material (e.g., a wax or polymer) having a relatively high coefficient of thermal expansion.

The support handle 108 may be a single layer of material or multiple layers. In various embodiments, support handle 108 can be a flattened, pre-bent support handle formed by flattening a bent support material. In another implementation, the support handle 108 may comprise a shrinkable material, such as a shrink wrap. In an alternative embodiment, the support handle 108 may comprise a shrinkable material having reinforcing fibers extending unidirectionally through the shrinkable material. In another embodiment, the support handle 108 may comprise a wax film having a thickness that varies or is non-uniform across the substrate 100. In another embodiment, the support handle 108 may be a multi-layer handle.

Pre-bent handle

Fig. 2A-2D illustrate a pre-curved support material or handle during various aspects of an ELO process or inside an ELO thin film stack as described in one embodiment herein. Fig. 2A shows a pre-bent support material, such as a pre-bent support handle 202. The pre-curved support handle 202 includes a top surface 211 and a bottom surface 213. In one embodiment, the pre-bent support handle 202 may be flattened or straightened prior to bonding or attachment to the substrate 200, such as the epitaxial material 204. Alternatively, the pre-bent support handle 202 may be flattened or straightened while being bonded or attached to the base 200. Once flattened or straightened, the pre-bent support handle 202 is subjected to tension, which serves to create compression of the underlying layer (e.g., epitaxial material 204) when bonded or attached to the substrate 200.

Fig. 2B illustrates a substrate 200 comprising an ELO thin film stack 250 disposed on or over a wafer 208, as described in one embodiment herein. The ELO thin film stack 250 may have: a sacrificial layer 206 disposed on or over a wafer 208; an epitaxial material 204 disposed on or over the sacrificial layer 206; and a pre-curved support handle 202 disposed on or over the epitaxial material 204. During the etching process, the flattened pre-curved support handle 202 is curved toward the top surface 211, as shown in fig. 2C. The pre-curved support handle 202 may have a radius of curvature in a range from about 10cm to about 100 cm.

In some embodiments, the pre-bent support handle 202 comprises multiple layers, for example, a first wax layer and a second polymer layer disposed on or over the first layer. For example, the second layer may comprise a polyethylene terephthalate polyester, such asA polymer film. In other examples, the pre-curved support handle 202 includes at least three layers. The third layer may be disposed on or over the second layer. In some examples, the third layer comprises another polymer (e.g., polyethylene or derivatives thereof) or wax disposed on or over the second layer.

Fig. 2B shows a substrate 200 containing a pre-curved support handle 202 after flattening. The flattened, pre-curved support handle 202 may be disposed on or over the epitaxial material 204, and the epitaxial material 204 may be disposed on or over the sacrificial layer 206. Sacrificial layer 206 may be disposed on or over wafer 208.

In some embodiments, an adhesive (not shown) may be disposed between the pre-bent support handle 202 and the epitaxial material 204. The adhesive may be a pressure sensitive adhesive, a hot melt adhesive, an Ultraviolet (UV) curable adhesive, a natural adhesive, a synthetic adhesive, derivatives thereof, or combinations thereof.

In some embodiments, the sacrificial layer 206 may comprise aluminum arsenide, alloys thereof, derivatives thereof, or combinations thereof. In one example, the sacrificial layer 206 comprises an aluminum arsenide layer. The sacrificial layer 206 may have a thickness of about 20nm or less, preferably a thickness in the range from about 1nm to about 10nm, and more preferably a thickness from about 4nm to about 6 nm. Wafer 208 may be a wafer or substrate and typically comprises gallium arsenide, gallium arsenide alloys, or other derivatives, and may be n-doped or p-doped. In one example, wafer 208 comprises an n-doped gallium arsenide material. In another example, wafer 208 includes a p-doped gallium arsenide material.

In some implementations, the epitaxial material 204 may include gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, or combinations thereof. Epitaxial material 204 may comprise one layer, but typically comprises multiple layers. In some examples, the epitaxial material 204 includes one layer having gallium arsenide and another layer having aluminum gallium arsenide. In another example, the epitaxial material 204 includes a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

The gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 300 nm; the aluminum gallium arsenide passivation layer may have a thickness in a range from about 10nm to about 50nm, e.g., about 30 nm; and the gallium arsenide active layer may have a thickness in a range from about 500nm to about 2000nm, for example, about 1000 nm. In some examples, the epitaxial material 204 further comprises a second aluminum gallium arsenide passivation layer. The second gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 300 nm.

In other embodiments herein, the epitaxial material 204 may have a unit cell structure, which includes multiple layers. The cell structure may comprise 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, or combinations thereof.

As described in embodiments herein, fig. 2C illustrates that during the ELO etching process, an etch crack 210 is formed while the sacrificial layer 206 is etched away and the pre-curved support handle 202 and epitaxial material are stripped from the wafer 208. Fig. 2D shows the pre-bent support handle 202 and epitaxial material 204 after removal from the wafer 208. The flattened, pre-curved support handle 202 is under tension while the epitaxial material 204 is under compression.

In one embodiment of a method for forming a thin film material, the sacrificial layer 206 may be disposed on or over a substrate 200, such as a wafer 208; epitaxial material 204 is disposed on or over sacrificial layer 206; and a flattened, pre-curved support material or handle may be disposed on or over the epitaxial material 204. The flattened, pre-curved support material or handle may comprise a single layer or multiple layers. The flattened, pre-curved support material or handle may comprise wax, polyethylene, polyester, polyolefin, polyethylene terephthalate polyester, rubber, derivatives thereof, or combinations thereof. In some examples, the flattened pre-curved support handle 202 comprises wax. In other examples, the flattened, pre-curved support handle 202 comprises polyethylene terephthalate polyester or a derivative thereof, for exampleAnd (3) a membrane. In other examples, the pre-curved support handle 202 comprises a polyolefin or derivative thereof.

In another embodiment, a method for forming a thin film material during an ELO process is provided that includes forming an epitaxial material 204 on or over a sacrificial layer 206 disposed on a substrate 200, such as a wafer 208. The method further provides: bonding or attaching a flattened, pre-curved support material, such as the pre-curved support handle 202, onto or over the epitaxial material 204, wherein the flattened, pre-curved support handle 202 is formed by flattening the curved support material, and the flattened, pre-curved support handle 202 is under tension while the epitaxial material 204 is under compression; removing the sacrificial layer 206 during the etching process; and stripping the epitaxial material 204 from the substrate while forming an etch crack therebetween; and bending the flattened, pre-curved support handle 202 to have a substantial curvature.

In some implementations, the sacrificial layer 206 may be exposed to a wet etch solution during the ELO etch process. In some examples, the wet etching solution includes hydrofluoric acid, and may include a surfactant and/or a buffer. The sacrificial layer 206 may be etched at a rate of about 0.3 mm/hr or greater, preferably about 1 mm/hr or greater, and more preferably about 5 mm/hr or greater.

In an alternative embodiment, the sacrificial layer 206 may be exposed to an electrochemical etch during the ELO etch process. The electrochemical etching may be a biased process or a plating process. Likewise, in another embodiment described herein, the sacrificial layer 206 may be exposed to a vapor phase etch during the ELO etch process. The vapor phase etching includes exposing the sacrificial layer 206 to hydrogen fluoride vapor. The ELO etch process may be a photochemical etch, a thermally enhanced etch, a plasma enhanced etch, a stress enhanced etch, derivatives thereof, or combinations thereof.

Induced shrinkage handle (common shrinkage)

Fig. 3A-3D illustrate a common shrinkable support material or handle during different aspects of an ELO process or inside an ELO thin film stack as described in some embodiments herein. Fig. 3A illustrates a substrate 300 comprising an ELO thin film stack 350 disposed on or over a wafer 308, as described in one embodiment herein. The ELO thin film stack 350 may include: a sacrificial layer 306 disposed on or over a wafer 308; an epitaxial material 304 disposed on or over a sacrificial layer 306; and a common collapsible support handle 302 disposed on or above the epitaxial material 304. Fig. 3B illustrates that the force/stress 320, when applied to the common collapsible support handle 302, provides a common collapse 322 across the plane of the substrate 300.

