KR20150127274A - Bulk annealing of glass sheets - Google Patents

Abstract

The surface modification layer 30 (which may be provided on the sheet 20, the carrier 10, or both) to control both room temperature van der Waals (and / or hydrogen) bonding between the thin sheet and the carrier and the high temperature covalent bond ) And associated thermal processing. Room temperature bonding is controlled to be sufficient to hold the thin sheet and the carrier together during, for example, vacuum processing, wet processing, and / or ultrasonic cleaning processing. And at the same time, the high temperature covalent bonding is controlled to prevent permanent bonds between the thin sheet and the carrier during hot working, as well as to maintain sufficient bonding to prevent delamination during hot working.

Description

[0001] BULK ANNEALING OF GLASS SHEETS [0002]

Priority is claimed on U.S. Serial No. US14 / 047251, filed on October 7, 2013, under 35 USC §120, and assigned to 35 U.S.C. U.S. Provisional Application Serial No. 61 / 791,418 filed on March 15, 2013 under § 119, the contents of which are incorporated herein by reference in their entirety.

Field of invention

The invention relates to an article and a method for processing a flexible sheet on a carrier, and more particularly to an article and method for processing a flexible glass sheet on a glass carrier.

Flexible substrates offer the promise of lower cost devices using roll-to-roll processing, and the possibility of producing thinner, lighter, more flexible, and more durable displays. However, the techniques, equipment and methods required for roll-to-roll processing of high-quality displays have not yet been fully developed. Since panel manufacturers have already invested heavily in tool sets for processing large sheets of glass, it has become more and more necessary to laminate the flexible substrate to the carrier and to manufacture the display device by sheet-to-sheet processing is thinner, lighter, It provides a more short-term solution to developing valuable proposals for display of gender. The display was demonstrated in polymer sheets, such as polyethylene naphthalate (PEN), where the device fabrication was sheet-to-sheet with PEN laminated to a glass carrier. The upper temperature limit of PEN limits the device quality and process that can be used. The high transparency of the polymer substrate also leads to environmental degradation of OLED devices that require a substantially sealed package. Thin-film encapsulation offers promise to overcome this limitation, but it has not yet been proven to provide acceptable yields at large doses.

In a similar manner, a display device may be fabricated using a laminated glass carrier on one or more thin glass substrates. It is expected that the low permeability of thin glass and improved resistance to temperature and chemical resistance will enable flexible displays with longer life than higher performance.

However, heat, vacuum, solvent and acid, and ultrasonic, flat panel display (FPD) processes require strong bonding to thin glass bonded to a carrier. The FPD process typically involves vacuum deposition (chemical vapor deposition (CVD) deposition of sputtering metals, transparent conductive oxides and oxide semiconductors, amorphous silicon, silicon nitride, and silicon dioxide, and dry etching of metals and insulators) (Metal etch, oxide semiconductor etch), solvent exposure (dry etching), chemical vapor deposition (CVD) deposition, p-Si crystallization below 600 캜, oxide semiconductor annealing at 350 캜 450 캜, dopant annealing at 650 캜 or lower, Stripping photoresist, deposition of polymer encapsulation), and ultrasound exposure (in solvent stripping and aqueous cleansing of the photoresist, typically in an alkaline solution).

Adhesive wafer bonding has been widely used in micromechanical systems (MEMS) and semiconductor processing for later, less severe process steps. Commercial adhesives by Brewer Science and Henkel are thicker polymeric adhesive layers, typically 5-200 micrometers thick. The broad thickness of these layers leads to the possibility to contaminate large amounts of volatiles, trapped solvents, and adsorbed paper FPD processes. These materials are thermally decomposed and emit gases above ~ 250 ° C. The material may also cause contamination in the downstream stage by acting as a sink for gases, solvents and acids, which can release gases in subsequent processes.

U.S. Provisional Serial No. 61 / 596,727 (hereafter US '727), filed February 8, 2012, entitled Processing Flexible Glass with a Carrier, is first described by Van der Waals force (E. G., An electronic or display device, a component of an electronic or display device, an organic light emitting device (OLED) material, a photovoltaic (PV) Discloses a concept that includes increasing the bond strength in a particular region while maintaining the ability to remove portions of the thin sheet after processing a thin sheet / carrier to form a thin film transistor. At least a portion of the thin glass is attached to the carrier to reduce the possibility of contamination of the downstream process, i. E. The sealing portion coupled between the thin sheet and the carrier is hermetic, and some preferred < In an embodiment, the seal covers the exterior of the article to prevent liquid or gas penetration into or out of any area of the sealed article.

US '727 continues to demonstrate that temperature, vacuum, and wet etch environments close to 600 ° C or above can be used in low temperature polysilicon (LTPS) (low temperature compared to solid phase crystallization processes, which can be below about 750 ° C) . These conditions limit the materials that can be used and cause high demands on the carrier / thin sheet. Thus, it is possible to process thin glass, i.e., glass having a thickness of? 0.3 mm, without contamination or loss of bond strength between the thin glass and the carrier at high process temperatures, and at the end of the process, Carrier approach that utilizes the manufacturer's existing capital infrastructure is desirable.

One commercial advantage for the approach disclosed in US '727 is that the manufacturer can use a thin glass sheet for PV, OLED, LCD and patterned thin film transistor (TFT) It would be possible to use their existing capital infrastructures in process equipment while benefiting. Additionally, the approach may be used for cleaning and surface preparation of thin glass sheets and carriers to facilitate bonding; To enhance the bond between the thin sheet and the carrier in the bond region; In order to maintain the possibility of releasing the thin sheet from the carrier in the non-bonded (or reduced / low-strength bonded) region; And the like process flexibility for cutting thin sheets to facilitate removal from the carrier.

