WO2016141132A1

WO2016141132A1 - Methods and apparatus for controlling and initiating de-bonding of substrates from carriers

Info

Publication number: WO2016141132A1
Application number: PCT/US2016/020593
Authority: WO
Inventors: Eric Lewis ALLINGTON; Claire Renata COBLE; Xinghua Li; Anping Liu
Original assignee: Corning Incorporated
Priority date: 2015-03-04
Filing date: 2016-03-03
Publication date: 2016-09-09
Also published as: TW201705244A

Abstract

A method of processing a substrate is provided that includes the steps: obtaining a carrier having first and second primary surfaces, and a plurality of edges; obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier using a surface modification layer to define a bond region between the carrier and the substrate; and directing a thermal input to an outer portion of the carrier or an outer portion of the substrate to produce a thermal-assisted mechanical stress in a portion of the bond region. Further, the directing step is conducted for a thermal input time sufficient to reduce a separation force for separating the carrier from the substrate after the bonding step and any additional thermal processing of the substrate prior to the directing step.

Description

METHODS AND APPARATUS FOR CONTROLLING AND INITIATING DE- BONDING OF SUBSTRATES FROM CARRIERS

BACKGROUND

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial Nos. 62/160779 filed on May 13, 2015, U. S. Provisional Application Serial No. 62/153168 filed on April 27, 2015, and U. S. Provisional Application Serial No. 62/128468 filed on March 4, 2015, the contents of each of which are relied upon and incorporated herein by reference in their entireties.

FIELD OF THE INVENTION

[0002] The present invention is directed to methods for processing of substrates on carriers and, more particularly to methods for controlling and initiating de-bonding of glass, glass-ceramic and ceramic substrates, including flexible glass substrates, from carriers.

TECHNICAL BACKGROUND

[0003] Flexible substrates offer the promise of cost-effective devices using roll-to-roll processing, and the potential to make thinner, lighter, more flexible and durable displays. However, the technology, equipment, and processes required for roll-to-roll processing of high quality displays remain in an emerging state of development. Since panel makers involved in the manufacture of conventional display devices have already heavily invested in toolsets to process large sheets of glass of a particular thickness, laminating a thin, flexible substrate to a thicker carrier and making display devices by a sheet-to-sheet method offers a shorter term solution to develop the value proposition of thinner, lighter, and more flexible displays. Displays have been demonstrated on polymer sheets, for example, polyethylene naphthalate (PEN). In particular, the device fabrication processes for such displays was sheet-to- sheet with the PEN laminated to a glass carrier. Nevertheless, the upper temperature limit of the PEN limits the device quality and processes that can be used. In addition, the high permeability of the polymer substrate leads to environmental degradation of OLED devices whereas, instead, a near hermetic package is more beneficial.

[0004] In a similar manner, flexible display devices can be manufactured using a glass carrier laminated to one or more flexible, thin glass substrates. It is anticipated that the low permeability and improved temperature and chemical resistance of the thin glass will enable higher performance and longer lifetime flexible displays. To that end, flexible glass substrates have been laminated to glass carriers using adhesion layers to develop bonds having moderate bond energies. Subsequently, active devices, including thin film transistor (TFT) elements, have been processed on the flexible glass substrates at relatively high temperatures. Accordingly, the bonds between the glass carriers and the substrate possess a bond energy sufficient to withstand temperatures associated with downstream device processing (e.g., active device formation), yet weak enough to facilitate separation of the carrier from the substrates after such downstream processing steps have been completed.

[0005] Similarly, semiconductor devices can be fabricated by forming active devices on a semiconductor wafer substrate. The semiconductor wafer may comprise, for example, glass, silicon, polysilicon, single crystal silicon, silicon oxide, aluminum oxide, combinations of these, and/or the like. Hundreds or thousands of integrated circuits (ICs) or dies are typically manufactured on a single wafer. Typically, a plurality of insulating, conductive, and semiconductive material layers are sequentially deposited and patterned over the wafer to form the ICs.

[0006] After the ICs are formed, the wafer may be subjected to backside processing. The backside processing may include thinning the wafer to prepare the wafer for packaging. For example, in some technologies, backside processing may include forming electrical connections to through-substrate vias formed through the wafer for providing backside contacts. In this example, the backside of the wafer is thinned through a process such as grinding in order to expose the conductive vias on the backside of the wafer. This process of thinning the wafer can damage the edges of the wafer and can make the wafer even more fragile and susceptible to damage during subsequent transportation and processing of the wafer.

[0007] To help alleviate these types of damage, a carrier is often attached to the wafer. This carrier is attached using an adhesive, and is intended to allow handling of the wafer by handling the carrier. Further, the carriers in many applications are attached to the wafer prior to manufacturing and process steps for developing the active devices on the wafer.

Accordingly, adhesion layers can be used to develop bonds having moderate bond energies between the carriers and the wafers, similar to the adhesion layers.

[0008] At some point after the development of active devices on the flexible substrates, semiconductor wafers and other glass, glass-ceramic and ceramic substrates bonded to carriers, the carriers must be removed from the substrates. This removal process can be referred to as a "de-bond" process. A typical de-bonding process can include the insertion of a sharp blade (for example, a razor blade) into a gap between the carrier and the substrate to "initiate" the separation of the carrier from the substrate. After the "initiation," one or more mechanical fixtures can be used to slowly separate the carrier and the substrate.

[0009] These mechanically-oriented de-bonding procedures involve significant physical contact between the fixtures, blades and other hard and/or sharp apparatus with the carriers and substrates. Consequently, these de-bonding processes are prone to the development of defects, chips, scratches and other flaws in the carriers, substrates and/or any active electronic device elements developed on the substrates. As a result, conventional de-bonding processes are prone to low yields and high production costs.

SUMMARY

[0010] In view of the foregoing considerations, there is a need for de-bonding processes and apparatus that limit or otherwise eliminate the physical contact and other avenues for the development of defects, flaws and the like in the substrates, carriers and any electronic device elements developed on the substrates.

[0011] According to one aspect of the disclosure, a method of processing a substrate is provided that includes: obtaining a carrier having first and second primary surfaces; obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier using a surface modification layer to define a bond region between the carrier and the substrate; and directing a thermal input to a portion of the second primary surface of the carrier to produce a thermal- assisted mechanical stress in a portion of the bond region. Further, the directing step is conducted for a thermal input time sufficient to reduce a separation force for separating the carrier from the substrate after the bonding step and any additional thermal processing of the substrate prior to the directing step.

[0012] According to an additional aspect of the disclosure, a method of processing a substrate is provided that includes: obtaining a carrier having first and second primary surfaces, and a plurality of edges; obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier using a surface modification layer to define a bond region between the carrier and the substrate; and directing a thermal input to a portion of one of the edges of the carrier to produce a thermal-assisted mechanical stress in a portion of the bond region. In addition, the directing step is conducted for a thermal input time sufficient to reduce a separation force for separating the carrier from the substrate after the bonding step and any additional thermal processing of the substrate prior to the directing step.

[0013] According to a further aspect of the disclosure, a method of processing a substrate is provided that includes: obtaining a carrier having first and second primary surfaces, and a plurality of edges; obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier using a surface modification layer to define a bond region between the carrier and the substrate; and directing a thermal input to an outer portion of the carrier or an outer portion of the substrate to produce a thermal-assisted mechanical stress in a portion of the bond region. Further, the directing step is conducted for a thermal input time sufficient to reduce a separation force for separating the carrier from the substrate after the bonding step and any additional thermal processing of the substrate prior to the directing step.

[0014] In the foregoing methods, the carrier can be fabricated from one or more materials having a glass, glass-ceramic, or ceramic composition. In certain embodiments of the foregoing methods, the substrate is a flexible substrate having a glass composition (e.g. , Corning® Willow® glass) and a thickness of 300 μιτι or less (for example, 300, 275, 250, 225, 200, 175, 150, 125, 100, 75, 50, or 25 μιτι), and the carrier has a glass composition (e.g., Corning® Eagle XG® glass) and a thickness from about 200 μιτι to about 1 mm (for example, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950 and 1000 μηι). In addition, the substrate can contain one or more optoelectronic device elements, active devices, TFTs, color filter array elements, and other elements employed in

semiconductor devices, display devices and the like utilizing the substrate.

[0015] In certain aspects, the thermal input can be generated by a laser or another heat source capable of providing high thermal energies within a small outer region of the carrier (e.g. , 500 to 3000 mm²) and/or the substrate for a relatively short duration (e.g., less than 10 seconds). For example, the thermal input time can be limited to 2 seconds or less (for example about 1 second) when the thermal input is provided by a laser source.

[0016] According to certain aspects, the bonding step can be conducted to define a bond region having an adhesion energy between about 300 mJ/m² and 800 mJ/m². In some aspects, the bond region may exhibit an adhesion energy between about 300 mJ/m² and 500 mJ/m². Further, the surface modification layer can comprise hexamethyldisilazane (HMDS), a plasma-polymerized fluoropolymer, or an aromatic silane, for example.

[0017] According to certain implementations of the foregoing methods, the directing step can be conducted to de-bond the substrate from the carrier without further mechanical assistance. That is, the directing step can be conducted for a predetermined time sufficient to separate at least a portion of the carrier from the substrate in a portion of the bond region. In other implementations, the directing step can be conducted for a thermal input time sufficient to reduce the separation force by at least 50%. In addition, the directing step can be conducted such that it also produces a displacement of a portion of the carrier relative to the substrate and/or a portion of the substrate relative to the carrier, the displacement being monitored by apparatus to control the thermal input time. In certain implementations, the methods can include a step of separating the carrier from the substrate at a force greater than or equal to the separation force that exists between the carrier and the substrate after the directing step has been completed (i.e., after the de-bonding process step or steps have been completed).