The collapsible support handle 302 comprises a generally collapsible material such as wax, polyethylene, polyester, polyolefin, polyethylene terephthalate polyester, rubber, and the likeDerivatives or combinations thereof. In one example, the collapsible support handle 302 includes wax. In some examples, the collapsible support handle 302 comprises polyethylene terephthalate polyester or derivatives thereof, e.g.And (3) a membrane. In other examples, the collapsible support handle 302 comprises a polyolefin or a derivative thereof. In other examples, the collapsible support handle 302 includes: a first layer having a wax; and a second layer having a polymer (e.g., polyethylene terephthalate polyester) and disposed over the first layer.

The common collapsible support handle 302 may comprise three or more layers. For example, the collapsible support handle 302 may also have a third layer comprising a wax or polymer and disposed over the second layer. The third layer may comprise polyethylene or a derivative thereof.

The collapsible support handle 302 includes a bottom surface and a top surface, and the bottom surface is bonded to the epitaxial material 304 or positioned over the epitaxial material 304. During the etching process, the collapsible support handle 302 flexes toward the top surface. In another embodiment, the normally shrinkable material comprises an amorphous material, and during the shrinking process, the amorphous material may crystallize to undergo a net volume reduction. A common shrinkable material may comprise at least one plastic, rubber, polymer, oligomer, derivative thereof, or combination thereof. In one particular example, a common shrinkable material comprises polyester or derivatives thereof. In other examples, a heat shrinkable adhesive tape may be used as the common shrinkable support handle 302.

In other embodiments, the collapsible support handle 302 may be heated during the collapsing process. The collapsible support handle 302 may comprise a heat shrink or a polymer. Alternatively, the collapsible support handle 302 may be collapsed by removing the solvent from the collapsible material. The collapsible support handle 302 may be bent to have a radius of curvature in a range from about 10cm to about 100 cm.

In some embodiments, an adhesive (not shown) may be disposed between the common collapsible support handle 302 and the epitaxial material 304. The adhesive may be a pressure sensitive adhesive, a hot melt adhesive, an Ultraviolet (UV) curable adhesive, a natural adhesive, a synthetic adhesive, derivatives thereof, or combinations thereof. In some examples, a heat shrink tape including an adhesive on one side may be used as the collapsible support handle 302.

In some implementations, the epitaxial material 304 may include gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, or combinations thereof. Epitaxial material 304 may comprise one layer, but typically comprises multiple layers. In some examples, epitaxial material 304 includes a layer having gallium arsenide; and another layer with aluminum gallium arsenide. In another example, the epitaxial material 304 includes a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

The gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 300 nm; the aluminum gallium arsenide passivation layer may have a thickness in a range from about 10nm to about 50nm, e.g., about 30 nm; and the gallium arsenide active layer may have a thickness in a range from about 500nm to about 2000nm, for example, about 1000 nm. In some examples, the epitaxial material 304 further comprises a second aluminum gallium arsenide passivation layer. The second gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 300 nm.

In other embodiments herein, epitaxial material 304 may have a unit cell structure, which includes multiple layers. The cell structure may comprise 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, or combinations thereof.

In another embodiment, the sacrificial layer 306 may comprise aluminum arsenide, alloys thereof, derivatives thereof, or combinations thereof. In one example, the sacrificial layer 306 comprises an aluminum arsenide layer. The sacrificial layer 306 may have a thickness of about 20nm or less, preferably a thickness in the range from about 1nm to about 10nm, more preferably a thickness from about 4nm to about 6 nm. The wafer 308 may be a wafer or substrate and typically comprises gallium arsenide, gallium arsenide alloys, or other derivatives, and may be n-doped or p-doped. In one example, wafer 308 comprises an n-doped gallium arsenide material. In another example, wafer 308 comprises a p-doped gallium arsenide material.

Fig. 3C illustrates the formation of an etch crack 310 while the sacrificial layer 306 is etched away and the collapsible mandrel 302 and epitaxial material 304 are stripped from the wafer 308. Fig. 3D shows the collapsible support handle 302 and epitaxial material 304 after removal from the wafer 308.

In one embodiment of a method for forming a thin film material during an ELO process, the epitaxial material 304 may be formed or deposited over a sacrificial layer 306, the sacrificial layer 306 being disposed on or over a substrate 300, such as a wafer 308; and bonding the collapsible support handle 302 to or over the epitaxial material 304. The collapsible support handle 302 comprises a generally collapsible material. The method further provides: shrinking or reducing the size of the collapsible support handle 302 during the shrinking process to create tension in the collapsible support handle 302 and compression in the epitaxial material 304; the sacrificial layer 306 is removed during the etching process; and stripping the epitaxial material 304 from the substrate while forming etch cracks 310 therebetween; and the collapsible support handle 302 is bent to have a substantial curvature. The collapsible support handle 302 may comprise one or more layers.

In another embodiment, a method for forming a thin film material during an ELO process is provided, comprising: positioning a substrate 300 comprising an epitaxial material 304 disposed on or over a sacrificial layer 306, the sacrificial layer 306 disposed on or over a wafer 308; and bonding the collapsible support handle 302 to the epitaxial material 304. The collapsible support handle 302 comprises a generally collapsible material. The method further provides for shrinking or reducing the size of the collapsible support handle 302 during the shrinking process to create tension in the collapsible support handle 302 and compression in the epitaxial material 304; and removing the sacrificial layer 306 during the etching process. The method further provides for: the etching process further includes: stripping the epitaxial material 304 from the substrate; forming an etch crack 310 between the epitaxial material 304 and the substrate; and the collapsible support handle 302 is bent to have a substantial curvature.

In other embodiments, a thin film stack material is provided comprising: a sacrificial layer 306 disposed over the substrate; an epitaxial material 304 disposed over a sacrificial layer 306; and a collapsible support handle 302 disposed over the epitaxial material 304. The collapsible support handle 302 comprises a generally collapsible material that, when collapsed, creates tension in the collapsible support handle 302 and compression in the epitaxial material 304. In one example, the shrinkable material comprises an amorphous material. During the shrinking process, the amorphous material may crystallize to undergo a net volume reduction. The shrinkable material may comprise at least one plastic, polymer, oligomer, derivative thereof, or combination thereof. In some examples, the collapsible support handle 302 includes a heat shrink plastic or polymer.

In some implementations, the sacrificial layer 306 may be exposed to a wet etch solution during the etching process. The wet etch solution comprises hydrofluoric acid and may include a surfactant and/or a buffer. In some examples, the sacrificial layer 306 may be etched at a rate of about 0.3 mm/hr or greater, preferably about 1 mm/hr or greater, and more preferably about 5 mm/hr or greater.

In an alternative embodiment, the sacrificial layer 306 may be exposed to an electrochemical etch during the etching process. The electrochemical etch may be a bias process or a plating process. Likewise, in another embodiment described herein, the sacrificial layer 306 may be exposed to a vapor phase etch during the etching process. The vapor phase etching includes exposing the sacrificial layer 306 to hydrogen fluoride vapor. The etching process may be photochemical etching, thermally enhanced etching, plasma enhanced etching, stress enhanced etching, derivatives thereof, or combinations thereof.

Induced shrinkage handle (unidirectional shrinkage)

Fig. 4A through 4D illustrate a one-way shrinkable support material or handle during various aspects of an ELO process or inside an ELO thin film stack as described in one embodiment herein. Fig. 4A illustrates a substrate 400 comprising an ELO thin film stack 450 disposed on or over a wafer 408, as described in one embodiment herein. The ELO thin film stack 450 may have a sacrificial layer 406 disposed on or over the wafer 408; an epitaxial material 404 disposed on or over the sacrificial layer 406; and a one-way retractable support handle 402 disposed on or over epitaxial material 404.