In the glass-to-glass bonding process, the glass surface is cleaned to remove all metal, organic and particulate residues, leaving mostly the silanol-terminated surface. The glass surface is first brought into intimate contact so that van der Waals and / or hydrogen-bonding forces attract the glass surface together. Using heat and optionally pressure, the surface silanol groups are condensed to form strong shared Si-O-Si bonds across the interface and to permanently fuse the glass fragments. The metal, organic and particulate residues will block the bond by blocking the intimate contact required for the bond by covering the surface. High silanol surface concentrations are also required to form strong bonds, since the number of bonds per unit area will be determined by the probability that two silanol species on opposite surfaces will react and condense into water. Zhuravlel reported that the average number of hydroxyls per nm ² for well hydrated silica was 4.6 to 4.9. (Zhuravlel, LT, The Surface Chemistry of Amorphous Silica, Zhuravlev Model, Colloids and Surfaces A: Physiochemical Engineering Aspects 173 (2000) 1-38). In US '727, a non-bonding region is formed in the bonded periphery, and the main way described for forming such a non-bonding region is to increase the surface roughness. The average surface roughness above 2 nm Ra can prevent glass-to-glass bond formation during the elevated temperature of the bonding process. U.S. Provisional Patent Application Serial No. 61 / 736,880, filed December 13, 2012 entitled Facilitated Processing for Controlling Bonding Between Sheet and Carrier, to control bond between a sheet and a carrier by the same inventor In the following, in US '880, the controlled bonding region is formed by controlling van der Waals and / or hydrogen bonding between the carrier and the thin glass sheet, but the covalent bonding region is still used. Thus, articles and methods for processing thin sheets in US '727 and US' 880 using a carrier are capable of withstanding the harsh environment of the FPD process, but are not covalently bonded (e.g., Si-O -Si) bonded region, for example a bonded region bonded at an adhesive strength of ~ 1000-2000 mJ / m ² , which is the breaking strength of approximately glass, the carrier can be reused by a strong covalent bond between the thin glass and the glass carrier I will not. Using frying or peeling can not separate the covalently bonded portion of the thin glass from the carrier and therefore can not remove the entire thin sheet from the carrier. Instead, a line is drawn and removed in the non-bonding area with the device thereon, leaving only the marginal margins of the thin glass sheet on the carrier.

In view of the above, it is possible to withstand the harshness of FPD machining, including high temperature machining (without the emission of gases that may be non-compatible with the semiconductor or display fabrication process to be used) There is a need for a thin sheet-carrier article that allows the entire area to be removed from the carrier (all at once or in portions). The present specification describes a way to control the adhesion between a carrier and a thin sheet to create a temporary bond that is sufficiently strong to withstand FPD processing (including LTPS processing) but weak enough to allow debonding of the sheet from the carrier even after a high temperature process . This controlled coupling can be used to produce an article having a re-usable carrier, or alternatively, an article having a patterned area of controlled engagement and covalent bond between the carrier and the sheet. More particularly, the present disclosure relates to a surface modification layer (which may be provided on a thin sheet, carrier, or both) to control room temperature van der Waals and / or both hydrogen bonds and high temperature covalent bonds between the thin sheet and the carrier And associated surface heat treatment). More specifically, the room temperature bonding can be controlled to be sufficient to hold the thin sheet and the carrier together during vacuum processing, wet processing, and / or ultrasonic cleaning processing. And at the same time, the high temperature covalent bond can be controlled to prevent permanent bonds between the thin sheet and the carrier during hot working, as well as to maintain sufficient bonding to prevent delamination during hot working. In an alternative embodiment, a surface modification layer may be used to provide additional processing options, for example, a covalent bond region for providing hermeticity between the carrier and the sheet even after dicing the article into smaller pieces for further device processing , The carrier and sheet may remain sufficiently bonded during various processes, including vacuum processing, wet processing, and / or ultrasonic cleaning processing. In addition, some surface modification layers provide control of bonding between the carrier and the sheet while simultaneously reducing gas emissions during harsh conditions in an FPD (e.g., LTPS) processing environment, including high temperature and / or vacuum processing do.

Additional features and advantages will be set forth in the detailed description which follows, and in part will be obvious from the description, or may be learned by practice of various aspects as illustrated in the accompanying drawings and the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary only of various aspects and are intended to provide an overview or framework for understanding the nature and features of the invention as claimed.

The accompanying drawings are included to provide a further understanding of the principles of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments (s) and, together with the description, serve to illustrate, by way of example, the principles and operation of the invention. It is to be understood that the various features disclosed in this specification and the drawings may be used in any and all combinations. As a non-limiting example, various features may be combined with one another as described later in the specification.

1 is a schematic side view of an article having a carrier bonded to a thin sheet with a surface modification layer therebetween.
Figure 2 is an exploded view and a partial perspective view of the article of Figure 1;
Figure 3 is a graph of surface hydroxyl concentration for silica as a function of temperature.
4 is a graph of the surface energy of the SC1-cleaned sheet of glass as a function of the annealing temperature.
Figure 5 is a graph of the surface energy of a thin fluoropolymer film deposited on a sheet of glass as a function of the percentage of one of the constituent materials from which the film is made.
Figure 6 is a top schematic view of a thin sheet bonded to a carrier by a bond region.
Figure 7 is a schematic side view of a stack of glass sheets.
8 is an exploded view of one embodiment of the stack of FIG.
Figure 9 is a schematic diagram of the test setup.
Figure 10 is a set of graphs of surface energy versus time (of different parts of the test setup of Figure 9) for various materials under different conditions.
Figure 11 is a graph of the change in% bubble area versus temperature for various materials.
Figure 12 is another graph of change in% bubble area versus temperature for various materials.

In the following detailed description, for purposes of explanation and not limitation, an exemplary embodiment disclosing the specific details is set forth in order to provide a thorough understanding of the various principles of the invention. However, it will be apparent to those of ordinary skill in the art having the benefit of the present disclosure that the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. Furthermore, the description of well-known devices, methods and materials may be omitted so as not to obscure the description of the various principles of the invention. Finally, where applicable, like reference numerals refer to like elements.

Ranges may be expressed herein as "about" one specific value and / or to "about" another specific value. Where such a range is expressed, another embodiment includes one specific value and / or another specific value. Similarly, it will be appreciated that when expressing values as approximations using the prefix "about ", certain values form another embodiment. It should be further understood that the endpoints of each range are significant both with respect to the other endpoints and independently of the other endpoints.

The directional terms used herein, for example, up, down, right, left, front, back, top, bottom - are made with respect to the drawings only as shown and are not intended to represent absolute directions.