[0018] According to an additional aspect of the disclosure, an apparatus for processing a substrate is provided. The apparatus includes: a carrier engagement member comprising an engagement surface for removable coupling to a primary surface of a carrier; and a substrate engagement member comprising an engagement surface for removable coupling to a primary surface of a substrate having a silicon, glass, glass-ceramic, or ceramic composition, the substrate bonded to the carrier with a surface modification layer to define a bond region between the carrier and the substrate. The apparatus also includes a thermal source arranged to direct a thermal input upon an outer portion of one of the carrier and the substrate. Further, the thermal source and the engagement members are collectively arranged to control the thermal input upon the outer portion to produce a thermal-assisted mechanical stress in the bond region for a thermal input time sufficient to reduce a separation force for separating the substrate bonded to the carrier.

[0019] Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from the description or recognized by practicing the various aspects as exemplified in the written description and the appended drawings. It is to be understood that both the foregoing general description and the following detailed description are merely exemplary of the various aspects, and are intended to provide an overview or framework to understanding the nature and character of the invention as it is claimed.

[0020] The accompanying drawings are included to provide a further understanding of principles of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiment(s), and together with the description serve to explain, by way of example, principles and operation of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] FIG. 1 A is a schematic side view of a substrate (bonded to a carrier) during a de- bonding process step in which a laser is directed upon a primary surface of the carrier to initiate de-bonding of the substrate from the carrier.

[0022] FIG. IB is a schematic side view of a substrate (bonded to a carrier) during a de- bonding step in which a laser is directed upon an edge of the carrier to initiate de-bonding of the substrate from the carrier.

[0023] FIG. 2 is a perspective view of a pair of substrates (with primary surfaces bonded to a pair of carriers) during a de-bonding process step in which a laser is directed upon a primary surface of one of the carriers to initiate a de-bonding of the substrate from the carrier.

[0024] FIG. 2A is a plan view schematic of the portion of the primary surface of the carrier irradiated with a laser depicted in FIG. 2.

[0025] FIG. 3 is a schematic side view of a substrate (bonded to a carrier) during a de- bonding process step in which a laser is directed upon a primary surface of the carrier to initiate a de-bonding of the substrate from the carrier and a position detection apparatus is employed to monitor displacement of the carrier during the de-bonding process step.

[0026] FIG. 4A is a plan view schematic of a light beam partem generated by the position detection apparatus depicted in FIG. 3.

[0027] FIG. 4B is a plan view schematic of a light beam partem reflected by the portion of the primary surface of the carrier irradiated by the laser and detected by the position detection apparatus depicted in FIG. 3.

DETAILED DESCRIPTION

[0028] In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth to provide a thorough understanding of various principles of the present invention. However, it will be apparent to one having ordinary skill in the art, having had the benefit of the present disclosure, that the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of various principles of the present invention. Finally, wherever applicable, like reference numerals refer to like elements.

[0029] Ranges can be expressed herein as from "about" one particular value, and/or to "about" another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent "about," it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0030] Directional terms as used herein— for example up, down, right, left, front, back, top, bottom— are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0031] As used herein, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to a "component" includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0032] The disclosure is generally directed to methods and apparatus for controlling and initiating de-bonding of silicon, glass, glass-ceramic and ceramic substrates, including flexible glass substrates, from carriers through thermal inputs. To process thin substrates, i.e., those having a thickness of 300 microns or less, for example 300, 275, 250, 225, 200, 175, 150, 125, 100, 75, 50, 20, or 10 microns, in existing equipment designed for processing thicker sheets, the thin substrates are temporarily bonded with a carrier to form a sheet assembly having a thickness appropriate for the particular processing equipment. The thin substrate may be a thin silicate glass sheet, for example, on which electronic devices are to be built, wherein the electronic device benefits from the high temperature processing capability and hermeticity of the silicate glass (for simplicity sake, the terms "glass sheet" and "glass substrate" are used herein to refer to a silicate glass sheet).

[0033] In general, the glass substrate is bonded to the carrier with a temporary bonding agent (e.g. , a surface modification layer) to form a sheet assembly in which the thin substrate and carrier can be separated from one another after processing associated with the substrate has been completed. The sheet assembly is processed, for example to fabricate electronic device components onto the thin substrate, and then the thin substrate is removed from the carrier. For example, the sheet assembly can include: multiple thin sheets stacked together and temporarily bonded on one carrier; or a stack having a first thin sheet temporarily bonded to a first carrier, a second thin sheet temporarily bonded to a second carrier, wherein the first and second thin sheets are permanently bonded to one another as part of an electronic device. In the latter case, the two thin sheets may have been separately processed on their respective carriers to form, for example, a thin film transistor (TFT) backplane, and a color filter, for a liquid crystal display (LCD) device. The two thin sheets are then permanently bonded to one another around their perimeters to form an LCD pane. Upon completion of the LCD panel, the two carriers are removed therefrom.

[0034] In the foregoing situations, the de-bonding initiation described herein may be used to facilitate the peeling or removal of the carrier(s) from the substrates (e.g., thin glass sheets). To remove the thin substrate from the carrier, when the thin substrate is a glass sheet, it is beneficial to initiate a local de-bonding, i.e., at an area smaller than the entire area over which the sheets were bonded for the processing. Once de-bonding has been initiated, the thin glass sheet can be peeled from the carrier using mechanical levers or other fixtures, for example. By initiating de-bonding on a portion of the area over which the thin glass sheet is bonded to the carrier (e.g., without any physical contact of a blade or the like in the portion of the area), there is a reduced risk of breaking the thin glass sheet than when attempting to peel the thin glass sheet from the carrier without de-bonding initiation. That is, the force to initiate de- bonding is greater than that to maintain peeling of the thin sheet from the carrier after peeling has started. Thus, if one were to attempt to initiate de-bonding and peel in one motion, the higher force for initiation would also be used to maintain peeling, which would increase the risk of breaking or otherwise damaging the thin sheet or carrier. On the other hand, when firstly initiating de-bonding and then peeling in two separate actions, the de-bonding initiation can be performed at the higher required force, and the peeling can be performed at a lower force, thereby reducing the risk of breaking or otherwise damaging the thin sheet or carrier. Further, separation of the sheets is initiated by laser beam or other suitable heat- generating source preferentially directed toward an outer portion of the substrate or the carrier to rapidly heat up a small area of the outer portion, thereby inducing some relative displacement of the substrate relative to the carrier based in part on the resulting thermal gradient developed within the respective outer portion of the substrate or carrier.

Accordingly, two sheets of an assembly, for example an ultra-thin glass and a carrier, can be separated without damaging the sheets, whereby the carrier can be used again in another process, and the electronic device built on the ultra-thin glass is not damaged, resulting in a higher yield for the device manufacturer.

[0035] In general, the disclosure is directed to methods and apparatus for controlling and initiating de-bonding of a sheet assembly, e.g., a substrate that has been temporarily bonded to a carrier with a surface modification layer. A laser beam or other suitable heat-generating source is preferentially directed toward an outer portion of the substrate or the carrier to rapidly heat up a small area of the outer portion, thereby inducing some relative displacement of the substrate relative to the carrier based in part on the resulting thermal gradient developed within the respective outer portion of the substrate or carrier. This relative displacement generates mechanical stresses in or within the vicinity of the bond region between the substrate and carrier that reduces the force required to separate the substrate from the carrier. Consequently, the force required to separate the carrier from the substrate is reduced, facilitating an easier de-bonding process and increasing manufacturing yields.

[0036] The processes and associated apparatus outlined in the disclosure offer various advantages over conventional de-bonding approaches for substrates and carriers. A key advantage of these processes is that they do not rely on any physical contact between fixtures, tooling or the like with the substrate and carrier interfaces, thus reducing the potential for damage and process variability. Another advantage is that the de-bonding initiation processes of the disclosure can be conducted over a short duration, in as little as two seconds or less. A further advantage is that the processes and apparatus of the disclosure can be flexibly applied and tailored to various substrate/carrier systems. Further, the use of a laser (or other suitable device for generating heat in a small region over a short time period) affords process flexibility as the laser heat input can be precisely controlled to achieve the necessary thermal-assisted mechanical stresses in the bond region between the substrate and the carrier to initiate or facilitate de-bonding without reaching stress levels in the bulk of the substrate and carrier that could lead to failure of these components. An additional advantage is that the de-bonding apparatus employing a laser can be scaled to cover various

substrate/carrier geometries given the ability of many laser arrangements to raster over various, pre-defined scanning areas. [0037] Referring to FIG. 1A, a method 300a for processing a substrate is depicted. A substrate 100 is temporarily bonded to a carrier 150 with a surface modification layer 130. A fixture 11 (e.g., a vacuum fixture) is removably attached to the substrate 100 as shown, preferably to one of its primary surfaces. The carrier 150 has a second primary surface 152 and a first primary surface 154. One or more fixtures 11 can be alternatively, or additionally, removably attached to the carrier 150 during the method 300a, preferably to one of the primary surfaces 152, 154. As shown more particularly in FIG. 1A, the first primary surface 154 of the carrier 150 is temporarily bonded to the substrate 100 with the surface

modification layer 130. The bonding process produces a bond region between the carrier 150 and the substrate 100 that is characterized by an adhesion energy between about 50 mJ/m² and about 800 mJ/m². Consequently, a separation force for separating the carrier 150 from the substrate 100 exists as a result of the bonding process.