One-way collapsible support handle 402 includes collapsible material and reinforcing fibers that extend unidirectionally through the collapsible material that collapse tangential to the reinforcing fibers upon collapse to create tension in collapsible support handle 402 and compression in epitaxial material 404. Fig. 4B illustrates that the force/stress 420 provides a unidirectional contraction 422 across the plane of the substrate 400 when applied to the collapsible support handle 402.

The collapsible support handle 402 includes a bottom surface and a top surface, and the bottom surface is bonded to the epitaxial material 404 or positioned over the epitaxial material 404. During the etching process, the collapsible support handle 402 may flex toward the top surface. In one example, the one-way shrinkable material comprises an amorphous material that can crystallize to undergo a net volume reduction during the one-way shrinking process. In another example, the one-way shrinkable material may comprise a plastic, a polymer, an oligomer, derivatives thereof, or combinations thereof. In one example, the one-way shrinkable material comprises polyester or derivatives thereof.

The reinforcing fibers may be high strength polymer fibers. The reinforcing fibers may comprise polyethylene or derivatives thereof. In some examples, the reinforcing fibers comprise a negative coefficient of linear thermal expansion along the length of the fiber. Generally, the reinforcing fibers have a tensile modulus in the range of from about 15GPa to about 134 GPa.

In some examples, the one-way collapsible support handle 402 may be heated during the collapsing process. The collapsible support handle 402 may comprise a heat shrinkable polymer and high strength polymer fibers. In other examples, the collapsible support handle 402 is collapsed by removing solvent from the collapsible material. The collapsible support handle 402 may be curved to have a radius of curvature in a range from about 10cm to about 100 cm.

In some embodiments, an adhesive (not shown) may be disposed between the one-way collapsible support handle 402 and the epitaxial material 404. The adhesive may be a pressure sensitive adhesive, a hot melt adhesive, an Ultraviolet (UV) curable adhesive, a natural adhesive, a synthetic adhesive, derivatives thereof, or combinations thereof.

In some implementations herein, the epitaxial material 404 may include gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, or combinations thereof. Epitaxial material 404 may comprise one layer, but typically comprises multiple layers. In some examples, the epitaxial material 404 includes one layer having gallium arsenide and another layer having aluminum gallium arsenide. In another example, the epitaxial material 404 includes a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

The gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 400 nm; the aluminum gallium arsenide passivation layer may have a thickness in a range from about 10nm to about 50nm, e.g., about 30 nm; and the gallium arsenide active layer may have a thickness in a range from about 500nm to about 2000nm, for example, about 1000 nm. In some examples, the epitaxial material 404 further includes a second aluminum gallium arsenide passivation layer. The second gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 400 nm.

In other embodiments herein, the epitaxial material 404 may have a unit cell structure, which includes multiple layers. The cell structure may comprise 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, or combinations thereof.

In another embodiment, the sacrificial layer 406 may comprise aluminum arsenide, alloys thereof, derivatives thereof, or combinations thereof. In one example, the sacrificial layer 406 comprises an aluminum arsenide layer. The sacrificial layer 406 may have a thickness of about 20nm or less, preferably a thickness in the range from about 1nm to about 10nm, and more preferably a thickness from about 4nm to about 6 nm. Wafer 408 can be a wafer or substrate and typically comprises gallium arsenide, gallium arsenide alloys, or other derivatives, and can be n-doped or p-doped. In one example, wafer 408 comprises an n-doped gallium arsenide material. In another example, wafer 408 comprises a p-doped gallium arsenide material.

Fig. 4C illustrates the formation of an etch crack 410 while the sacrificial layer 406 is etched away and the collapsible handle 402 and epitaxial material 404 are stripped from the wafer 408. Fig. 4D shows the collapsible support handle 402 and epitaxial material 404 after removal from the wafer 408.

In another embodiment, a method for forming a thin film material during an ELO process is provided, comprising: forming an epitaxial material 404 over a sacrificial layer 406 on a substrate 400; bonding a collapsible support handle 402 to the epitaxial material 404, wherein the collapsible support handle 402 comprises a unidirectional collapsible material and reinforcing fibers extending unidirectionally through the collapsible material; and shrinking or reducing the collapsible support handle 402 tangent to the reinforcing fibers during the shrinking process to create tension in the collapsible support handle 402 and compression in the epitaxial material 404. The method further comprises the following steps: removing the sacrificial layer 406 during the etching process; stripping the epitaxial material 404 from the substrate while forming etch cracks therebetween; and bending the one-way retractable support handle 402 to have a substantial curvature.

In one embodiment, a method for forming a thin film material during an ELO process is provided, comprising: depositing an epitaxial material 404 on or over a sacrificial layer 406, the sacrificial layer 406 disposed over a wafer 408 of a substrate 400; and bonding the collapsible support handle 402 to the epitaxial material 404. The collapsible support handle 402 comprises a unidirectional collapsible material and reinforcing fibers extending unidirectionally through the collapsible material. The method further provides: shrinking or reducing the collapsible support handle 402 tangent to the reinforcing fibers during the shrinking process to create tension in the collapsible support handle 402 and compression in the epitaxial material 404; and the sacrificial layer 406 is removed during the etching process. The etching process comprises the following steps: stripping the epitaxial material from the substrate 404; forming an etch crack between the epitaxial material 404 and the substrate; and bending the one-way retractable support handle 402 to have a substantial curvature.

In some implementations, the sacrificial layer 406 may be exposed to a wet etch solution during the etching process. The wet etch solution comprises hydrofluoric acid and may include a surfactant and/or a buffer. In some examples, the sacrificial layer 406 may be etched at a rate of about 0.3 mm/hr or greater, preferably about 1 mm/hr or greater, and more preferably about 5 mm/hr or greater.

In an alternative embodiment, the sacrificial layer 406 may be exposed to an electrochemical etch during the etching process. The electrochemical etch may be a bias process or a plating process. Likewise, in another embodiment described herein, the sacrificial layer 406 may be exposed to a vapor phase etch during the etching process. The vapor phase etch includes exposing the sacrificial layer 406 to hydrogen fluoride vapor. The etching process may be photochemical etching, thermally enhanced etching, plasma enhanced etching, stress enhanced etching, derivatives thereof, or combinations thereof.

Non-uniform wax handle

Fig. 5A-5B illustrate a substrate 500 comprising an ELO thin film stack 550 disposed on or over a wafer 508, as described in one embodiment herein. The ELO thin film stack 550 may have: a sacrificial layer 506 disposed on or over a wafer 508; epitaxial material 504 disposed on or over sacrificial layer 506; and a non-uniform support handle 502 disposed on or over the epitaxial material 504. In one embodiment, the non-uniform support handle 502 comprises a wax film having a varying thickness, as described in some embodiments herein. In one example, the varying thickness of the non-uniform support handle 502 is thickest in or near the center 510a of the non-uniform support handle 502, as shown in FIG. 5A. In another example, the varying thickness of the non-uniform support handle 502 is thinnest in or near the center 510B of the non-uniform support handle 502, as shown in FIG. 5B.

In another embodiment, the ELO thin film stack 550 includes: a sacrificial layer 506 disposed over the substrate; an epitaxial material 504 disposed over a sacrificial layer 506; and a non-uniform support handle 502 disposed over the epitaxial material 504, wherein the non-uniform support handle 502 comprises a wax film having a varying thickness or a non-uniform thickness.

In other embodiments, methods are provided for forming a thin film material during an ELO process, comprising: forming an epitaxial material 504 over a sacrificial layer 506 on a substrate; bonding a non-uniform support handle 502 to the epitaxial material 504, wherein the non-uniform support handle 502 comprises a wax film having a varying thickness; removing the sacrificial layer 506 during the etching process; and stripping the epitaxial material 504 from the substrate while forming an etch crack therebetween; and bending the non-uniform support handle 502 during the etching process to create compression in the epitaxial material 504.