The singular forms as used herein include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "an element" includes aspects having two or more such elements unless the context clearly dictates otherwise.

US 61 / 596,727 and US61 / 736,880 filed February 8, 2012 entitled " Processing Flexible Glass with a Carrier " (Filed December 13, 2012 under the title Facilitated Processing for Controlling Bonding Between Sheet and Carrier), at least a portion of the thin glass sheet remains "unbonded" and is processed on a thin glass sheet A solution is provided that allows the processing of a thin glass sheet on the carrier so that the device can be removed from the carrier. However, the periphery of the thin glass is permanently bonded (or covalently bonded, or hermetically) to the carrier glass through the formation of a shared Si-O-Si bond. The covalently bonded peripheries prevent reuse of the carrier because thin glass can not be removed without damage to the thin glass and carrier in the permanently bonded area.

To maintain favorable surface profile characteristics, the carrier is typically a display grade glass substrate. Thus, in some circumstances, simply discarding the carrier after a single use is wasteful and costly. Thus, in order to reduce the cost of display manufacture, it is desirable to be able to reuse the carrier to process more than one thin sheet substrate. The present disclosure is based on the assumption that the thin sheet is subjected to high temperature processing where the high temperature processing is at a temperature of < RTI ID = 0.0 > 400 C < / RTI > and can vary greatly depending on the type of apparatus being manufactured, for example amorphous silicon or amorphous indium gallium zinc oxide (IGZO) A temperature of about 450 DEG C or less as in the case of processing, about 500-550 DEG C or less as in the case of crystalline IGZO processing, or a temperature of about 600-650 DEG C or less as typical in an LTPS process. Environment, but also allows the thin sheet to be easily removed from the carrier without damaging the thin sheet or carrier (e.g., one of the carrier and the thin sheet breaking into or breaking into two or more pieces) Thereby allowing the carrier to be reused.

1 and 2, the glass article 2 has a carrier 10 having a thickness 8 and a thickness 18, a thin sheet 20 having a thickness 28 (i. 10 to 50 micrometers, 50 to 100 micrometers, 100 to 150 micrometers, 150 to 300 micrometers, 300, 250, 200, 190, 180, 170, 160, 150, 140, 130, 120, A sheet having a thickness of? 300 micrometers, including but not limited to a thickness of 90, 80, 70, 60, 50, 40, 30, 20, or 10 micrometers) And a reforming layer (30). The glass article 2 is a thicker sheet (i. E. About .4 mm, such as .4 mm, .5 mm, .6 mm, .7 mm , .8 mm, .9 mm, or 1.0 mm) in the machine. That is, the thickness 8, which is the sum of the thicknesses 18, 28, and 38, is the thickness of the thicker sheet 8 that has been devised to process one piece of equipment-for example, equipment designed to place electronic components on the substrate sheet- Is equal to the thickness of the layer. For example, if the processing equipment is designed for a 700 micrometer sheet and the thin sheet has a thickness 28 of 300 micrometers, then the thickness 18 is assumed to be such that the thickness 38 is negligible , And 400 micrometers. That is, the surface modification layer 30 is not shown at a constant rate; Instead, it is largely exaggerated for illustrative purposes only. Further, the surface modification layer is shown in a perspective view. In practice, the surface modification layer will be uniformly disposed over the bonding surface 14 when providing a reusable carrier. Typically, the thickness 38 will be approximately nanometers, for example 0.1 to 2.0, or 10 nm or less, and in some instances 100 nm or less. The thickness 38 may be measured by an ellipsometer. In addition, the presence of the surface modification layer can be detected by surface chemical analysis, for example, ToF Sims mass spectrometry. The contribution of the thickness 38 to the article thickness 8 is negligible and the thickness 18 of the carrier 10 suitable for machining a given thin sheet 20 having a thickness 28 is determined Can be ignored in the calculation for. However, to the extent that the surface modification layer 30 has any significant thickness 38, such is the case if the thickness 18 of the carrier 10 is greater than a given thickness 28 of the thin sheet 20, Lt; RTI ID = 0.0 > thickness. ≪ / RTI >

The carrier 10 has a first surface 12, a mating surface 14, a peripheral portion 16, and a thickness 18. In addition, the carrier 10 may have any suitable material, including, for example, glass. The carrier need not be glass, but may instead be a ceramic, glass-ceramic, or metal (because surface energy and / or bonding can be controlled in a manner similar to that described below with respect to the glass carrier). When made of glass, the carrier 10 may have any suitable composition, including an aluminosilicate, boro-silicate, alumino-boro-silicate, soda-lime-silicate, Alkali - Mullion can be unique. The thickness 18 may be greater than or equal to about 0.2 to 3 mm, such as 0.2, 0.3, 0.4, 0.5, 0.6, 0.65, 0.7, 1.0, 2.0, or 3 mm, , And thickness 38 are not negligible. The carrier 10 may also be comprised of a plurality of layers (including a plurality of thin sheets), either as a single layer or as joined together, as shown. In addition, the carrier may have a size greater than or equal to a Gen 1 size, such as Gen 2, Gen 3, Gen 4, Gen 5, Gen 8 or greater (e.g., sheet size 100 mm x 100 mm to 3 meters x 3 meters or more) have.

The thin sheet 20 has a first surface 22, a mating surface 24, a peripheral portion 26, Peripheral portions 16 and 26 may have any suitable shape, may be identical to each other, or may be different from each other. In addition, the thin sheet 20 may have any suitable material, including, for example, glass, ceramic, or glass-ceramic. When made of glass, the thin sheet 20 may have any suitable composition, including an aluminosilicate, a boro-silicate, an alumino-boro-silicate, a soda-lime-silicate, Containing or alkali-free. The coefficient of thermal expansion of the thin sheet could be matched relatively close to the coefficient of thermal expansion of the carrier to prevent distortion of the article during processing at elevated temperatures. The thickness 28 of the thin sheet 20 is 300 micrometers or less, as mentioned above. In addition, the thin sheet may have a size greater than or equal to the size of Gen 1, such as Gen 2, Gen 3, Gen 4, Gen 5, Gen 8 or more (e.g., sheet size 100 mm x 100 mm to 3 meters x 3 meters or more) .