[0038] As further depicted in FIG. 1A, the method 300a employs a laser input 200 upon an outer portion 191a of the second primary surface 152 of the carrier 150 to produce a thermal- assisted mechanical stress in a portion of the bond region between the carrier 150 and the substrate 100. In most implementations of the method 300a, the laser input 200 is directed upon an outer portion 191 a in substantial proximity to one or more edges of the carrier 150. Preferably, the outer portion 191 a is located adjacent to or away from an outer portion of the substrate 150 that is removably coupled to a fixture 11 (e.g., a fixture 11 that is removably coupled to primary surface 152 of the substrate 150). In the case of the method 300a depicted in FIG. 1 A, the thermal-assisted mechanical stress can be in the form of shear stresses 116a in proximity to the outer edges of the substrate 100 and carrier 150. According to the method 300a, the laser input 200 can be conducted for a thermal input time sufficient to reduce the separation force that existed between the carrier and the substrate after these components were initially bonded with a surface modification layer 130. It should also be understood that the separation force between the carrier 150 and the substrate 100 existing after these components have been bonded with a surface modification layer 130 can further increase through additional thermal processing conducted on the substrate including, but not limited to, the development of optoelectronic device elements on the substrate 100. Consequently, the laser input 200 can be conducted for a thermal input time sufficient to reduce an initial separation force that exists after the carrier and the substrate have been bonded and, in certain aspects, reduce a separation force (i.e., a separation force that is greater than the initial separation force) that exists after the carrier and the substrate have been subjected to additional thermal processing after bonding and before the laser input 200 has been directed upon the carrier 150.

[0039] As shown in FIG. 1 A, the shear stresses 1 16a can, in certain implementations of the method 300a, produce a gap 1 15 in a portion of the bond region between the substrate 100 and carrier 150. This gap 115 effectively reduces the separation force for separating the carrier from the substrate. It should also be understood that the laser input 200 can also be conducted according to the method 300a, and other aspects of the disclosure, to reduce the separation force without any corresponding development of a gap, delamination, or other comparable feature.

[0040] In aspects of the method 300a depicted in FIG. 1 A, the laser input 200 directed upon the outer portion 191 a of the carrier 150 produces a thermal gradient within the carrier that results in some displacement of the carrier 150 relative to the substrate 100, resulting in a displaced carrier 150'. As the laser input 200 is directed upon the outer portion 191 a of the carrier 150, the carrier absorbs the laser input 200 as a function of its absorptivity at the operating wavelengths of the laser input 200. In some embodiments, only a thin layer of the carrier 150 (e.g., to a depth of about 5 to 50 microns) absorbs the laser input 200. During the short period in which the outer portion 191 a of the carrier 150 is absorbing the laser input 200, the surface temperature of the carrier 150 in the vicinity of the outer portion 191 a can exceed that of the unexposed regions of the carrier 150 and the substrate 100 by 100°C or higher. Consequently, the temperature gradient that results from the laser input 200 over a short duration can result in a displaced carrier 150', displaced relative to the substrate 100. This displacement can lead to shear stresses 1 16a that result in the development of a gap 1 15 between the displaced carrier 150' and the substrate 100.

[0041] According to the method 300a, the gap 115 produced by laser input 200 in the bond region between the substrate 100 and the carrier 150 advantageously reduces the force necessary to separate the substrate 100 from the carrier 150. Without wishing to be bound by theory, the laser input 200 according to the method 300a may produce micro- or nano-sized defects, or other like features, in the bond region between the substrate 100 and the carrier 150 that effectively reduce the separation force between these components. Consequently, lower separation forces are necessary to fully separate the substrate 100 from the carrier 150, leading to higher production yields and lower product costs. [0042] The substrate 100 employed in the method 300a, and the other aspects of the disclosure, has a silicon, glass, glass-ceramic or ceramic composition. In many

implementations of the disclosure, the substrate 100 has a non-zero thermal expansion coefficient given the emphasis in the disclosure on the development of thermal-assisted mechanical stresses. For implementations in which the laser input 200 is directed upon the substrate 100, the composition of the substrate should be selected with a sufficient absorptivity in the wavelength range of the laser employed to produce the laser input 200; Corning® Willow® glass is one such implementation that can be processed according to the methods of the disclosure, including method 300a. The substrate 100 can also be fabricated from various suitable glass materials, including silicate glass, a boro-silicate glass, an alumino-boro-silicate glass, or a soda-lime-silicate glass. These glass compositions include alkali-free and alkali-containing glass compositions. In other preferred implementations, the substrate 100 is in the form of a wafer having a silicon (e.g., low temperature polysilicon (LTPS), high temperature polysilicon (HTPS), amorphous silicon (a-Si), etc.) or other semiconductor material composition (e.g., GaAs). Still further, the substrate 100 can be fabricated in the form of an interposer (e.g., as commonly understood in the electronic device industry) having a plurality of holes extending into or through its thickness. Moreover, the substrate 100 can be any suitable size, for example, Genl (300x400 mm), Gen2

(360x465mm), Gen3, Gen4, Gen5 (1100x1300 mm), Gen6, Gen7, Gen8 (2200x2500 mm), or Genl O.

[0043] In certain preferred implementations, the substrate 100 is in the form of a flexible substrate having a glass composition and a thickness of 300 μιτι or less, for example 300 μιτι, 275 μηι, 250 μιη, 225 μιη, 200 μητ, 175 μητ, 150 μιη, 125 μιη, 100 μιη, 75 μιη, 50 μητ, 25 μιτι, 20 μιτι, 15 μιτι, or 10 μιτι. It should also be understood that the substrate 100 can possess one or more edges (e.g., a short edge substantially parallel to the thickness direction) between its primary surfaces. The edge or edges can be present throughout the entire periphery of the substrate 100 or a portion of its periphery. As depicted in FIG. 1 A, the edges of the substrate 100 are square with its primary surfaces, but the edges need not have a square shape.

Alternatively, the edge or edges can be radiused, rounded (asymmetrically or symmetrically), or chamfered (asymmetrically or symmetrically).

[0044] The carrier 150 employed in the method 300a, and other aspects of the disclosure, can also possess a silicon, glass, glass-ceramic or ceramic composition. As such, the carrier 150 can be fabricated from various suitable glass materials, including silicate glass, a boro- silicate glass, an alumino-boro-silicate glass, or a soda-lime-silicate glass. These glass compositions include alkali-free and alkali-containing glass compositions. In many implementations of the disclosure, the carrier 150 is also selected with a composition having a non-zero thermal expansion coefficient. For implementations in which the laser input 200 is directed upon the carrier 150 (e.g., as depicted in FIG. 1A), the composition of the carrier should be selected with a sufficient absorptivity in the wavelength range of the laser employed to produce the laser input 200.

[0045] In certain preferred implementations, the carrier 150 is in the form of a rigid or semi-rigid substrate having a thickness of about 200 μιτι to about 1 mm, for example 200 μιτι, 250 μιη, 300 μιη, 350 μιη, 400 μιη, 450 μιη, 500 μιη, 550 μιη, 600 μιη, 650 μιη, 700 μιη, 750 μιη, 800 μιη, 850 μιη, 900 μιη, 950 μιη, or 1000 μιη. Corning® Eagle XG® glass is one such implementation of the carrier 150 that can be processed according to the methods of the disclosure, including method 300a. Moreover, the carrier 150 can be any suitable size, for example, Genl (300x400 mm), Gen2 (360x465mm), Gen3, Gen4, Gen5 (1100x1300 mm), Gen6, Gen7, Gen8 (2200x2500 mm), or GenlO.

[0046] In general, the dimensions and shape of the substrate 100 and carrier 150 are matched. As such, the edges of the substrate 100 and carrier 150 may be coincident (i.e., even or aligned) at a portion or the entirety of the periphery of the substrate 100 and carrier 150. In this case, the substrate 100 and carrier 150 will be the same or substantially the same size (e.g., Gen5). Alternatively, the carrier 150 can be larger than the substrate 100. In these implementations, an offset can exist between the carrier 150 and the substrate 100 at a portion or the entirety of their periphery. For example, such an offset can be in a direction substantially parallel to the primary surfaces of the carrier 150 and the substrate 100. An offset of 3 mm or less, for example, can be introduced between the carrier 150 and the substrate 100 to prevent deposition onto the carrier 150 of material that cannot be easily removed that may be associated with the processes for preparation of electronic components on the substrate 100. If the offset is too large, then materials associated with such electronic component processing on the substrate 100 can be deposited on the carrier 150, thus preventing reuse of this component.

[0047] The surface modification layer 130 is employed in the method 300a, and in other aspects of the disclosure, to bond the substrate 100 to the carrier 150, resulting in an adhesions energy between about 50 and 800 mJ/m². Various surface modification layers that can be employed as a surface modification layer 130 according to the methods and apparatus of the disclosure are detailed in U.S. Patent Application Publication Nos. 2014/0165654 and 2014/0170378, both published on June 19, 2014 (US '654 and US '378). Likewise, the surface modification layer can include a silicone material as detailed in EP2025650 or a temporary bonding agent as detailed in KR2013044774. Salient portions of US '654 and US '378 associated with such surface modification layers are hereby incorporated by reference in their entirety within this disclosure.