In another embodiment, a method for forming a thin film material during an ELO process is provided, comprising: positioning a substrate comprising epitaxial material 504 disposed over a sacrificial layer 506 on the substrate; bonding a non-uniform support handle 502 to the epitaxial material 504, wherein the non-uniform support handle 502 comprises a wax film having a varying thickness; and removing the sacrificial layer 506 during an etching process, wherein the etching process further comprises stripping the epitaxial material 504 from the substrate; forming an etch crack between the epitaxial material 504 and the substrate; and bending the non-uniform support handle 502 during the etching process to create compression in the epitaxial material 504.

In some embodiments, the non-uniform support handle 502 comprises a bottom surface of a wax film and a top surface of a flexible member, and the bottom surface is bonded to the epitaxial material 504. The non-uniform support handle 502 may be curved toward the top surface. The non-uniform support handle 502 can be bent to have a radius of curvature in a range from about 10cm to about 100 cm. The flexible member may comprise a plastic, a polymer, an oligomer, derivatives thereof, or combinations thereof, for example, a polyester or polyester derivative. The flexible member may have a film thickness in the range from about 50.8 μm (about 20 gauge) to about 127.0 μm (about 500 gauge), preferably about 23.4 μm (about 92 gauge).

In other examples, the wax film comprises a wax having a softening point temperature in the range of from about 65 ℃ to about 95 ℃, preferably a temperature of from about 80 ℃ to about 90 ℃, for example about 85 ℃. In one example, the varying thickness of the wax film is thickest in or near the center of the wax film (fig. 5A), or thinnest in or near the center of the wax film (fig. 5B). In various embodiments, the varying thickness of the wax film may range from about 1 μm to about 100 μm. In one embodiment, the wax film has a thinnest section having a thickness in a range from about 1 μm to about 25 μm, and has a thickest section having a thickness in a range from about 25 μm to about 100 μm.

In some implementations herein, the epitaxial material 504 may include gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, or combinations thereof. Epitaxial material 504 may comprise one layer, but typically comprises multiple layers. In some examples, the epitaxial material 504 includes one layer having gallium arsenide and another layer having aluminum gallium arsenide. In another example, the epitaxial material 504 includes a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

The gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 500 nm; the aluminum gallium arsenide passivation layer may have a thickness in a range from about 10nm to about 50nm, e.g., about 30 nm; and the gallium arsenide active layer may have a thickness in a range from about 500nm to about 2000nm, for example, about 1000 nm. In some examples, the epitaxial material 504 further includes a second aluminum gallium arsenide passivation layer. The second gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 500 nm.

In other embodiments herein, epitaxial material 504 may have a unit cell structure, which includes multiple layers. The cell structure may comprise 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, or combinations thereof.

In another embodiment, the sacrificial layer 506 may comprise aluminum arsenide, alloys thereof, derivatives thereof, or combinations thereof. In one example, sacrificial layer 506 comprises an aluminum arsenide layer. Sacrificial layer 506 may have a thickness of about 20nm or less, preferably a thickness in a range from about 1nm to about 10nm, and more preferably a thickness from about 4nm to about 6 nm. Wafer 508 may be a wafer or substrate and typically comprises gallium arsenide, gallium arsenide alloys, or other derivatives, and may be n-doped or p-doped. In one example, wafer 508 includes an n-doped gallium arsenide material. In another example, wafer 508 includes a p-doped gallium arsenide material.

In some implementations, the sacrificial layer 506 may be exposed to a wet etch solution during the etching process. The wet etch solution comprises hydrofluoric acid and may include a surfactant and/or a buffer. In some examples, sacrificial layer 506 may be etched at a rate of about 0.3 mm/hr or greater, preferably about 1 mm/hr or greater, and more preferably about 5 mm/hr or greater.

In an alternative embodiment, the sacrificial layer 506 may be exposed to an electrochemical etch during the etching process. The electrochemical etch may be a bias process or a plating process. Likewise, in another embodiment described herein, sacrificial layer 506 may be exposed to a vapor phase etch during the etching process. The vapor phase etching includes exposing the sacrificial layer 506 to hydrogen fluoride vapor. The etching process may be photochemical etching, thermally enhanced etching, plasma enhanced etching, stress enhanced etching, derivatives thereof, or combinations thereof.

Multi-layer support handle

Embodiments of the present invention generally relate to ELO thin film materials and devices, and methods for forming such materials and devices. In one embodiment, a method for forming a thin film material during an ELO process is provided, comprising: depositing or otherwise forming an epitaxial material over a sacrificial layer on a substrate; bonding a support handle to the epitaxial material; removing the sacrificial layer during the etching process; and stripping the epitaxial material from the substrate during the etching process while forming an etch crack therebetween while maintaining compression in the epitaxial material. The method further provides for: the support handle includes: a rigid support layer bonded to the epitaxial material; a soft support layer bonded to the hard support layer; and a handle plate bonded to the flexible support layer.

As shown in fig. 6A, in one embodiment, an ELO thin film stack 600A is provided, comprising: a sacrificial layer 620 disposed on or over a substrate, such as wafer 610; an epitaxial material 630 disposed on or over sacrificial layer 620; and a multi-layer support handle 670 disposed on or over the epitaxial material 630. In one example, the multi-layer support handle 670 includes: a hard support layer 640 disposed over the epitaxial material 630; a soft support layer 650 disposed over the hard support layer 640; and a handle plate 660 disposed over the flexible support layer 650. A multi-layer support handle 670 is disposed over the epitaxial material 630 and maintains its compression.

In some examples, the rigid support layer 640 may include polymers, copolymers, oligomers, derivatives thereof, or combinations thereof. In one embodiment, the rigid support layer 640 comprises a copolymer. In one example, the copolymer may be an ethylene/vinyl acetate (EVA) copolymer or a derivative thereof. The EVA copolymer used as the stiff support layer 640 is a wafer-clamping (WAFER GRIP) adhesive film commercially available from Dynatex International, located at Santa Rosa, CA. In other examples, the rigid support layer 640 may include a hot melt adhesive, an organic material or organic coating, an inorganic material, or a combination thereof.

In one embodiment, the hard support layer 640 comprises an inorganic material having a plurality of inorganic layers, such as metal layers, dielectric layers, or a combination thereof. In another example, the hard support layer 640 may include a composite or patterned composite, such as an organic/inorganic material. The composite material may comprise at least one organic material and at least one inorganic material. In some examples, the inorganic material may comprise a metal layer, a dielectric layer, or a combination thereof. The composite material may be used to optimize device performance, for example, to increase reflectivity, conductivity, and/or yield. In another embodiment, the hard support layer 640 may comprise a wax or a derivative thereof, such as a black wax.

In another embodiment, the soft support layer 650 may comprise an elastomer, such as rubber, foam, or derivatives thereof. Alternatively, the flexible support layer 650 may comprise a material such as neoprene, latex, or a derivative thereof. The soft support layer 650 may comprise a monomer. For example, the soft support layer 650 may comprise ethylene propylene diene monomer or derivatives thereof.

In another embodiment, the soft support layer 650 can comprise a liquid or fluid contained within the membrane. Optionally, the soft support layer 650 may contain a gas, which is contained inside the membrane. The membrane may comprise a material such as rubber, foam, neoprene, latex, or a derivative thereof. In one example, the membrane is a rubber or latex balloon.

In another embodiment, the handle plate 660 can comprise a material, such as a plastic, a polymer, an oligomer, derivatives thereof, or combinations thereof. In one example, the handle plate 660 can comprise polyester or derivatives thereof. The grip plate 660 may have a thickness in a range from about 50.8 μm to about 127.0 μm, for example, about 23.4 μm.