The article 2 will not only need to be machined to exact thickness in existing equipment, but also be able to withstand the harsh environment in which the machining is performed. For example, flat panel display (FPD) processing may include wet ultrasonic, vacuum, and high temperature processing (e.g., ≥400 ° C). In some processes, as noted above, the temperature may be ≥ 500 캜, or ≥ 600 캜, and 650 캜 or lower.

The engagement surface 14 is formed with sufficient strength to prevent the thin sheet 20 from being detached from the carrier 10, such as during FPD manufacturing, to withstand the harsh environment in which the article 2 is to be processed. Lt; / RTI > And the strength must be maintained throughout the entire machining process so that the thin sheet 20 is not detached from the carrier 10 during machining. Also, to enable the thin sheet 20 to be removed from the carrier 10 (so that the carrier 10 can be reused), the mating surface 14 can be formed by initially designed bonding force and / The article should not be too strongly bonded to the bonding surface 24 by the bonding force caused by a change in bonding force originally designed, such as may occur when the article undergoes processing at a high temperature, for example, at a temperature of ≥ 400 ° C. The surface modification layer 30 can be used to control the strength of the bond between the bonding surface 14 and the bonding surface 24 to achieve both of these purposes. Controlled binding force can be controlled by controlling the van der Waals (and / or hydrogen bonding) and the contribution of the shared attraction energy to the total adhesive energy controlled by adjusting the polarity and non-polar surface energy components of the thin sheet 20 and the carrier 10 . The controlled bond can withstand the FPD process (including thermal processes including wet, ultrasonic, vacuum, and ≥400 ° C temperature, and in some cases ≥500 ° C, or ≥600 ° C, and processing temperatures below 650 ° C in some cases) Remain sufficiently strong and detachable by application of sufficient separation force and by force not to cause catastrophic damage to the thin sheet 20 and / or the carrier 10. [ This debonding allows removal of the thin sheet 20 and the device fabricated thereon, and also permits the reuse of the carrier 10.

Although the surface modification layer 30 is shown as a solid layer between the thin sheet 20 and the carrier 10, such need not be the case. For example, the layer 30 may be approximately 0.1 to 2 nm thick and may not completely cover the entire surface of the bonding surface 14. For example, the coverage can be ≤ 100%, 1% to 100%, 10% to 100%, 20% to 90%, or 50% to 90%. In another embodiment, layer 30 may be less than or equal to 10 nm thick, or in other embodiments, less than or equal to 100 nm thick. The surface modification layer 30 may be considered to be disposed between the carrier 10 and the thin sheet 20 even though it may not be in contact with either the carrier 10 or the thin sheet 20. [ In any case, an important aspect of the surface modification layer 30 is to modify the ability of the bonding surface 14 to engage the bonding surface 24 to improve the strength of the bond between the carrier 10 and the thin sheet 20 . The treatment of the bonding surface 14,24 prior to bonding as well as the material and thickness of the surface modification layer 30 can be used to control the strength of the bond between the carrier 10 and the thin sheet 20 have.

In general, the adhesive energy between two surfaces is given by ("A theory for the estimation of surface and interfacial energies I. derivation and application to interfacial tension ", LA Girifalco and RJ Good, J. Phys. Chem. V 61, p 904):

&Quot; (1) "

는 각각 표면 1, 표면 2의 표면 에너지, 및 표면 1 및 2의 계면 에너지이다. 각각의 표면 에너지는 보통 두 항; 분산 성분 γ^d, 및 극성 성분 γ^p의 조합이다.In this formula,

Are surface energy of surface 1, surface 2, and surface energy of surfaces 1 and 2, respectively. Each surface energy is usually divided into two terms; A dispersive component? ^D , and a polar component? ^P.

&Quot; (2) "

If the adhesion is mainly due to the London dispersibility (y ^d ) and the polarity forces, such as hydrogen bonds (y ^p ), the interfacial energies could be given by (Girifalco and RJ Good as mentioned above) :

&Quot; (3) "

After substituting Equation (3) into Equation (1), the adhesive energy can be roughly calculated as follows:

&Quot; (4) "

In Equation (4), only the van der Waals (and / or hydrogen bonding) component of the adhesive energy is considered. These include polar-polar interactions (Keesom), polar-nonpolar interactions (Debye) and nonpolar-nonpolar interactions (London). However, other attraction energy, for example covalent and electrostatic, may also be present. Thus, in a more generalized form, the equation is described as:

Equation (5)

Where w _c and w _e are the covalent and electrostatic adhesion energies. Shared adhesion energy is rather common, such as in silicon wafer bonding, where the initial hydrogen-bonded pair of wafers is heated to a higher temperature to convert many or all of the silanol-silanol hydrogen bonds to Si-O-Si covalent bonds. The initial, room temperature, hydrogen bonding produces an adhesive energy of approximately ~100-200 mJ / m < ² > to allow separation of bonded surfaces, while a fully covalently bonded wafer, such as that achieved during high temperature processing (approximately 400-800 DEG C) The pair has an adhesive energy of ~ 1000-3000 mJ / m ^{2 which} does not allow separation of the bonded surface; Instead, the two wafers act as monoliths. On the other hand, if both surfaces are completely coated with a low surface energy material, such as a fluoropolymer, with a thickness large enough to mask the effect of the underlying substrate, Will be energy and will be so low that it will not result in a low adhesion between the bonding surfaces 14 and 24 or will not result in an adhesion force so that the thin sheet 20 will not be able to be machined on the carrier 10. [ Consider two extreme cases: (a) a double standard clean 1 (SC1, as known in the art) a glass surface saturated with a cleaned silanol group is hydrogen bonded (with an adhesive energy of ~ 100-200 mJ / m ² ) at room temperature and then heated to a high temperature to convert the silanol groups to a shared Si-O-Si bond (thereby resulting in an adhesive energy of 1000-3000 mJ / m ² ). The latter adhesive energy being too high to make the pair of glass surfaces detachable; (b) Two glass surfaces that are completely coated with a fluoropolymer are bonded at room temperature with low surface bonding energy (~ 12 mJ / m ² per surface) and heated to a high temperature. In the case of the latter (b), the surface is not only bonded (because the total adhesion energy of ~ 24 mJ / m ² is too low when the surfaces are combined), but also because the surface has no polar reactors (or too little) Lt; / RTI > Between these two extremes, the range of adhesive energies is, for example, 50-1000 mJ / m ² , which can produce the desired degree of controlled binding. Thus, the present inventors have discovered that a pair of glass substrates (e.g., glass carrier 10 and thin glass sheet 20) coupled to each other can be maintained during the harshness of FPD processing by inducing adhesive energy between these two extremes (E.g., even after high temperature machining at > 400 [deg.] C), a controlled bond can be created to such an extent as to permit the detachment of the thin sheet 20 from the carrier 10 after machining is completed A variety of ways of providing the surface modification layer 30 have been found. It should also be appreciated that detachment of the thin sheet 20 from the carrier 10 can be achieved by mechanical force and without at least damage to the thin sheet 20 and thus preferably also without catastrophic damage to the carrier 10. [ Lt; / RTI >