[0048] In some implementations, the surface modification layers 130 should be developed with a sufficient adhesion energy and temperature resistance to ensure that the substrate 100 and carrier 150 do not separate from the force of gravity (or other limited forces) during the processing and handling associated with the development of electronic device components (e.g., TFT arrays, optoelectronic device elements, etc.) upon the substrates. Example surface modification layers 130 include but are not limited to hexamethyldisilazane (HMDS), a plasma-polymerized fluoropolymer, and an aromatic silane, as further detailed in the US '654 publication. Alternatively to a surface modification layer 130, other bonding materials may be used to temporarily hold the substrate 100 and the carrier 150 together, whereupon the de- bonding initiation techniques of the present disclosure will also be useful to facilitate separating the substrate 100 and the carrier 150.

[0049] In preferred implementations, the surface modification layer 130 is employed in the method 300a such that the bond between the substrate 100 and the carrier 150 exhibits an adhesion energy between about 300 mJ/m² and 800 mJ/m². As such, the bonding step according to the method 300a can be conducted to define a bond region between the substrate 100 and the carrier 150 having an adhesion energy between about 300 mJ/m² and 800 mJ/m². In some aspects, the bond region and surface modification layer 130 may exhibit an adhesion energy between about 300 mJ/m² and 500 mJ/m². Still further, certain implementations of the method 300a (and the other methods outlined in the disclosure) can be employed to produce a reduction in the separation force between the carrier and the substrate for situations in which an adhesion energy between the substrate 100 and the carrier 150 exceeds 800 mJ/m², up to adhesion energies as high as about 1500 mJ/m².

[0050] As depicted in FIG. 1 A, the method 300a can employ various lasers to produce the laser input 200. Preferably, the laser should be selected with a wavelength (or wavelength range) to control the desired temperature gradient in the outer portion of the substrate 100 or carrier 150 (e.g., outer portion 191 a) subjected to the laser input 200. In particular, the laser and its associated wavelength should be selected based on the absorptivity of the material selected for the substrate 100 or the carrier 150 that will be irradiated with the laser according to the method 300a. For carriers and substrates having a silicate glass composition, a laser with a wavelength longer than 3 μηι should be sufficient to generate the thermal-assisted mechanical stresses in the bond region between the substrate 100 and the carrier 150 to reduce the separation force according to the disclosure. In preferred implementations, the wavelength of the laser should be longer than 5 μιτι and, even more preferably, longer than 8 μιτι. For example, a quantum-cascaded laser can provide a wide range of wavelengths that range from 4 μιτι to 12 μιτι. As another example, conventional CO2 lasers can provide wavelengths that range from 9 μιτι to about 10.6 μιτι with output power on the order of tens of kilowatts.

[0051] According to the method 300a, the fixture 11 (see FIG. 1 A) or a combination of fixtures 11 can comprise one or more vacuum fixtures, whether removably applied or otherwise coupled to one or both of the substrate 100 and carrier 150. The fixture 11 or combination of fixtures 11 can be removably coupled to the substrate 100 and/or the carrier 150 with a configuration to aid or otherwise control the thermal input 200 as it impinges on the outer portion 191 a to develop the shear stresses 116a. For example, the coupling forces between the fixture or fixtures 11 and the substrate 100 and/or carrier 150 can be adjusted to influence the shear stresses 116a developed by virtue of the thermal input 200. For example: (1) there may be no coupling forces between the fixture and the substrate 100/carrier 150, i.e., the substrate 100/carrier 150 may simply be set on the fixture 11 as an object on a table, resting there by the force of gravity; (2) the fixture may simply couple the substrate

100/carrier 150, as by application of vacuum; or (3) the fixtures may be used to couple with the substrate 100/carrier 150 (as by application of vacuum) and also apply a loading force (mechanical pulling force) to the substrate 100 and/or carrier 150 to assist with initiation, as described below. Similarly, the location of the fixture or fixtures 11, removably coupled to the substrate 100 and/or carrier 150, can also be controlled relative to the outer portion 191 a to influence the shear stresses 116a. Still further, mechanical movement of the fixtures 11 may be controlled during the laser initiation to assist the initiation by providing a mechanical pulling force tending to separate the substrate 100 from the carrier 150. When using a mechanical assisting force during the laser initiation, the direction and magnitude of the force can be controlled, for example, a force of about 1.2 pounds force (about 5.34 N) applied at the corner and initially normal to the plane of the substrate 100 (but remaining its direction as the substrate 100 is peeled from the carrier) may be used to produce a deflection of about 500 microns in the substrate/carrier pair, wherein the deflection is measured in relation to the starting point of the surface of the carrier/substrate pair at which the thermal input is applied. For example, as shown in FIG 1 A, deflection would be measured by the distance between the initial position of surface 152 (before the load is applied) and the position of surface 152 after the load has been applied. The loading and deflection provide a force that assists with initiation. According to one example, a 500 micron deflection was beneficial in initiating separation between a 0.5 mm thick carrier and a 0.1 mm thick substrate. According to another example, a 350 micron deflection was beneficial in initiating separation between a 0.7 mm thick carrier and a 0.1 mm thick substrate. In general, the amount of force and deflection that are beneficial will depend upon the thickness of the substrate and/or carrier, and may be limited by the edge strength of the substrate and/or carrier.

[0052] It should also be understood that various alternatives for fixture 11 are suitable according to the methods and apparatus of the disclosure. For example, a layer of adhesive material may be applied between substrate 100 and a fixture 11 to ensure sufficient adhesion between the fixture and the substrate 100 during the de-bonding process according to method 300a. Suitable adhesive materials for this purpose include but are not limited to epoxy, polymer, grease and rubber adhesives, combinations thereof, including in combination with fixtures having the ability to provide some vacuum force between the fixture 11 and the substrate 100 (or carrier 150).

[0053] In certain aspects of the method 300a, a thermal input other than the laser input 200 can be generated by another heat source (e.g., a microwave heating device), provided that such a heat source imparts high thermal energies within a small outer region of the carrier 150 (e.g., 500 to 3000 mm²) and/or the substrate 100 for a relatively short duration (e.g., less than 10 seconds). It should therefore be understood that heat sources that provide uniform thermal inputs over the entirety of the combination of the carrier 150 and substrate 100 over durations exceeding tens of minutes are not generally contemplated by the disclosure, as such heat inputs will not produce the necessary thermal gradients in the carrier and/or substrate to produce thermal-assisted mechanical stresses sufficient to reduce the separation force between these components.

[0054] In preferred implementations, the duration of the exposure of the laser input 200 to the substrate 100 or carrier 150 (e.g., outer portion 191 a) can be limited to 2 seconds or less, for example about 1 second - i.e., when the thermal input is provided by a laser source. It should also be understood that aspects of the method 300a, and the other methods detailed in this disclosure, can also include a vibrational energy component, to supplement the laser input 200 or other thermal input, directed against an outer portion of the substrate 100 or carrier 150. That is, these components may be appropriately fixtured or otherwise configured such that vibrational energy (e.g. , from an ultrasonic or megasonic energy source) is preferentially applied to the bond region between the substrate 100 and the carrier 150 to assist in the reduction of the separation force necessary to peel apart the substrate 100 and the carrier 150 that were temporarily bonded with a surface modification layer 130.

[0055] In certain aspects of the method 300a, and other aspects of the disclosure, it is important to control the laser input 200 such that temperatures in proximity to a surface of the substrate 100 containing optoelectronic or other electronic device components are held below any threshold temperature that may cause damage or failure of these components. In some aspects of the method 300a, temperature sensors with digital outputs and/or temperature dots as understood in the operative field can be employed in proximity to such surfaces of the substrate 100 for this purpose. In general, the laser input 200 should be controlled such that the temperatures in proximity to any such optoelectronic or other electronic device components do not exceed 250°C. Preferably, the thermal input duration and/or the associated energy of the laser input 200 should be limited such that these temperatures do not exceed 200°C or, even more preferably, remain below 150°C, for example below about 140°C, for example about 138°C.

[0056] According to the method 300a, a step of separating the carrier 150 from the substrate 100 can be conducted after the step of directing the laser input 200 upon an outer portion of the substrate 100 or carrier 150. For these implementations, the separating step may involve the application of a separation force to one or both of the substrate 100 and the carrier 150 that is lower than that which would have been necessary to separate the substrate and carrier as they existed immediately after being bonded with a surface modification layer 130. According to one embodiment, the laser initiation separates the substrate 100 from the carrier 150 at a corner thereof. The initially separated area may then be expanded across one edge of the substrate 100 / carrier 150 interface. According to one embodiment, the initially separated area may be expanded by use of a fluid nozzle. A fluid nozzle may be pointed at the initially separated area, at the interface between the carrier 150 and substrate 100. The nozzle may be disposed perpendicularly to the edge of the carrier 150 / substrate 100 pair, or may be skew thereto. Fluid is then issued through the nozzle (for example, air at 55-60 pounds per square inch, and at a flow rate of 22-26 cubic feet per hour, on a line

perpendicular to the edge, and at a position wherein there is about a 100 to 200 micron gap between the substrate and carrier) toward the interface as the nozzle is translated along the edge of the carrier 150 / substrate 100 pair to propagate the initially separated area to the extent of the edge. In order to minimize disturbance to devices built on the substrate, the fluid may be gas, for example air or nitrogen. The pressure and flow rate of the fluid will depend, at least in part, on the thicknesses of the sheets being separated.

[0057] Then, to peel the substrate 100 and carrier 150 completely apart, a fixture 11 , or fixtures 1 1 , removably coupled to the substrate 100 and/or carrier 150 can be employed to separate the carrier from the substrate after the step of directing the laser input 200 upon an outer portion of the substrate 100 or carrier 150 (e.g., outer portion 191 a), or after both the laser initiated separation and propagation of the initially separated area as explained above. In one exemplary configuration, a fixture 11 coupled to the substrate 100 can hold the substrate 100 in place while a second fixture 11 removably coupled to the carrier 150 can be moved relative to the substrate 100 (e.g., peeled back) to separate the carrier 150 from the substrate 100.