In one embodiment, the method further includes removing the sacrificial layer 620 to separate the epitaxial material 630 from the substrate, e.g., wafer 610, as shown in fig. 6A; and then bonding or attaching the epitaxial material 630 to the support substrate 680 by bonding with an adhesive therebetween to form a bonding layer 690, as shown in fig. 6B. The support substrate 680 may be bonded to the exposed surface of the epitaxial material 630 using an adhesive. In one example, the adhesive layer 690 can be formed from or include an optical adhesive and/or a uv curable adhesive, such as a commercially available Norland uv curable optical adhesive. In some examples, the binder may comprise a mercapto ester compound. In other examples, the adhesive may further comprise a material, such as butyl octyl phthalate, tetrahydrofurfuryl methacrylate, acrylate monomers, derivatives thereof, or combinations thereof.

As shown in fig. 6B, in one example, an ELO thin film stack 600B is provided, comprising: a support substrate 680 disposed over a first surface of the epitaxial material 630; and a multi-layer support handle 670 disposed over another surface of the epitaxial material 630. An adhesive layer 690 may be disposed between the epitaxial material 630 and the support substrate 680. The multi-layer support handle 670 includes: a hard support layer 640 disposed over the epitaxial material 630; a soft support layer 650 disposed over the hard support layer 640; and a handle plate 660 disposed above the flexible support layer 640.

In one example, the adhesive layer 690 can be formed from an adhesive that has been exposed to ultraviolet radiation during a curing process. In general, the adhesive may be exposed to ultraviolet radiation for a period of time in the range of from about 1 minute to about 10 minutes, preferably from about 3 minutes to about 7 minutes, for example about 5 minutes. The adhesive may be cured at a temperature in the range of from about 25 ℃ to about 75 ℃, for example about 50 ℃.

In other examples, the adhesive of the adhesive layer 690 may be a silicone adhesive, or may include sodium silicate. In these examples, the adhesive may be cured for a period of time ranging from about 10 hours to about 100 hours, preferably from about 20 hours to about 60 hours, and more preferably from about 30 hours to about 50 hours, such as about 42 hours. The adhesive may be cured at a temperature in the range of from about 25 ℃ to about 75 ℃, for example about 50 ℃. The adhesive may also be cured at a pressure in the range of from about 1psi (pounds per square inch) to about 50psi, preferably from about 3psi to about 25psi, and more preferably from about 5psi to about 15 psi. In one example, the pressure may be about 9 psi.

The sacrificial layer 620 may be exposed to an etching process to remove the epitaxial material 630 from the substrate. In some implementations, the sacrificial layer 620 may be exposed to a wet etch solution during the etching process. The wet etch solution comprises hydrofluoric acid and may include a surfactant and/or a buffer. In some examples, the sacrificial layer 620 may be etched at a rate of about 0.3 mm/hr or greater, preferably about 1 mm/hr or greater, and more preferably about 5 mm/hr or greater. In an alternative embodiment, the sacrificial layer 620 may be exposed to an electrochemical etch during the etching process. The electrochemical etch may be a bias process or a plating process. Likewise, in another embodiment described herein, the sacrificial layer 620 may be exposed to a vapor phase etch during the etching process. The vapor phase etch includes exposing the sacrificial layer 620 to hydrogen fluoride vapor. The etching process may be photochemical etching, thermally enhanced etching, plasma enhanced etching, stress enhanced etching, derivatives thereof, or combinations thereof.

In embodiments herein, the epitaxial material 630 may comprise gallium arsenide, aluminum gallium arsenide, indium gallium phosphide, alloys thereof, derivatives thereof, or combinations thereof. The epitaxial material 630 may have a rectangular geometry, a square geometry, or other geometries. Epitaxial material 630 may comprise one layer, but typically comprises multiple layers. In some examples, epitaxial material 630 includes one layer with gallium arsenide and another layer with aluminum gallium arsenide. In another example, the epitaxial material 630 includes a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer. The gallium arsenide buffer layer may have a thickness in a range from about 100nm to about 500nm, for example, about 300 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50nm, e.g., about 30 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000nm, for example, about 1000 nm. In some examples, the epitaxial material 630 further comprises a second aluminum gallium arsenide passivation layer.

In other embodiments herein, epitaxial material 630 may comprise a unit cell structure, which includes multiple layers. The cell structure may comprise 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, or combinations thereof. In many examples, gallium arsenide is n-doped or p-doped.

In some implementations, the sacrificial layer 620 can include aluminum arsenide, alloys thereof, derivatives thereof, or combinations thereof. In one example, the sacrificial layer 620 comprises an aluminum arsenide layer and has a thickness of about 20nm or less, preferably a thickness in the range from about 1nm to about 10nm, and more preferably a thickness from about 4nm to about 6 nm. The substrate, such as wafer 610 and/or support substrate 680, typically comprises gallium arsenide or derivatives thereof and may be n-doped or p-doped.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims (218)

1. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

forming an epitaxial material over a sacrificial layer on a substrate;

bonding a flattened, pre-curved support handle to the epitaxial material, wherein the flattened, pre-curved support handle is formed by flattening a curved support material, and the flattened, pre-curved support handle is under tension while the epitaxial material is under compression;

removing the sacrificial layer during an etching process; and

the epitaxial material is stripped from the substrate while forming an etched crack therebetween, and the flattened pre-curved support handle is bent to have a substantial curvature.

2. The method of claim 1, wherein the curved support material comprises a material selected from the group consisting of: waxes, polyethylenes, polyesters, polyolefins, polyethylene terephthalate polyesters, rubbers, derivatives thereof, and combinations thereof.

3. The method of claim 2, wherein the curved support material comprises polyethylene terephthalate polyester, polyolefin, or derivatives thereof.

4. The method of claim 1, wherein the curved support material comprises: a first layer comprising a wax; and a second layer comprising a polymer and disposed over the first layer.

5. The method of claim 4, wherein the second layer comprises a polyethylene terephthalate polyester or a derivative thereof.

6. The method of claim 4, wherein the curved support material further comprises a third layer comprising wax and disposed over the second layer; or a third layer comprising another polymer and disposed over the second layer.

7. The method of claim 6, wherein the third layer comprises polyethylene or a derivative thereof.

8. The method of claim 1 wherein said flattened, pre-curved support handle comprises a bottom surface and a top surface, said bottom surface being bonded to said epitaxial material and said flattened, pre-curved support handle being curved toward said top surface.

9. The method of claim 1, wherein an adhesive is used to adhere the flattened, pre-curved support handle to the epitaxial material, and the adhesive is selected from the group consisting of: pressure sensitive adhesives, hot melt adhesives, UV curable adhesives, natural adhesives, synthetic adhesives, derivatives thereof, and combinations thereof.

10. The method of claim 1, wherein the sacrificial layer is exposed to a wet etching solution during the etching process, the wet etching solution comprising hydrofluoric acid, a surfactant, and a buffer.

11. The method of claim 10, wherein the sacrificial layer is etched at a rate of about 5 mm/hr or greater.

12. The method of claim 1, wherein the 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.

13. The method of claim 12, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

14. The method of claim 13, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

15. The method of claim 14, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

16. The method of claim 14, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

17. The method of claim 1, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

18. 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.

19. The method of claim 18, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

20. The method of claim 1, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

21. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

positioning a substrate comprising an epitaxial material disposed over a sacrificial layer on the substrate;

bonding a flattened, pre-curved support handle to the epitaxial material, wherein the flattened, pre-curved support handle is formed by flattening a curved support material, and the flattened, pre-curved support handle is under tension while the epitaxial material is under compression; and

removing the sacrificial layer during an etching process, wherein the etching process further comprises:

stripping the epitaxial material from the substrate while forming an etch crack therebetween; and

the flattened pre-curved support shank is curved to have a substantial curvature.