Equation 5 describes that the adhesive energy is a function of four surface energy parameters plus the covariance and electrostatic energy when present.

Appropriate adhesive energy may be achieved by careful selection of the surface modifier, i. E., The surface modification layer 30, and / or the surface treatment prior to bonding. Suitable bonding energies may be achieved by the choice of chemical modifier (s) of one or both of bonding surface 14 and bonding surface 24, resulting in van der Waals (and / or hydrogen bonding, (E. G., About < RTI ID = 0.0 > 400 C) < / RTI > as well as adhesive energy. For example, take the bonding surface of SC1 cleaned glass (initially saturated with silanol groups with high polarity components of surface energy) and coat it with a low energy fluoropolymer so that the functional coverage of the surface by polar and non- Lt; / RTI > This not only provides control of the initial van der Waals (and / or hydrogen) bonding at room temperature, but also provides control of the degree of covalent bonding / covalent bonding at higher temperatures. Control of the early Van der Waals (and / or hydrogen) bonding at room temperature can be achieved by bonding to other surfaces of the surface as long as it allows vacuum and / or spin-rinse-dry (SRD) Wherein the easily formed engagement is accomplished by using a squeegee or by applying a thin sheet 20 as is done when pressing the thin sheet 20 onto the carrier 10 using a reduced pressure environment. ≪ RTI ID = 0.0 >Lt; RTI ID = 0.0 > 20, < / RTI > That is, the initial Van der Waals bonding provides at least a minimum degree of bonding that holds the thin sheet and carrier together so that one is fixed and the other is not separated when gravity is applied. In most cases, the initial Van der Waals (and / or hydrogen) bonding will have such an extent that the article can also be subjected to vacuum, SRD, and ultrasonic machining without delamination of the thin sheet from the carrier. The surface modification layer 30 (including the surface treatment of the surface to which the surface modification layer is to be made and / or the surface modification layer is applied), and / or via thermal treatment of the bonding surface before bonding them together, The precise control at a suitable level of both the valence (and / or hydrogen bonding) and the covalent interaction allows the thin sheet 20 to engage with the carrier 10 during FPD styling, To achieve the desired adhesive energy that allows the post-thin sheet 20 to be separated from the carrier 10 (by a suitable force to prevent damage to the thin sheet 20 and / or the carrier). Also, under the right circumstances, static charge could be applied to one glass surface or both to provide control of another level of adhesive energy.

FPD processing, such as p-Si and oxide TFT fabrication, typically requires a temperature above 400 [deg.] C to cause glass-to-glass bonding that couples the thin glass sheet 20 to the glass carrier 10 in the absence of the surface modification layer 30. [ , Above 500 ° C, and in some cases above 600 ° C and below 650 ° C. Control of the formation of Si-O-Si bonds therefore leads to reusable carriers. One way to control the formation of Si-O-Si bonds at elevated temperatures is to reduce the concentration of surface hydroxyl on the surface to be bonded.

As shown in Figure 3, which is a plot of Iler of surface hydroxyl concentration on silica as a function of temperature (RK Iller: The Chemistry of Silica (Wiley-Interscience, New York, 1979) The heating of the silica surface (and the glass surface, e.g., bonding surface 14 and / or bonding surface 24, by analogy) Reducing the concentration of hydroxyl reduces the likelihood of hydroxyl interactions on both glass surfaces. This reduction in surface hydroxyl concentration results in a decrease in the Si-O-Si bond formed per unit area, thus lowering the adhesion. However, the removal of the surface hydroxyl requires a long annealing time at a high temperature (more than 750 DEG C to completely remove the surface hydroxyl). This long annealing time and high annealing temperature are expensive processes, There is the potential to exceed the strain point of the glass type of the display results in a process that is not practical.

From the above analysis, the inventors have found that articles suitable for FPD processing (including LTPS processing), including thin sheets and carriers, can be manufactured by balancing the following three concepts:

(1) intermediate bonding sufficient to control the bonding of the van der Waals (and / or hydrogen) bonds to facilitate initial room temperature bonding and to withstand non-high temperature FPD processes such as vacuum processing, SRD processing, and / And / or thin sheet bonding surfaces (e.g., by controlling initial room temperature bonding, which may be performed by creating energy (e.g., having a surface energy of > 40 mJ / m ² per surface before bonding the surface) );

(2) in a thermally stable manner to tolerate the FPD process without the release of interlayer delamination and / or unacceptable contamination in the fabrication of the device, for example gases that can cause unacceptable contamination of the semiconductor and / Surface modification of the carrier and / or thin sheet of carrier; And

(3) the carrier surface hydroxyl concentration, and the concentration of other species capable of forming strong covalent bonds at elevated temperatures (e.g., > = 400 [deg.] C temperature) , The adhesion between the carrier and the thin sheet does not damage the at least thin sheet (preferably, but not damaging the thin sheet or carrier), while the carrier and the thin sheet do not damage the sheet during processing Wherein the bond energy between the bond surface of the carrier and the thin sheet can be controlled such that it is within a range that allows sufficient debonding of the thin sheet from the carrier, Control of bonding at high temperature.