[0058] In a further embodiment, a method 300b for processing a substrate is depicted in FIG. IB. It should be understood that like-numbered elements in the figures of the disclosure have the same or similar constructions and compositions. For example, FIG. IB depicts a substrate 100 that is bonded to a carrier 150 with a surface modification layer 130. A fixture 1 1 is removably attached to the substrate 100 as shown. One or more fixtures 11 can be removably attached to the carrier 150 during the method 300b. The carrier 150 has a second primary surface 152, a first primary surface 154 and one or more edges 156 as shown in FIG. IB. Further, the first primary surface 154 of the carrier 150 is bonded to the substrate 100 with the surface modification layer 130. The bonding process produces a bond region between the carrier 150 and the substrate 100 that is characterized by an adhesion energy between about 50 mJ/m² and about 800 mJ/m². Consequently, a separation force for separating the carrier 150 from the substrate 100 exists as a result of the bonding process.

[0059] As further depicted in FIG. IB, the method 300b employs a laser input 200 upon an outer portion 191b of an edge 156 of the carrier 150 to produce a thermal-assisted mechanical stress in a portion of the bond region between the carrier 150 and the substrate 100. In the case of the method 300b depicted in FIG. IB, the thermal-assisted mechanical stress can be in the form of tensile stresses 1 16b in proximity to the outer edges of the substrate 100 and carrier 150 (e.g., edges 156). According to the method 300b, the laser input 200 can be conducted for a thermal input time sufficient to reduce the separation force necessary to peel apart the carrier and the substrate that were temporarily bonded with a surface modification layer 130. As shown in FIG. IB, the tensile stresses 116b can, in certain implementations of the method 300b, produce a gap 115 in a portion of the bond region between the substrate 100 and carrier 150. This gap 115 effectively reduces the separation force for separating the carrier from the substrate. It should also be understood that the laser input 200 can also be conducted according to the method 300b, and other aspects of the disclosure, to reduce the separation force without any corresponding development of a gap, a delamination, or other comparable feature.

[0060] In aspects of the method 300b depicted in FIG. IB, the laser input 200 directed upon the outer portion 191b of an edge 156 of the carrier 150 produces a thermal gradient within the carrier that results in some displacement of the carrier 150 relative to the substrate 100, resulting in a displaced carrier 150'. As the laser input 200 is directed upon the outer portion 191b of an edge 156 the carrier 150, the carrier absorbs the laser input 200 as a function of its absorptivity at the operating wavelengths of the laser input 200. Preferably, the width of the laser input 200 (e.g., laser beam diameter) should be of a dimension smaller than the width of the irradiated edge 156 (e.g., the thickness of the carrier 150). The beam size of the laser input 200 can be as small as tens of microns ensuring that only a narrow strip of the edge 156 is exposed or otherwise irradiated by the laser input 200. Consequently, the relatively small outer portion 191b of the edge 156 can expand relative to the substrate 100, resulting in a displaced carrier 150'. This displacement can generate tensile stresses 116b, which can lead to the development of a gap 115 between the displaced carrier 150' and the substrate 100. As with method 300a, fixtures 11 may be used to assist the laser in providing an initiation. The fixture 11 or combination of fixtures 11 can be removably coupled to the substrate 100 and/or the carrier 150 with a configuration to aid or otherwise control the thermal input 200 as it impinges on the outer portion 191b to develop the tensile stresses 1 16b. For example, the coupling forces between the fixture or fixtures 1 1 and the substrate 100 and/or carrier 150 can be adjusted to influence the tensile stresses 1 16b developed by virtue of the thermal input 200. For example: (1 ) there may be no coupling forces between the fixture and the substrate 100/carrier 150, i.e., the substrate 100/carrier 150 may simply be set on the fixture 1 1 as an obj ect on a table, resting there by the force of gravity; (2) the fixture may simply couple the substrate 100/carrier 150, as by application of vacuum; or (3) the fixtures may be used to couple with the substrate 100/carrier 150 (as by application of vacuum) and also apply a loading force (mechanical pulling force) to the substrate 100 and/or carrier 150 to assist with initiation, as described below. Similarly, the location of the fixture or fixtures 1 1, removably coupled to the substrate 100 and/or carrier 150, can also be controlled relative to the outer portion 191b to influence the tensile stresses 1 16b. Still further, mechanical movement of the fixtures 11 may be controlled during the laser initiation to assist the initiation by providing a mechanical pulling force tending to separate the substrate 100 from the carrier 150. When using a mechanical assisting force during the laser initiation, the direction and magnitude of the force can be controlled, for example, a force of about 1.2 pounds force (about 5.34 N) applied at the corner and initially normal to the plane of the substrate 100 (but remaining its direction as the substrate 100 is peeled from the carrier) may be used to produce a deflection of about 500 microns in the substrate/carrier pair, wherein the deflection is measured in relation to the starting point of the most outward surface of the carrier/substrate pair of the sheet to which the thermal input is applied. For example, as shown in FIG IB, deflection would be measured by the distance between the initial position of surface 152 (before the load is applied) and the position of surface 152 after the load has been applied. The loading and deflection provide a force that assists with initiation. According to one example, a 500 micron deflection was beneficial in initiating separation between a 0.5 mm thick carrier and a 0.1 mm thick substrate. According to another example, a 350 micron deflection was beneficial in initiating separation between a 0.7 mm thick carrier and a 0.1 mm thick substrate. In general, the amount of force and deflection that are beneficial will depend upon the thickness of the substrate and/or carrier, and may be limited by the edge strength of the substrate and/or carrier. [0061] According to the method 300b, the gap 1 15 produced by laser input 200 in the bond region between the substrate 100 and the carrier 150 advantageously reduces the force necessary to separate the substrate 100 from the carrier 150. It should also be understood that the laser input 200 according to the method 300b may produce micro- or nano-sized defects, or other like features, in the bond region between the substrate 100 and the carrier 150 that effectively reduce the separation force between these components. Consequently, lower separation forces are necessary to fully separate the substrate 100 from the carrier 150, leading to higher production yields and lower product costs.

[0062] As with method 300a, a step of separating the carrier 150 from the substrate 100 can be conducted as part of the method 300b after the step of directing the laser input 200 upon an outer portion of the substrate 100 or carrier 150. For these implementations, the separating step may involve the application of a separation force to one or both of the substrate 100 and the carrier 150 that is lower than that which would have been necessary to separate the substrate and carrier as they existed immediately after being bonded with a surface modification layer 130. According to one embodiment, the laser initiation separates the substrate 100 from the carrier 150 at a corner thereof. The initially separated area may then be expanded across one edge of the substrate 100 / carrier 150 interface. According to one embodiment, the initially separated area may be expanded by use of a fluid nozzle. A fluid nozzle may be pointed at the initially separated area, at the interface between the carrier 150 and substrate 100. The nozzle may be disposed perpendicularly to the edge of the carrier 150 / substrate 100 pair, or may be skew thereto. Fluid is then issued through the nozzle (for example, air at 55-60 pounds per square inch, and at a flow rate of 22-26 cubic feet per hour, on a line perpendicular to the edge, and at a position wherein there is about a 100 to 200 micron gap between the substrate and carrier) toward the interface as the nozzle is translated along the edge of the carrier 150 / substrate 100 pair to propagate the initially separated area to the extent of the edge. In order to minimize disturbance to devices built on the substrate, the fluid may be gas, for example air or nitrogen. The pressure and flow rate of the fluid will depend, at least in part, on the thicknesses of the sheets being separated.

[0063] Then, to peel the substrate 100 and carrier 150 completely apart, a fixture 11 , or fixtures 1 1 , removably coupled to the substrate 100 and/or carrier 150 can be employed to separate the carrier from the substrate after the step of directing the laser input 200 upon an outer portion of the substrate 100 or carrier 150 (e.g., outer portion 191b), or after both the laser initiated separation and propagation of the initially separated area as explained above. In one exemplary configuration, a fixture 11 coupled to the carrier 150 can hold the carrier 150 in place (see, e.g., FIG. I B) while a second fixture 11 removably coupled to the substrate 100 can be moved relative to the carrier 150 (e.g., peeled back) to separate the substrate 100 from the carrier 150.

[0064] Variations can be made to the methods 300a and 300b that are depicted in FIGS. 1A and IB, consistent with the principles of the disclosure. In particular, a laser input 200 or other suitable thermal input can be directed to one or more outer portions of the substrate 100 and/or carrier 150 to effect a reduction in the separation force between the carrier and substrate. For example, a fixture 11 can be attached to the carrier 150 and an outer portion of the substrate 100 (e.g. , on a primary surface of the substrate 100 in proximity to an edge, an edge of the substrate, etc.) can be subjected to direct exposure to a laser input 200 or other sufficient thermal input consistent with the principles of the disclosure. That is, the method, fixturing and various outer portions of the substrate 100 and/or carrier 150 can be selected and configured to produce thermal-assisted stresses (e.g., shear and/or tensile stresses) in the vicinity of the bond region between the carrier 150 and the substrate 100 to reduce the separation force that existed after the carrier initially had been temporarily bonded to the substrate with a surface modification layer (e.g. surface modification layer 130). Various considerations should be taken into account in directing the thermal input to one or more outer portions of the substrate 100 and/or carrier 150 to reduce the separation force. These considerations include but are not necessarily limited to the absorptivity of the component directly subjected to the thermal input; the wavelength or wavelength range of the heat source providing the thermal input; the coefficients of thermal expansion of the substrate, carrier and surface modification layer; the surface area of the irradiated outer portion or portions of the carrier and/or substrate; and the duration of the heat input.