22. A thin film stack material comprising:

a sacrificial layer disposed on the substrate;

an epitaxial material disposed over the sacrificial layer; and

a flattened pre-curved support material disposed over the epitaxial material, wherein the flattened pre-curved support material is under tension and the epitaxial material is under compression.

23. The thin film stack material of claim 22, wherein the flattened pre-curved support material comprises a material selected from the group consisting of: waxes, polyethylenes, polyesters, polyolefins, polyethylene terephthalate polyesters, rubbers, derivatives thereof, and combinations thereof.

24. The thin film stack material of claim 23, wherein the flattened, pre-curved support material comprises polyethylene terephthalate polyester, polyolefin, or derivatives thereof.

25. The thin film stack material of claim 22, wherein the flattened, pre-curved support material comprises: a first layer comprising a wax; and a second layer comprising a polymer and disposed over the first layer.

26. The thin film stack material of claim 25, wherein the second layer comprises polyethylene terephthalate polyester.

27. The thin film stack material of claim 25, wherein the flattened, pre-curved support material further comprises a third layer comprising another polymer and disposed over the second layer.

28. The thin film stack material of claim 27, wherein the third layer comprises polyethylene or a derivative thereof.

29. The thin film stack material of claim 22, wherein an adhesive is disposed between the flattened pre-curved support material and the epitaxial material, and the adhesive is selected from the group consisting of: pressure sensitive adhesives, hot melt adhesives, UV curable adhesives, natural adhesives, synthetic adhesives, derivatives thereof, and combinations thereof.

30. The thin film stack material of claim 29, wherein the 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.

31. The thin film stack material of claim 30, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

32. The thin film stack material of claim 30, wherein the epitaxial material comprises: a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer and a gallium arsenide active layer.

33. The thin film stack material of claim 32, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

34. The thin film stack material of claim 32, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

35. The thin film stack material of claim 22, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

36. The thin film stack material of claim 22, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

37. The thin film stack material of claim 36, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

38. The thin film stack material of claim 37, wherein the thickness is in a range from about 1nm to about 10 nm.

39. The thin film stack material of claim 38, wherein the thickness is in a range from about 4nm to about 6 nm.

40. The thin film stack material of claim 22, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

41. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

forming an epitaxial material over a sacrificial layer on a substrate;

bonding a support handle onto the epitaxial material, wherein the support handle comprises a shrinkable material;

shrinking the support handle during a shrinking process to create tension in the support handle and compression in the epitaxial material;

removing the sacrificial layer during an etching process; and

the epitaxial material is peeled from the substrate while forming an etching crack therebetween, and the support handle is bent to have a considerable curvature.

42. The method of claim 41, wherein the support handle comprises a material selected from the group consisting of: waxes, polyethylenes, polyesters, polyolefins, polyethylene terephthalate polyesters, rubbers, derivatives thereof, and combinations thereof.

43. The method of claim 42, wherein the support handle comprises polyethylene terephthalate polyester, polyolefin, or derivatives thereof.

44. The method of claim 41, wherein the support handle comprises: a first layer comprising a wax and a second layer comprising a polymer and disposed over the first layer.

45. The method of claim 44, wherein the second layer comprises a polyethylene terephthalate polyester or a derivative thereof.

46. The method of claim 44, wherein the support handle further comprises a third layer comprising wax and disposed over the second layer; or the support handle further comprises a third layer comprising another polymer and disposed over the second layer.

47. The method of claim 46, wherein the third layer comprises polyethylene or a derivative thereof.

48. The method of claim 41, wherein the support handle comprises a bottom surface and a top surface, the bottom surface is bonded to the epitaxial material, and the support handle is bent toward the top surface.

49. The method of claim 41 wherein the shrinkable material comprises an amorphous material and the amorphous material crystallizes during the shrinking process to undergo a net volume reduction.

50. The method of claim 41 wherein the shrinkable material comprises a material selected from the group consisting of: plastics, rubbers, polymers, oligomers, derivatives thereof, and combinations thereof.

51. The method of claim 41 wherein the shrinkable material comprises polyester or derivatives thereof.

52. The method of claim 41, wherein the support handle comprises a heat shrink polymer and the support handle is heated during the shrinking process.

53. The method of claim 41, wherein an adhesive is used to adhere the support handle to the epitaxial material, and the adhesive is selected from the group consisting of: pressure sensitive adhesives, hot melt adhesives, UV curable adhesives, natural adhesives, synthetic adhesives, derivatives thereof, and combinations thereof.

54. The method of claim 41, wherein the sacrificial layer is exposed to a wet etching solution during the etching process, the wet etching solution comprising hydrofluoric acid, a surfactant, and a buffer.

55. The method of claim 54, wherein the sacrificial layer is etched at a rate of about 5 mm/hr or greater.

56. The method of claim 41, wherein the sacrificial layer is exposed to hydrogen fluoride vapor during the etching process.

57. The method of claim 41, wherein the 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.

58. The method of claim 57, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

59. The method of claim 57, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

60. The method of claim 59, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

61. The method of claim 59, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

62. The method of claim 41, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

63. The method of claim 41, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

64. The method of claim 63, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

65. The method of claim 41, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

66. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

positioning a substrate comprising an epitaxial material disposed over a sacrificial layer on the substrate;

bonding a support handle onto the epitaxial material, wherein the support handle comprises a shrinkable material;

shrinking the support handle during a shrinking process to create tension in the support handle and compression in the epitaxial material; and

removing the sacrificial layer during an etching process, wherein the etching process further comprises:

stripping the epitaxial material from the substrate;

forming an etch crack between the epitaxial material and the substrate; and

the support handle is bent to have a considerable curvature.

67. A thin film stack material comprising:

a sacrificial layer disposed on the substrate;

an epitaxial material disposed over the sacrificial layer; and

a support handle configured over the epitaxial material, wherein the support handle comprises a shrinkable material that, when shrunk, creates tension in the support handle and compression in the epitaxial material.

68. The thin film stack material of claim 67, wherein the shrinkable material comprises an amorphous material that crystallizes during a shrinking process to undergo a net volume reduction.

69. The thin film stack material of claim 67, wherein the shrinkable material comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

70. The thin film stack material of claim 67, wherein the support handle comprises a heat shrink polymer.

71. The thin film stack material of claim 67, wherein an adhesive is between the support handle and the epitaxial material, and the adhesive is selected from the group consisting of: pressure sensitive adhesives, hot melt adhesives, UV curable adhesives, natural adhesives, synthetic adhesives, derivatives thereof, and combinations thereof.

72. The thin film stack material of claim 67, 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.

73. The thin film stack material of claim 72, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

74. The thin film stack material of claim 72, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

75. The thin film stack material of claim 74, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

76. The thin film stack material of claim 72, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

77. The thin film stack material of claim 67, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

78. The thin film stack material of claim 67, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

79. The thin film stack material of claim 78, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

80. The thin film stack material of claim 79, wherein the thickness is in a range from about 1nm to about 10 nm.

81. The thin film stack material of claim 80, wherein the thickness is in a range from about 4nm to about 6 nm.

82. The thin film stack material of claim 67, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

83. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

forming an epitaxial material over a sacrificial layer on a substrate;

bonding a support handle to the epitaxial material, wherein the support handle comprises a shrinkable material and reinforcing fibers extending unidirectionally through the shrinkable material;

shrinking the support handle tangent to the reinforcing fiber during a shrinking process to create tension in the support handle and compression in the epitaxial material;

removing the sacrificial layer during an etching process; and

the epitaxial material is peeled from the substrate while forming an etching crack therebetween, and the support handle is bent to have a considerable curvature.

84. The method of claim 83, wherein the support handle includes a bottom surface and a top surface, the bottom surface is bonded to the epitaxial material, and the support handle is bent toward the top surface.

85. The method according to claim 83 wherein the shrinkable material comprises an amorphous material that crystallizes during the shrinking process to undergo a net volume reduction.