The present inventors have also found that the use of the surface modification layer 30 allows the controlled bonding region, that is, the article 2, to be processed in an FPD type process (including vacuum and wet processes) Temperature bond between the thin sheet 20 and the carrier 10 sufficient to cover the carrier 10 after the article 2 has undergone a high temperature processing such as FPD type processing or LTPS processing To control the covalent bond between the thin sheet 20 and the carrier 10 so that it can be removed from the sheet 20 (without damage to at least the thin sheet, and preferably without damage to the carrier) It is possible to achieve a balance with the above concept to easily achieve the area. A series of tests were used to assess the suitability of each to provide a reusable carrier suitable for FPD processing, potential bonding surface preparation, and to evaluate the surface modification layer. Although different FPD applications have different requirements, the LTPS and oxide TFT processes appear to be the most stringent at this point, and therefore tests representative of the steps in this process have been selected because they are the desired applications for article (2). Vacuum processes, wet scrubbing (including SRD and ultrasonic type processes) and wet etching are typical for many FPD applications. Typical aSi TFT fabrication requires processing below 320 ° C. Annealing at 400 [deg.] C is used in the oxide TFT process while crystallization and dopant activation above 600 [deg.] C are used in LTPS processing. Thus, the following five tests can be used to allow a specific bonding surface preparation and surface modification layer 30 to keep the thin sheet 20 bonded to the carrier 10 during FPD processing, while such processing (& The possibility of allowing the thin sheet 20 to be removed from the carrier 10 (without damaging the thin sheet 20 and / or the carrier 10) after the heat treatment (including processing at the temperature) is evaluated. The tests were carried out in order and the samples were progressed from one test to the next unless there was a type failure that would not allow subsequent tests.

(1) Vacuum test. Vacuum conformance testing was performed on an STS Multiplex PECVD loadlock (available from SPTS, Newport, NJ) - the load lock was an Ebara A10S dry pump with a soft pump valve (Sacramento, Calif. (Available from Ebara Technologies Inc.). ≪ / RTI > After placing the sample on the load-lock, the load-lock was pumped within 45 seconds from atmospheric pressure to 70 mTorr. Failure, as indicated by the notation "F" in the "vacuum" column of the table below, was considered to have occurred if: (a) loss of adhesion between the carrier and the thin sheet Failure was considered to have occurred if the thin sheet fell off the carrier or was partially debonded therefrom); (b) Bubbling between the carrier and the thin sheet (as determined by visual inspection by the naked eye - after taking a picture of the sample before and after machining, the failure was the case when the defect increased in size by the dimensions visible to the naked eye Determined); Or (c) movement of the thin sheet relative to the carrier (as determined by visual inspection in the naked eye - taking a picture of the sample before and after the test, where the failure is the movement of the bonding defect, for example when there is a bubble, Or when there is a thin sheet of movement on the carrier). In the following table, the notation "P" in the "vacuum" column indicates that the sample did not fail according to the above criteria.

 (2) Wet process test. Wet process conformance testing was performed using the Semitool model SRD-470S (available from Applied Materials, Santa Clara, Calif.). The test consisted of a rinse of 500 rpm for 60 seconds, Q-rinse at 15 MOhm-cm at 500 rpm, 10 seconds of purging at 500 rpm, 90 seconds of drying at 1800 rpm and 180 seconds of drying at 2400 rpm under warm flowing nitrogen. Failure, as indicated by the notation "F" in the column "SRD" in the table below, was considered to have occurred if: (a) loss of adhesion between the carrier and the thin sheet Failure was considered to have occurred if the thin sheet fell off the carrier or was partially debonded therefrom); (b) Bubbling between the carrier and the thin sheet (as determined by visual inspection by the naked eye - after taking a picture of the sample before and after machining, the failure was the case when the defect increased in size by the dimensions visible to the naked eye Determined); Or (c) movement of the thin sheet relative to the carrier (as determined by visual inspection in the naked eye - taking a picture of the sample before and after the test, where the failure is the movement of the bonding defect, for example when there is a bubble, Or (d) penetration of water beneath the thin sheet (as determined by visual inspection at 50x with an optical microscope, where the failure is due to the presence of liquid Or the residue was determined to be observable.) In the table below, the notation "P" in the column "SRD" indicates that the sample did not fail according to the above criteria.

(3) Temperature test up to 400 ℃. The 400 < 0 > C process suitability test was performed using Alwin21 Accuthermo 610 RTP (available from Alwyn 21, Santa Clara, Calif.). To which a thin sheet bonded carrier was heated from room temperature to 400 占 폚 at 6.2 占 폚 / min, held at 400 占 폚 for 600 seconds, and cooled in a cycle of 1 占 폚 / min to 300 占 폚. The carrier and the thin sheet were then allowed to cool to room temperature. Failure, as indicated by the notation "F" in the "400 ° C" column of the table below, was considered to have occurred when: (a) loss of adhesion between the carrier and the thin sheet , Where the failure was considered to have occurred if the thin sheet had fallen from the carrier or was partially debonded therefrom); (b) Bubbling between the carrier and the thin sheet (as determined by visual inspection by the naked eye - after taking a picture of the sample before and after machining, the failure was the case when the defect increased in size by the dimensions visible to the naked eye Determined); Or (c) an increased adhesion between the carrier and the thin sheet, wherein such increased adhesion is achieved by insertion of a razor blade between the thin sheet and the carrier and / or by Kapton ™ tape, 1 "wide x 6" The slices may be applied to a thin sheet or carrier (such as by affixing the thin 2-3 "sheet to a thin sheet attached to a thin 100 mm square glass (K102 series from Saint Gobain Performance Plastic, New York) and pulling the tape) Wherein the failure can be avoided if there is damage to the thin sheet or carrier in an attempt to detach the thin sheet or carrier, or if the thin sheet and the carrier are in any of the detachment methods It is believed to have occurred in the event that it can not be debonded by the performance of the carrier.) Also, after bonding the thin sheet to the carrier, Prior to thermocycling, a debinding test was performed on representative samples to determine that certain materials, including any associated surface treatments, allowed debonding of the thin sheet from the carrier prior to temperature cycling. The notation "P" in the column indicates that the sample did not fail according to the above criteria.