[0065] Referring to FIG. 2, an exemplary method 300c is depicted for processing a pair of substrates sandwiching a plurality of electronic components and temporarily bonded to a respective pair of carriers according to the disclosure. In particular, the method 300c can be employed with a pair of flexible glass substrates 100a and 100b sandwiching a plurality of opto-electronic components 160. A pair of carriers 150a and 150b having a glass composition comparable to the flexible glass substrates 100a and 100b are temporarily bonded to the substrates 100a and 100b by a surface modification layer (e.g. , surface modification layer 130). The carriers 150a and 150b assist in maintaining a flat orientation for the flexible glass substrates 100a and 100b during development of the opto-electronic components 160 according to conventional processes understood in the field. For example, the opto-electronic components 160 can include various electronic device elements suitable for production of a thin film transistor-liquid crystal display device (TFT-LCD) upon the flexible glass substrates 100a and 100b.

[0066] As also depicted in FIG. 2, the method 300c employs fixtures 11 a and l ib to hold portions of the respective carriers 150a and 150b. In particular, a substantial portion of the carrier 150a is temporarily held in place by fixture 1 la (e.g., a vacuum fixture), leaving exposed a comer portion 191c of the carrier 150a. The fixture 1 la provides sufficient force to maintain contact between the fixture 11a and the substantial outer portion of the carrier 150a (except for the exposed portion 191 c). Fixture 11 a is also removably attached to this substantial outer portion of the carrier 150a. As also shown in FIG. 2, a fixture 1 lb can be configured in removable contact with a corner of the carrier 150b that generally opposes the exposed portion 191c of the carrier 150a Further, in some implementations, the fixture 1 lb can be configured with a mechanical apparatus that allows for a variable pulling force at the corner of the carrier 150b in contact with the fixture l ib. As with method 300a, fixtures 11a, b may be used to assist the laser in providing an initiation. The fixtures 1 la, b can be removably coupled to the substrate 100 and/or the carrier 150 with a configuration to aid or otherwise control the thermal input 200 as it impinges on the outer portion 191b to develop the separation stresses. For example, the coupling forces between the fixture or fixtures 11 and the substrate 100 and/or carrier 150 can be adjusted to influence the stresses developed by virtue of the thermal input 200. For example: (1) there may be no coupling forces between the fixture and the substrate 100/carrier 150, i.e., the substrate 100/carrier 150 may simply be set on the fixture 11 as an object on a table, resting there by the force of gravity; (2) the fixture may simply couple the substrate 100/carrier 150, as by application of vacuum; or (3) the fixtures may be used to couple with the substrate 100/carrier 150 (as by application of vacuum) and also apply a loading force (mechanical pulling force) to the substrate 100 and/or carrier 150 to assist with initiation, as described below. Similarly, the location of the fixture or fixtures 1 la, b, removably coupled to the carriers 150a, b, can also be controlled relative to the outer portion 191b to influence the laser-induced stresses. Still further, mechanical movement of the fixtures 11 a, b may be controlled during the laser initiation to assist the initiation by providing a mechanical pulling force tending to separate the a carrier 150a, b from its corresponding substrate 100a, b. When using a mechanical assisting force during the laser initiation, the direction and magnitude of the force can be controlled, for example, a force of about 1.2 pounds force (about 5.34 N) applied at the corner and initially normal to the plane of the substrate 100 (but remaining its direction as the substrate 100 is peeled from the carrier) may be used to produce a deflection of about 500 microns in the substrate/carrier pair, wherein the deflection is measured in relation to the starting point of the surface of the carrier/substrate pair at which the thermal input is applied. For example, as shown in FIG 2, deflection would be measured by the distance between the initial position of the top surface of carrier 150a (before the load is applied) and the position of that same surface after the load has been applied. The loading and deflection provide a force that assists with initiation. According to one example, a 500 micron deflection was beneficial in initiating separation between a 0.5 mm thick carrier and a 0.1 mm thick substrate that were part of a stack having, in the following order, a 0.5 mm thick carrier, a 0.1 mm thick substrate, an epoxy, a 0.1 mm thick substrate, and a 0.5 mm thick carrier. According to another example, a 350 micron deflection was beneficial in initiating separation between a 0.7 mm thick carrier and a 0.1 mm thick substrate that were part of a stack having, in the following order, a 0.7 mm thick carrier, a 0.1 mm thick substrate, an epoxy, a 0.1 mm thick substrate, and a 0.7 mm thick carrier. In general, the amount of force and deflection that are beneficial will depend upon the thickness of the substrate and/or carrier, and may be limited by the edge strength of the substrate and/or carrier.

[0067] With the configuration depicted in FIG. 2, the method 300c can be used to reduce the separation force from that which existed between the carrier 150a and the flexible glass substrate 100a immediately after they were temporarily bonded. In particular, a laser input 200 is directed upon the exposed portion 191 c of the carrier 150a. In certain aspects, the laser input 200 can be directed over the portion 191c, in which the portion 191 c is configured in a triangular shape having a height 192 and base 193 (see FIG. 2 A). It should be understood that the method 300c can be employed effectively with an exposed portion 191c having any of a variety of shapes, at least partly influenced by the geometry of the carrier 150a and flexible substrate 100a. For example, a portion 191c having a triangular shape may be varied in shape (e.g., a right triangle, an isosceles triangle, etc.) depending on the overall length and width relationship of the flexible substrate 100a and the carrier 150a. According to one embodiment a right triangle, having legs each of about 40mm and its right angle generally aligned with the corner of the carrier 150a, b, was successfully used to initiate separation over a corresponding triangular region between the carrier 150 and the substrate 100. Most times, when using a loading force to assist the laser initiation, the separation will occur over an area that is at least equal to that over which the laser input has been applied. In general, it is beneficial for the area over which the thermal input is applied to avoid the area on which the electronic devices are disposed, or at least minimize such overlap to the extent so that the heat applied to the electronic devices does not destroy them. Accordingly, in general, a smaller area of irradiation is advantageous in some circumstances.

[0068] According to the method 300c, the laser input 200 should be directed upon the exposed portion 191 c of the carrier 150a for several seconds or less to ensure that a sufficient temperature gradient is developed in the thickness of the carrier 150a, without significant thermal diffusion to the opposing carrier 150b and/or substrate 100b. As the exposed portion 191 c is irradiated by the laser input 200, the carrier 150a exhibits some displacement relative to the substrates 100a and 100b, and the carrier 150b. Further, the carrier 150b is held in place by fixture l ib. Consequently, tensile stresses are developed in the bond region between the flexible glass substrate 100a and the carrier 150a, e.g., in the vicinity of the surface modification layer 130 (not shown in FIG. 2). These tensile stresses are sufficient to reduce the separation force between the carrier 150a and the flexible glass substrate 100a, facilitating a subsequent step of separating the carrier 150a from the flexible glass substrate 100a. It also believed that the exposed portion 191 c, laser input 200, fixtures 11 a and l ib and material properties (e.g., coefficient of thermal expansion) of the carriers 150a, 150b and flexible glass substrates 100a, 100b can be tailored according to the method 300c alone, or in combination, to generate sufficient tensile stresses in the bond region between the carrier 150b and flexible substrate 100b to reduce the separation force between the carrier 150b and the substrate 100b.

[0069] According to the method 300c (and the prior-described methods 300a and 300b), laser-induced displacement of the substrate (e.g., flexible glass substrate 100a) and/or the carrier (e.g., carrier 150a) subjected to the thermal input plays an important role in achieving a reduction in the separation force between these components after they have been bonded with a surface modification layer. To ensure sufficient relative displacement of the irradiated substrate or carrier according to the method 300c depicted in FIG. 2, the laser power, size of the exposed outer portion 191 c, and the duration of the exposure of the exposed outer portion 191 c to the laser input 200 should be well-controlled. For example, the laser power and duration of the exposure can be controlled to deliver an appropriate thermal gradient across the carrier thickness, which thermal gradient causes a localized deformation of the carrier that leads to initial separation between the carrier and substrate.

[0070] In certain implementations of the method 300c, the fixtures 11 a and l ib can be reversed such they are removably attached to carriers 150b and 150a, respectively. As such, an exposed portion 191 c will be present on the carrier 150b in this configuration. A laser input 200 can then be directed upon the exposed portion 191 c of the carrier 150b to develop tensile stresses in the bond region between the flexible glass substrate 100b and the carrier 150b to reduce the separation force between the substrate 100b and the carrier 150b, e.g., according to the foregoing principles of method 300c associated with reducing the separation force between the substrate 100a and the carrier 150a.