86. The method of claim 83 wherein the shrinkable material comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

87. The method of claim 83 wherein the shrinkable material comprises polyester or derivatives thereof.

88. The method of claim 83, wherein the reinforcing fibers are high strength polymer fibers.

89. The method of claim 88, wherein the reinforcing fibers comprise polyethylene or derivatives thereof.

90. The method of claim 88, wherein the reinforcing fiber comprises a negative linear coefficient of thermal expansion along the length of the fiber.

91. The method of claim 88, wherein the reinforcing fiber comprises a tensile modulus in a range from about 15GPa to about 134 GPa.

92. The method of claim 83, wherein the support handle is heated during the shrinking process and the support handle comprises a heat shrinkable polymer and high strength polymer fibers.

93. The method of claim 83 wherein shrinking the support handle includes removing solvent from the shrinkable material.

94. The method of claim 83, wherein an adhesive is used to adhere the support handle to the epitaxial material, and the adhesive is selected from the group consisting of: pressure sensitive adhesives, hot melt adhesives, UV curable adhesives, natural adhesives, synthetic adhesives, derivatives thereof, and combinations thereof.

95. The method of claim 83, wherein the sacrificial layer is exposed to a wet etching solution during the etching process, the wet etching solution comprising hydrofluoric acid, a surfactant, and a buffer.

96. The method of claim 95, wherein the sacrificial layer is etched at a rate of about 5 mm/hr or greater.

97. The method of claim 83, wherein the sacrificial layer is exposed to hydrogen fluoride vapor during the etching process.

98. The method of claim 83, wherein the 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.

99. The method of claim 98, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

100. The method of claim 98, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

101. The method of claim 100, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

102. The method of claim 100, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

103. The method of claim 83, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

104. The method of claim 83, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

105. The method of claim 104, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

106. The method of claim 83, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

107. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

positioning a substrate comprising an epitaxial material disposed over a sacrificial layer on the substrate;

bonding a support handle to the epitaxial material, wherein the support handle comprises a shrinkable material and reinforcing fibers extending unidirectionally through the shrinkable material;

shrinking the support handle tangent to the reinforcing fiber during a shrinking process to create tension in the support handle and compression in the epitaxial material; and

removing the sacrificial layer during an etching process, wherein the etching process further comprises:

stripping the epitaxial material from the substrate;

forming an etch crack between the epitaxial material and the substrate; and

the support handle is bent to have a considerable curvature.

108. A thin film stack material comprising:

a sacrificial layer disposed on the substrate;

an epitaxial material disposed over the sacrificial layer; and

a support handle disposed over the epitaxial material, wherein the support handle comprises a shrinkable material and a reinforcing fiber, the reinforcing fiber extending unidirectionally through the shrinkable material, the shrinkable material shrinking tangentially to the reinforcing fiber upon shrinking to create tension in the support handle and compression in the epitaxial material.

109. The thin film stack material of claim 108, wherein the shrinkable material comprises an amorphous material that crystallizes during the shrinking process to undergo a net volume reduction.

110. The thin film stack material of claim 108, wherein the shrinkable material comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

111. The thin film stack material of claim 108, wherein the reinforcing fibers are high strength polymer fibers.

112. The thin film stack material of claim 108, wherein the reinforcing fibers comprise polyethylene.

113. The thin film stack material of claim 108, wherein the reinforcing fibers comprise a negative linear coefficient of thermal expansion along the length of the fibers.

114. The thin film stack material of claim 108, wherein the reinforcing fibers comprise a tensile modulus in a range from about 15GPa to about 134 GPa.

115. The thin film stack material of claim 108, wherein the support handle comprises a heat shrink polymer and high strength polymer fibers.

116. The thin film stack material of claim 108, wherein an adhesive is between the support handle and the epitaxial material, and the adhesive is selected from the group consisting of: pressure sensitive adhesives, hot melt adhesives, UV curable adhesives, natural adhesives, synthetic adhesives, derivatives thereof, and combinations thereof.

117. The thin film stack material of claim 108, wherein the 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.

118. The thin film stack material of claim 117, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

119. The thin film stack material of claim 117, wherein the epitaxial material comprises: a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer and a gallium arsenide active layer.

120. The thin film stack material of claim 119, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

121. The thin film stack material of claim 119, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

122. The thin film stack material of claim 108, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

123. The thin film stack material of claim 108, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

124. The thin film stack material of claim 123, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

125. The thin film stack material of claim 124, wherein the thickness is in a range from about 1nm to about 10 nm.

126. The thin film stack material of claim 125, wherein the thickness is in a range from about 4nm to about 6 nm.

127. The thin film stack material of claim 108, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

128. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

forming an epitaxial material over a sacrificial layer on a substrate;

bonding a support handle onto the epitaxial material, wherein the support handle comprises a wax film having a varying thickness;

removing the sacrificial layer during an etching process; and

during the etching process, the epitaxial material is stripped from the substrate while forming an etch crack therebetween and the support handle is bent to form a compression in the epitaxial material.

129. The method of claim 128, wherein the support handle comprises a bottom surface of the wax film and a top surface of a flexible member, the bottom surface is bonded to the epitaxial material, and the support handle is bent toward the top surface.

130. The method of claim 129, wherein the flexible member comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

131. The method of claim 129, wherein the flexible member comprises polyester or derivatives thereof.

132. The method of claim 128, wherein the wax film comprises a wax having a softening point temperature in a range from about 65 ℃ to about 95 ℃.

133. The method of claim 132, wherein the softening point temperature is in the range of from about 80 ℃ to about 90 ℃.

134. The method of claim 132, wherein the varying thickness of the wax film is thinnest in or near the center of the wax film.

135. The method of claim 132, wherein the varying thickness of the wax film is thickest in or near the center of the wax film.

136. The method of claim 128, wherein the sacrificial layer is exposed to a wet etching solution during the etching process, the wet etching solution comprising hydrofluoric acid, a surfactant, and a buffer.

137. The method of claim 136, wherein the sacrificial layer is etched at a rate of about 5 mm/hr or greater.

138. The method of claim 128, wherein the sacrificial layer is exposed to hydrogen fluoride vapor during the etching process.

139. The method of claim 128, wherein the 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.

140. The method of claim 139, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

141. The method of claim 139, wherein the epitaxial material comprises: a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer and a gallium arsenide active layer.

142. The method of claim 141, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

143. The method of claim 141, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

144. The method of claim 128, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

145. The method of claim 128, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

146. The method of claim 145, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

147. The method of claim 128, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

148. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

positioning a substrate comprising an epitaxial material disposed over a sacrificial layer on the substrate;

bonding a support handle onto the epitaxial material, wherein the support handle comprises a wax film having a varying thickness; and

removing the sacrificial layer during an etching process, wherein the etching process further comprises:

stripping the epitaxial material from the substrate;

forming an etch crack between the epitaxial material and the substrate; and

during the etching process, the support handle is bent to form a compression in the epitaxial material.

149. A thin film stack material comprising:

a sacrificial layer disposed on the substrate;

an epitaxial material disposed over the sacrificial layer; and

a support handle configured over the epitaxial material, wherein the support handle comprises a wax film having a varying thickness.

150. The thin film stack material of claim 149, wherein the support handle comprises a bottom surface of the wax film and a top surface of a flexible member, and the bottom surface is bonded to the epitaxial material.

151. The thin film stack material of claim 150, wherein the flexible member comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

152. The thin film stack material of claim 150, wherein the flexible member comprises polyester or derivatives thereof.

153. The thin film stack material of claim 150, wherein the flexible member comprises a film thickness in a range from about 50.8 μ ι η to about 127.0 μ ι η.

154. The thin film stack material of claim 149, wherein the wax film comprises a wax having a softening point temperature in a range from about 65 ℃ to about 95 ℃.