(4) Temperature test up to 600 ℃. The 600 < 0 > C process suitability test was performed using Alwyn 21 Accuilo 610 RTP. The carrier containing the thin sheet was circulated from room temperature to 600 DEG C at 9.5 DEG C / min, held at 600 DEG C for 600 seconds, and then heated in a chamber cooled to 300 DEG C at 1 DEG C / min. The carrier and the thin sheet were then allowed to cool to room temperature. Failure, as indicated by the notation "F" in the "600 ° C" column of the following table, was considered to have occurred if: (a) loss of adhesion between the carrier and the thin sheet , Where the failure was considered to have occurred if the thin sheet had fallen from the carrier or was partially debonded therefrom); (b) Bubbling between the carrier and the thin sheet (as determined by visual inspection by the naked eye - after taking a picture of the sample before and after machining, the failure was the case when the defect increased in size by the dimensions visible to the naked eye Determined); Or (c) an increased adhesion between the carrier and the thin sheet, wherein such increased adhesion is achieved by applying a piece of Capton (TM) tape as described above to the thin sheet by insertion of a razor between the thin sheet and the carrier, and / To prevent debonding of the thin sheet from the carrier without damage to the thin sheet or carrier, wherein the failure can be avoided if there is damage to the thin sheet or carrier in an attempt to separate the thin sheet or carrier, Which is believed to have occurred in the event that it can not be desorbed by any of the above-mentioned debinding methods). Also, after bonding the thin sheet to the carrier and before thermocycling, a desorption test is performed on the representative sample so that the specific material, and any associated surface treatment, allows debonding of the thin sheet from the carrier before temperature cycling . In the table below, the notation "P" in the column "600 DEG C " indicates that the sample did not fail according to the above criteria.

(5) Ultrasonic test. The ultrasonic compatibility test was performed by cleaning the article in four tank lines, where the article was processed in each tank sequentially from tank # 1 to tank # 4. The tank dimensions for each of the four tanks were 18.4 "L x 10" W x 15 "D. The two wash tanks (# 1 and # 2) were filled with DI water at 50 ° C in Yokohama Yokohama Oil & 1% Semiclean KG, available from Yokohama Oils and Fats Industry Co. Ltd. Cleaning tank # 1 was a NEY Prosonic 2 104 kHz sonicator (Blackstone, NY, Jamestown, NY) NEY Ultrasonics), and rinsing tank # 2 was agitated with a NEY Prosonic 2 104 kHz sonicator. The two rinse tanks (Tank # 3 and Tank # 4) were agitated at 50 ° C The rinse tank # 3 was stirred with a NEY sweep sonic 2D 72 kHz sonicator and the rinse tank # 4 was stirred with a NEY sweep sonic 2D 104 kHz sonicator. Min, and then the sample Failure, as indicated by the notation "F" in the "Ultrasonic" column of the table below, was considered to have occurred when: (a) the carrier Loss of adhesion between the carrier and the thin sheet (by visual inspection through the naked eye, where the failure was considered to have occurred if the thin sheet fell off the carrier or was partially debonded therefrom); (b) Bubbling (as determined by visual inspection by the naked eye - the sample was photographed before and after machining and then compared and the failure was determined to have occurred when the defect increased in size to the extent visible to the naked eye); or (c) Formation of significant defects (as determined by visual inspection at 50x under an optical microscope, where failure was not observed before Considered to have occurred in the presence of trapped particles between the thin sheet and the carrier); Or (d) penetration of water beneath a thin sheet (as determined by visual inspection at 50x with an optical microscope, where the failure was determined to have occurred if the liquid or residue was observable). In the following table, the notation "P" in the "Ultrasonic" column indicates that the sample did not fail according to the above criteria. Also, in the table below, the blank or "?" In the "ultrasonic" column indicates that the sample was not tested in this manner.

Preparation of bonded surfaces by reduction of hydroxyl by heating

The advantage of modifying at least one of the engaging surfaces 14 and 24 with the surface modification layer 30 so that the article 2 can successfully undergo FPD processing (i.e., the thin sheet 20 is transferred to the carrier 10 during processing) (Which can be detached from the carrier 10 after processing, including high temperature processing), can be used to separate the article 2 having the glass carrier 10 and the thin glass sheet 20 therebetween without the surface modification layer 30, Lt; / RTI > In particular, attempts have been made to prepare the bonding surfaces 14, 24 by first heating to reduce the hydroxyl groups, but without the surface modification layer 30. The carrier 10 and the thin sheet 20 were cleaned, the bonding surfaces 14 and 24 were bonded together, and then the article 2 was tested. A typical rinsing process for preparing the bonding glass is such that the glass is free of dilute hydrogen peroxide and a base (typically ammonium hydroxide, but tetramethylammonium hydroxide solution such as JT Baker (Baker) JTB-100 or JTB-111 may also be used) It is an SC1 cleaning process to be cleaned. The cleaning removes the particles from the bonding surface and produces a known surface energy, i. E. This provides a reference value of the surface energy. Other types of cleaning may be used, since the manner of cleaning need not be SC1 and the type of cleaning may have only very little effect on the silanol groups on the surface. The results of the various tests are shown in Table 1 below.