[0071] Once the separation force between the pairs of substrates 100a, 100b and the respective carriers 150a, 150b has been reduced according to the method 300c, an optional step of separating the carriers 150a, 150b from the substrates 100a, 100b can be conducted. For these implementations, the separating step may involve the application of a separation force to one or both of the substrates 100a, 100b and the respective carriers 150a, 150b that is lower than that which would have been necessary to separate these components as they existed immediately after being bonded with a surface modification layer 130. According to one embodiment, the laser initiation separates the substrate 100 from the carrier 150 at a corner thereof. The initially separated area may then be expanded across one edge of the substrate 100 / carrier 150 interface. According to one embodiment, the initially separated area may be expanded by use of a fluid nozzle. A fluid nozzle may be pointed at the initially separated area, at the interface between the carrier 150 and substrate 100. The nozzle may be disposed perpendicularly to the edge of the carrier 150 / substrate 100 pair, or may be skew thereto. Fluid is then issued through the nozzle (for example, air at 55-60 pounds per square inch, and at a flow rate of 22-26 cubic feet per hour, on a line perpendicular to the edge, and at a position wherein there is about a 100 to 200 micron gap between the substrate and carrier) toward the interface as the nozzle is translated along the edge of the carrier 150 / substrate 100 pair to propagate the initially separated area to the extent of the edge. In order to minimize disturbance to devices built on the substrate, the fluid may be gas, for example air or nitrogen. The pressure and flow rate of the fluid will depend, at least in part, on the thicknesses of the sheets being separated.

[0072] Then, to peel the substrate 100 and carrier 150 completely apart, the fixtures 11a and l ib, removably coupled to the carriers 150a, 150b, can be employed to separate one or both of the carriers 150a, 150b from the substrates 100a, 100b after the step of directing the laser input 200 upon an outer portion of a substrate 100 or carrier 150, or after both the laser initiated separation and propagation of the initially separated area as explained above. For example, fixture 1 la, coupled to the carrier 150a, can hold the carrier 150a in place while fixture l ib, removably coupled to the carrier 150b, can be moved relative to the carrier 150a and substrates 100a, 100b (e.g., peeled back) to separate the carrier 150b from the substrate 100b. The fixtures 11 a and l ib can then be reversed such that fixture 11a is removably attached to substrate 100b (i.e., carrier 150b has now been removed) and fixture 1 lb is removably attached to carrier 150a. Fixture l ib can then be moved relative to the substrate 100b such that the carrier 150a is separated from the substrate 100a while fixture 1 la is held in place, attached to substrate 100b.

[0073] In the exemplary outer portion 191c shown in FIG. 2A, the triangular shape can be achieved by rapid scanning of a laser beam derived from a CO2 laser having a beam diameter of 3.5 mm according to the following scanning parameters: a stepping distance of 0.125 mm; a scanning speed of 7500 mm/s; and a scanning time of approximately 1.77 seconds. The CO2 laser employed to generate the shape of the exposed portion 191c shown in FIG. 2A operated at 40 kHz, has a 60% duty ratio, and an approximate 600W output. In some aspects, it has been found to be advantageous to start the laser scan at the corner of the triangle (particularly the corner of the triangle corresponding to the corner of the carrier 150a) and move toward a side, whereby the laser covers longer and longer distances across the triangle.

[0074] In one example, the method 300c and the arrangement depicted in FIG. 2 was employed with Corning® Willow® glass panels, each having a thickness of about 100 μιτι (i.e., the pair of panels having a total thickness of about 200 μιτι), as the flexible glass substrates 100a and 100b. A surface modification layer comprising a plasma-polymerized fluoropolymer was employed to bond the substrates 100a, 100b to the respective carriers 150a, 150b. The carriers 150a and 150b were fabricated from glass panels, each panel having a Corning® Eagle XG® composition and a thickness of about 0.5 mm (i.e., the pair of panels having a total thickness of about 1 mm). In addition, the fixture l ib was configured in a 1" x 1 " triangular shape with an approximate 73 kPa vacuum that produced a pulling force of about 550 grams on the carrier 150b. The foregoing laser scan parameters were employed to irradiate an outer exposed portion 191 c of the carrier 150a having a triangular shape (see FIG. 2A) with a laser input 200 for about 1.77 seconds. At least one sample subjected to the method 300c according to these parameters required a separation force on the order of about 2 N to fully separate a carrier 150a from a Willow® glass substrate 100a. In comparison, separation forces of 25 N were not sufficient to remove the carrier 150a from the Willow® glass substrate prior to the imposition of the method 300c.

[0075] According to a further aspect of the disclosure, a method 400a is depicted in FIG. 3 for processing a substrate 100 bonded to a carrier 150. The method 400a incorporates the elements of method 300a, along with further aspects related to apparatus for the detection of the relative deformation or displacement of the carrier 150 with regard to the substrate 100 during the step of directing a thermal input against an outer portion 191 a of the carrier 150. As depicted in FIG. 3, the carrier 150 is shown in a deformed or displaced state as a displaced carrier 150' during or after the step of directing a laser input 200 through beam optics 200a against the outer portion 191 a of the carrier.

[0076] In the configuration depicted in FIG. 3, a light source 245 produces an optical beam pattern 241 a that is directed against the outer portion 191a exposed to the laser input 200. The light source 245 can include beam shaping optical elements to produce a pattern 241 a consisting of straight lines having an equal spacing (see FIG. 4 A). The pattern 241 a is reflected from the exposed outer portion 191 a of the carrier 150 (not shown) and the displaced carrier 150' in the form of a reflected light pattern 241b (see FIG. 4B). A position detection device 240 receives the reflected light pattern 241b. As shown in FIG. 4B, the reflected light partem 241b will experience some dimensional changes relative to the pattern 241 a as the laser input 200 is directed against the outer portion 191 a. As such, the reflected beam pattern 241b carries information that can be correlated to displacement of the carrier 150 and analyzed by the position detection device 240 or a microprocessor element (not shown) coupled to the device 240.

[0077] According to the method 400a and the configuration depicted in FIGS. 3, 4A and 4B, the displacement information associated with the particular displacement of the displaced carrier 150' can be monitored in real time during the step of directing the laser input 200 against the outer portion 191a in a closed loop. The displacement information can then be utilized by a controller coupled to the laser (not shown) responsible for generating the laser input 200. In particular, various laser parameters (e.g., power levels, scanning duration, scanning area, etc.) can be adjusted as a function of displacement of the carrier 150 during the step of directing the laser input 200 against the outer portion 191a of the carrier 150. The closed loop arrangement depicted in FIG. 3 can thus be employed in the method 400a to reliably and repeatedly produce thermal-assisted mechanical stresses in the vicinity of the bond region between the substrate 100 and the carrier 150 to effect a controlled reduction in the separation force. For example, such a system depicted in FIG. 3 can be employed by a method comparable to method 400a in a manufacturing environment to account for dimensional tolerance of the substrate 100 and carrier 150, as bonded with a surface modification layer 130.

[0078] It should be emphasized that the above-described embodiments of the present invention, particularly any "preferred" embodiments, are merely possible examples of implementations, merely set forth for a clear understanding of various principles of the invention. Many variations and modifications may be made to the above-described embodiments of the invention without departing substantially from the spirit and various principles of the invention. All such modifications and variations are intended to be included herein within the scope of this disclosure and the present invention and protected by the following claims.

[0079] For example, the methods 300a and 300b and configurations of FIGS. 1A and IB generally depict exemplary arrangements of a substrate 100 bonded to a carrier 150 by a surface modification layer 130. Opto-electronic elements and other electronic device elements that have been formed on the substrate 100 are not depicted in FIGS. 1A and IB, but may be present between the substrate 100 and the fixture 11. Alternatively, fixture 11 may only be temporarily attached to portions of the substrate 100 not containing such electronic device components. As another alternative, the fixture 11 could be affixed to the carrier 150 and the laser input 200 can be directed upon an outer portion of the substrate not containing such device components. Accordingly, various configurations and arrangements of substrate-carrier pairs consistent with the principles taught in connection with the methods 300a and 300b are feasible within the provisions of this disclosure.

[0080] Additionally, for example, although fixture 1 la (other than at exposed outer portion 191c) was shown in FIG. 2 as being of substantially coincident area as the carrier 150a, such need not be the case. Instead, as with fixture l ib, the fixture 11 a may contact the carrier 150a over an area much smaller than the area of the carrier 150a.

[0081] Further, for example, although fixtures 11, 11 a, l ib were shown as having planar surfaces for engaging the substrates/carriers, such need not be the case. In some situations, it may be advantageous to have a curved surface on the fixture on the opposite side of the substrate/carrier as that from which the laser is applied. In such a situation, the curved surface of the fixture may be used to provide the above-described displacement to the carrier/substrate when coupled (as by vacuum) thereto.

[0082] Further, for example, although in FIG. 2 fixture 1 lb is shown as supporting the comer of carrier 150b undemeath exposed corner portion 191 c, instead fixture b could have a configuration similar to that of fixture 11a, wherein there is an exposed corner portion of carrier 150b that is similar in area to the exposed corner portion 191c of carrier 150a.

[0083] Still further, the particular configuration of substrates 100a, 100b, carriers 150a, 150b and fixtures 11a, l ib depicted in FIG. 2 in connection with describing the method 300c is exemplary. In one alternative configuration, a stack of alternating pairs of substrates 100a and carriers 150a can be configured within a pair of fixtures 11a and 1 lb as generally shown in FIG. 2. Each substrate lOOa-carrier 150a pair can be temporarily bonded with a moderate- strength adhesive in a process step subsequent to the step for bonding each substrate 100a to a respective carrier 150a with a surface modification layer 130. According to this

configuration, the method 300c can be employed to reduce the separation force associated with a first substrate lOOa-carrier 150a pair by subjecting an exposed outer portion 191 c of the carrier 150a in the first pair to the laser input 200. Once the separation force has been reduced for this pair, the carrier 150a can be separated from its respective substrate 100a by a peeling action from fixture 1 la. Next, the fixture 11 a can be applied to the carrier 150a corresponding to the next substrate lOOa-carrier 150a pair within the stack and the process repeated until all substrate-carrier pairs have been separated.