155. The thin film stack material of claim 154, wherein the softening point temperature is in a range from about 80 ℃ to about 90 ℃.

156. The thin film stack material of claim 154, wherein the varying thickness of the wax film is thinnest at or near the center of the wax film.

157. The thin film stack material of claim 154, wherein the varying thickness of the wax film is thickest at or near a center of the wax film.

158. The thin film stack material of claim 154, wherein the varying thickness of the wax film is in a range from about 1 μ ι η to about 100 μ ι η.

159. The thin film stack material of claim 154, wherein the varying thickness of the wax film comprises a thinnest section and a thickest section.

160. The thin film stack material of claim 159, wherein the thinnest section has a thickness in a range from about 1 μm to about 25 μm.

161. The thin film stack material of claim 159, wherein the thickest section has a thickness in the range of from about 25 μ ι η to about 100 μ ι η.

162. The thin film stack material of claim 149, wherein the 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.

163. The thin film stack material of claim 162, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

164. The thin film stack material of claim 162, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

165. The thin film stack material of claim 164, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

166. The thin film stack material of claim 164, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

167. The thin film stack material of claim 149, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

168. The thin film stack material of claim 149, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

169. The thin film stack material of claim 168, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness of about 20nm or less.

170. The thin film stack material of claim 169, wherein the thickness ranges from about 1nm to about 10 nm.

171. The thin film stack material of claim 170, wherein the thickness is in a range from about 4nm to about 6 nm.

172. The thin film stack material of claim 149, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.

173. A method for forming a thin film material during an epitaxial migration process, comprising the steps of:

forming an epitaxial material over a sacrificial layer on a substrate;

bonding a support handle onto the epitaxial material, wherein the support handle comprises: a rigid support layer bonded to the epitaxial material; a soft support layer bonded to the hard support layer; and a handle plate bonded to the flexible support layer;

removing the sacrificial layer during an etching process; and

during the etching process, the epitaxial material is stripped from the substrate while forming etch cracks therebetween while maintaining compression in the epitaxial material.

174. The method of claim 173, further comprising removing the epitaxial material from the substrate.

175. The method of claim 174 further comprising attaching a support substrate to an exposed surface of the epitaxial material.

176. The method of claim 174, wherein the support substrate is adhesively bonded to the exposed surface of the epitaxial material.

177. The method of claim 176, wherein the adhesive is an optical adhesive or a UV-curable adhesive.

178. The method of claim 176, wherein the adhesive further comprises a material selected from the group consisting of: butyl octyl phthalate, tetrahydrofurfuryl methacrylate, acrylate monomers, derivatives thereof, and combinations thereof.

179. The method of claim 176, wherein the adhesive is a silicone adhesive, or the adhesive comprises sodium silicate.

180. The method of claim 176, wherein the adhesive is cured for a period of time ranging from about 20 hours to about 60 hours at a temperature ranging from about 25 ℃ to about 75 ℃ and at a pressure ranging from about 5psi to about 15 psi.

181. The method of claim 173, wherein the stiff support layer comprises a material selected from the group consisting of: polymers, copolymers, oligomers, derivatives thereof, and combinations thereof.

182. The method of claim 181, wherein the stiff support layer comprises an ethylene/vinyl acetate copolymer or a derivative thereof.

183. The method of claim 173, wherein the stiff support layer comprises a material selected from the group consisting of: hot melt adhesives, organic materials, organic coatings, inorganic materials, and combinations thereof.

184. The method of claim 183, wherein the stiff support layer comprises a plurality of layers of inorganic materials, and the plurality of layers further comprises a metal layer, a dielectric layer, or a combination thereof.

185. The method of claim 173, wherein the soft support layer comprises an elastomer, and the elastomer comprises rubber, foam, or derivatives thereof.

186. The method of claim 173, wherein the soft support layer comprises a material selected from the group consisting of: neoprene, latex, and derivatives thereof.

187. The method of claim 173, wherein the soft support layer comprises ethylene propylene diene monomer or a derivative thereof.

188. The method of claim 173, wherein the handle plate comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

189. The method of claim 173, wherein the handle plate comprises polyester or a derivative thereof.

190. The method of claim 173, wherein the sacrificial layer is exposed to a wet etching solution during the etching process, the wet etching solution comprising hydrofluoric acid, a surfactant, and a buffer.

191. The method of claim 173, wherein the sacrificial layer is etched at a rate of about 5 mm/hr or greater.

192. The method of claim 173, wherein the sacrificial layer is exposed to hydrogen fluoride vapor during the etching process.

193. The method of claim 173, wherein the 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.

194. The method of claim 193, wherein the epitaxial material comprises: one layer comprising gallium arsenide and another layer comprising aluminum gallium arsenide.

195. The method of claim 194, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

196. The method of claim 195, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

197. The method of claim 195, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

198. The method of claim 173, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure comprising 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.

199. The method of claim 173, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

200. The method of claim 199, wherein the sacrificial layer comprises an aluminum arsenide layer having a thickness in a range from about 1nm to about 10 nm.

201. A thin film stack material comprising:

a sacrificial layer disposed on the substrate;

an epitaxial material disposed over the sacrificial layer; and

a support handle configured over the epitaxial material, wherein the support handle comprises:

a hard support layer configured over the epitaxial material;

a soft support layer disposed above the hard support layer; and

a handle plate disposed above the flexible support layer.

202. The thin film stack material of claim 201, wherein the epitaxial material is under compression.

203. The thin film stack material of claim 201, wherein the stiff support layer comprises an ethylene/vinyl acetate copolymer or a derivative thereof.

204. The thin film stack material of claim 201, wherein the stiff support layer comprises a material selected from the group consisting of: hot melt adhesives, organic coatings, organic materials, inorganic materials, and combinations thereof.

205. The thin film stack material of claim 204, wherein the stiff support layer comprises a plurality of layers of inorganic materials, and the plurality of layers further comprise a metal layer, a dielectric layer, or a combination thereof.

206. The thin film stack material of claim 201, wherein the soft support layer comprises an elastomer, and the elastomer comprises rubber, foam, or derivatives thereof.

207. The thin film stack material of claim 201, wherein the soft support layer comprises a material selected from the group consisting of: neoprene, latex, and derivatives thereof.

208. The thin film stack material of claim 201, wherein the soft support layer comprises an ethylene propylene diene monomer or a derivative thereof.

209. The thin film stack material of claim 201, wherein the handle plate comprises a material selected from the group consisting of: plastics, polymers, oligomers, derivatives thereof, and combinations thereof.

210. The thin film stack material of claim 209, wherein the handle plate comprises polyester or derivatives thereof.

211. The thin film stack material of claim 209, wherein the handle plate has a thickness in a range from about 50.8 μ ι η to about 127.0 μ ι η.

212. The thin film stack material of claim 201, wherein the 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.

213. The thin film stack material of claim 212, wherein the epitaxial material comprises a gallium arsenide buffer layer, an aluminum gallium arsenide passivation layer, and a gallium arsenide active layer.

214. The thin film stack material of claim 213, wherein the gallium arsenide buffer layer has a thickness in a range from about 100nm to about 500 nm; the aluminum gallium arsenide passivation layer has a thickness in a range from about 10nm to about 50 nm; and the gallium arsenide active layer has a thickness in a range from about 500nm to about 2000 nm.

215. The thin film stack material of claim 213, wherein the epitaxial material further comprises a second aluminum gallium arsenide passivation layer.

216. The thin film stack material of claim 201, wherein the epitaxial material comprises a unit cell structure comprising multiple layers, the unit cell structure 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.

217. The thin film stack material of claim 201, wherein the sacrificial layer comprises a material selected from the group consisting of: aluminum arsenide, alloys thereof, derivatives thereof, and combinations thereof.

218. The thin film stack material of claim 201, wherein the substrate comprises gallium arsenide, n-doped gallium arsenide, p-doped gallium arsenide, or derivatives thereof.