[0084] It is to be understood that various features disclosed in this specification and in the drawings can be used in any and all combinations. By way of non-limiting example the various features may be combined with one another as set forth in the following aspects.

[0085] According to a first aspect, a method of processing a substrate is provided that includes the steps: providing a carrier having first and second primary surfaces; providing a substrate having a silicon, glass, glass-ceramic or ceramic composition; bonding the substrate to the first primary surface of the carrier using a surface modification layer to define (i) a bond region between carrier and the substrate having an adhesion energy between about 50 and 800 mJ/m² and (ii) a separation force for separating the carrier and the substrate after the bonding step; and directing a thermal input to a portion of the second primary surface of the carrier to produce a thermal-assisted mechanical stress in a portion of the bond region.

Further, the directing step is conducted for a thermal input time sufficient to reduce the separation force.

[0086] According to a second aspect, a method of processing a substrate is provided that includes the steps: providing a carrier having first and second primary surfaces, and a plurality of edges; providing a substrate having a silicon, glass, glass-ceramic or ceramic composition; bonding the substrate to the first primary surface of the carrier using a surface modification layer to define (i) a bond region between carrier and the substrate having an adhesion energy between about 50 and 800 mJ/m² and (ii) a separating force for separating the carrier and the substrate after the bonding step; and directing a thermal input to a portion of one of the edges of the carrier to produce a thermal-assisted mechanical stress in a portion of the bond region. In addition, the directing step is conducted for a thermal input time sufficient to reduce the separation force.

[0087] According to a third aspect, a method of processing a substrate is provided that includes the steps: providing a carrier having first and second primary surfaces, and a plurality of edges; providing a substrate having a silicon, glass, glass-ceramic or ceramic composition; bonding the substrate to the first primary surface of the carrier using a surface modification layer to define (i) a bond region between carrier and the substrate having an adhesion energy between about 50 and 800 mJ/m² and (ii) a separating force for separating the carrier and the substrate after the bonding step; and directing a thermal input to an outer portion of the carrier or an outer portion of the substrate to produce a thermal-assisted mechanical stress in a portion of the bond region. Further, the directing step is conducted for a thermal input time sufficient to reduce the separation force.

[0088] According to a fourth aspect, there is provided the method of any one of aspects 1- 3, wherein the substrate is a flexible substrate having a glass composition and a thickness of 300 μιτι or less, and the carrier has a glass composition and a thickness from about 200 μιτι to about 1 mm. [0089] According to a fifth aspect, there is provided the method of any one of aspects 1 -

4, wherein the thermal input is provided by a laser.

[0090] According to a sixth aspect, there is provided the method of any one of aspects 1 -

5, wherein the thermal input time is about 2 seconds or less.

[0091] According to a seventh aspect, there is provided the method of any of one of aspects 1-6, wherein the substrate comprises one or more optoelectronic device elements.

[0092] According to an eighth aspect, there is provided the method of any one of aspects 1 -7, further comprising the step: separating the carrier from the substrate at a force greater than or equal to the separation force after the directing step has been completed.

[0093] According to a ninth aspect, there is provided the method of any one of aspects 1 -

8, wherein the bonding step is conducted to define a bond region having an adhesion energy between about 300 and 800 mJ/m².

[0094] According to a tenth aspect, there is provided the method of any one of aspects 1 -

9, wherein the directing step is conducted for a thermal input time sufficient to separate at least a portion of the carrier from the substrate in the portion of the bond region.

[0095] According to an eleventh aspect, there is provided the method of any one of aspects 1 -10, wherein the directing step further produces a displacement of a portion of the carrier relative to the substrate, the displacement being monitored to control the thermal input time.

[0096] According to a twelfth aspect, there is provided the method of any one of aspects 1 -1 1 , further comprising, during the directing step, applying mechanical force tending to separate the carrier from the substrate so as to supplement the thermal-assisted mechanical stress produced by the directing step.

[0097] According to a thirteenth aspect of the disclosure, there is provided an apparatus for processing a substrate. The apparatus includes: a carrier engagement member comprising an engagement surface for removable coupling to a primary surface of a carrier; and a substrate engagement member comprising an engagement surface for removable coupling to a primary surface of a substrate having a silicon, glass, glass-ceramic, or ceramic

composition, the substrate bonded to the carrier with a surface modification layer to define a bond region between the carrier and the substrate. The apparatus also includes a thermal source arranged to direct a thermal input upon an outer portion of one of the carrier and the substrate. Further, the thermal source and the engagement members are collectively arranged to control the thermal input upon the outer portion to produce a thermal-assisted mechanical stress in the bond region for a thermal input time sufficient to reduce a separation force for separating the substrate bonded to the substrate.

[0098] According to a fourteenth aspect, there is provided the apparatus of aspect 13, wherein the thermal source is a laser.

[0099] According to a fifteenth aspect, there is provided the apparatus of aspect 14, wherein the thermal input time is about 2 seconds or less.

[00100] According to a sixteenth aspect, there is provided the apparatus of any one of aspects 13-15, wherein the bond region is characterized by an adhesion energy between about 50 and 800 mJ/m².

[00101] According to a seventeenth aspect, there is provided the apparatus of any one of aspects 13-16, wherein the engagement members are adapted to separate the substrate with a force greater than or equal to the separation force.

[00102] According to an eighteenth aspect, there is provided the apparatus of any one of aspects 13-17, further comprising a fluid nozzle.

[00103] According to a nineteenth aspect, there is provided the method of any one of aspects 10-12, further comprising issuing fluid toward the separation between the carrier and the substrate so as to enlarge the separation.

Claims

What is Claimed is:

1. A method of processing a substrate, comprising the steps:

obtaining a carrier having first and second primary surfaces;

obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier with a surface modification layer to define a bond region between the carrier and the substrate; and

directing a thermal input to a portion of the second primary surface of the carrier to produce a thermal-assisted mechanical stress in a portion of the bond region,

wherein the directing step is conducted for a thermal input time sufficient to reduce a separation force for separating the carrier from the substrate after the bonding step and any additional thermal processing of the substrate prior to the directing step.

2. A method of processing a substrate, comprising the steps:

obtaining a carrier having first and second primary surfaces, and a plurality of edges; obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier using a surface modification layer to define a bond region between carrier and the substrate; and directing a thermal input to a portion of one of the edges of the carrier to produce a thermal-assisted mechanical stress in a portion of the bond region,

3. A method of processing a substrate, comprising the steps:

obtaining a carrier having first and second primary surfaces, and a plurality of edges; obtaining a substrate having a silicon, glass, glass-ceramic or ceramic composition, wherein the substrate has been bonded to the first primary surface of the carrier using a surface modification layer to define a bond region between carrier and the substrate; and directing a thermal input to an outer portion of the carrier or an outer portion of the substrate to produce a thermal-assisted mechanical stress in a portion of the bond region, wherein the directing step is conducted for a thermal input time sufficient to reduce a separation force for separating the carrier from the substrate after the bonding step and any additional thermal processing of the substrate prior to the directing step.

4. The method of any one of claims 1-3, wherein the substrate is a flexible substrate having a glass composition and a thickness of 300 μηι or less, and the carrier has a glass composition and a thickness from about 200 μηι to about 1 mm.

5. The method of any one of claims 1 -3, wherein the thermal input is produced by a laser.

6. The method of claim 5, wherein the thermal input time is about 2 seconds or less.

7. The method of any one of claims 1-3, wherein the substrate comprises one or more optoelectronic device elements.

8. The method of any one of claims 1-3, further comprising the step:

separating the carrier from the substrate at a force greater than or equal to the separation force after the directing step has been completed.

9. The method of any one of claims 1-3, wherein the bonding step is conducted to define a bond region having an adhesion energy between about 50 and 800 mJ/m².

10. The method of any one of claims 1-3, wherein the directing step is conducted for a thermal input time sufficient to separate at least a portion of the carrier from the substrate in the portion of the bond region.

11. The method of claim 10, further comprising issuing fluid toward the separation between the carrier and the substrate so as to enlarge the separation.

12. The method of any one of claims 1-3, wherein the directing step further produces a displacement of a portion of the carrier relative to the substrate or a portion of the substrate relative to the carrier, the displacement being monitored to control the thermal input time.

13. The method of any one of claims 1 -3, further comprising, during the directing step, applying mechanical force tending to separate the carrier from the substrate so as to supplement the thermal-assisted mechanical stress produced by the directing step.

14. An apparatus for processing a substrate, comprising:

a carrier engagement member comprising an engagement surface for removable coupling to a primary surface of a carrier;

a substrate engagement member comprising an engagement surface for removable coupling to a primary surface of a substrate having a silicon, glass, glass-ceramic or ceramic composition, the substrate bonded to the carrier with a surface modification layer to define a bond region between the carrier and the substrate; and

a thermal source arranged to direct a thermal input upon an outer portion of one of the carrier and the substrate,

wherein the source and the engagement members are collectively arranged to control the thermal input upon the outer portion to produce a thermal-assisted mechanical stress in the bond region for a thermal input time sufficient to reduce a separation force for separating the substrate bonded to the substrate.

15. The apparatus of claim 14, wherein the thermal source is a laser.

16. The apparatus of claim 15, wherein the thermal input time is about 2 seconds or less.

17. The apparatus of any one of claims 14-16, wherein the bond region is characterized by an adhesion energy between about 50 and 800 mJ/m².

18. The apparatus of any one of claims 14-16, wherein the engagement members are adapted to separate the substrate bonded to the substrate with a force greater than or equal to the separation force.

19. The apparatus of any one of claims 14-16, further comprising a fluid nozzle.