A strong, but detachable initial, room temperature or van der Waals and / or hydrogen-bonding can be achieved using an Eagle XG display glass (commercially available from Corning Incorporated, Corning, NY, A 100 mm square x 100 micrometer thick thin glass sheet, and a 150 mm diameter single mean flat (SMF) wafer 0.50 or 0.63 mm thick, including an alumina-boron-silicate glass with an average surface roughness Ra mm < / RTI > thick glass carrier. In the above example, the glass was rinsed for 10 minutes in a 65: C bath of 40: 1: 2 DI water: JTB-111: hydrogen peroxide. A thin glass or glass carrier may or may not be annealed at 400 占 폚 for 10 minutes in nitrogen to remove residues - the notation "400" in the "carrier" column or "thin glass" column in the following Table 1 Quot; C "indicates that the sample was annealed at 400 [deg.] C for 10 minutes in nitrogen. The FPD process conformance test demonstrates that the SC1-SC1 early, room temperature, bonding is mechanically strong enough to pass the vacuum, SRD and ultrasonic tests. However, heating at 400 [deg.] C and higher resulted in permanent bonding between the thin glass and the carrier, i.e. the thin glass sheet could not be removed from the carrier without damage to one or both of the thin glass sheet and the carrier. And this was also true for Example 1c, where each carrier and thin glass had an annealing step to reduce the concentration of surface hydroxyl. Thus, the coupling of the carrier 10 and the thin sheet 12, without the above-described production of the bonding surfaces 14, 24 via heating alone, and then without the surface modification layer 30, Lt; / RTI >

<Table 1> - Process suitability test of SC1-treated glass bonded surfaces

Hydroxyl reduction and preparation of bonding surfaces by surface modifying layers

For example, hydroxyl reduction such as by thermal treatment, and surface modification layer 30 may be used together to control the interaction of the bonding surfaces 14, 24. For example, the bonding energy of the bonding surfaces 14, 24 (both van der Waals and / or hydrogen-bonding at room temperature due to polar / dispersive energy components and both covalent bonds at high temperatures due to shared energy components) Can be controlled to provide a bonding strength that varies from difficult to bond at room temperature to allowing easy room temperature bonding and separation of bonding surfaces after high temperature processing, have. In some applications, it may be desirable to have no or very weak bonds (if the surface is present in a "non-bonding" region as described in the thin sheet / carrier concept of US ' have. For example, in another application that provides a re-usable carrier for an FPD process or the like (where process temperatures ≥ 500 캜, or ≥ 600 캜, and ≤ 650 캜 can be achieved) It is desirable to have sufficient van der Waals and / or hydrogen-bonds to combine the carriers, but to prevent or limit high temperature covalent bonds. For another application, a sufficient room temperature to initially assemble the thin glass and carrier (if the surface is present in the &quot; bonding region "as described in the thin sheet / carrier concept of US '727 and discussed below) It may be desirable to have a bond and also to generate strong covalent bonds at high temperatures. While not wishing to be bound by theory, it is believed that in some cases, the room temperature bonding at which the thin sheet and the carrier initially join together can be controlled using the surface modification layer, while the surface modification of the hydroxyl groups on the surface (Or by reaction of the hydroxyl groups with the surface modifying layer) can be used to control covalent bonding, especially at elevated temperatures.

The material for the surface modification layer 30 provides a bonding surface 14, 24 having energy (e.g., energy < 40 mJ / m ² as measured at one surface, and polar and dispersive components) And thus the surface only produces weak bonds. In one example, hexamethyldisilazane (HMDS) can be used to react with the surface hydroxyl to leave such a trimethylsilyl (TMS) end surface, thus causing such a low energy surface. Both surface temperature and high temperature bonding can be controlled using HMDS as the surface modifying layer while surface heating to reduce the hydroxyl concentration. By selecting a suitable bonding surface preparation method for each bonding surface 14,24, an article having various capabilities can be achieved. More particularly, among the interesting ones to provide a reusable carrier for LTPS machining is to allow (or pass through) the respective vacuum SRD, 400 占 폚 (parts a and c), and 600 占 폚 ) A suitable bond between the thin glass sheet 20 and the glass carrier 10 can be achieved.

In one example, the HMDS treatment of both thin glass and carrier after SC1 cleaning produces a weakly bonded surface that is difficult to bond at room temperature with van der Waals (and / or hydrogen bonding) forces. Apply a mechanical force to bond the thin glass to the carrier. As shown in Example 2a of Table 2, the bonding was sufficiently weak that bending of the carrier was observed in vacuum testing and SRD processing, bubbling (probably due to gas evolution) was observed in the 400 &lt; 0 &gt; C and 600 & Defects were observed after ultrasonic machining.

In yet another embodiment, the HMDS treatment of only one surface (carrier in the cited example) produces a stronger room temperature adhesive force that withstands vacuum and SRD processing. However, the thermal process at temperatures above 400 ° C permanently bonded the thin glass to the carrier. This indicates that the maximum surface coverage of the trimethylsilyl group for silica is much less than that of the silica (Sindorf and Maciel, J. Phys. Chem. 1982, 86, 5208-5219] and was found to be 2.8 / nm ² , as described by Suratwala et. al., Journal of Non-Crystalline Solids 316 (2003) 349-363], it was measured as 2.7 / nm ² compared to a hydroxyl concentration of 4.6-4.9 / nm ² for fully hydroxylated silica, It is not work. That is, the trimethylsilyl group binds with some surface hydroxyl, but some unbound hydroxyl will remain. Thus, given sufficient time and temperature, condensation of the surface silanol groups, which will permanently bond the thin glass and the carrier, would be expected.

Varied surface energy can be generated by heating the glass surface to reduce the surface hydroxyl concentration prior to exposure to HMDS to induce increased polarity components of surface energy. This not only reduces the driving force for the formation of the covalent Si-O-Si bond at high temperature but also induces stronger room temperature bonding, for example van der Waals (and / or hydrogen) bonding. Figure 4 shows the surface energies of Eagle XG® display glass carriers after annealing and after HMDS treatment. The elevated annealing temperature prior to HMDS exposure increases the overall (polar and dispersed) surface energy (line 402) after HMDS exposure by increasing the polarity contribution (line 404). It is also believed that the dispersive contribution to total surface energy (line 406) remained largely unchanged by heat treatment. Although not wishing to be bound by theory, the increase of the polar component on the surface after the HMDS treatment, and thus the total energy increase, is due to the presence of some exposed glass surface area after the HMDS treatment due to the sub-monolayer TMS coverage by HMDS .

In Example 2b, the thin glass sheet was heated under vacuum at a temperature of 150 DEG C for 1 hour before bonding with a non-heat-treated carrier having a coating of HMDS. The heat treatment of the thin glass sheet was not sufficient to prevent permanent bonding of the thin glass sheet to the carrier at &lt; RTI ID = 0.0 &gt; 400 C. &lt; / RTI &gt;

As shown in Examples 2c-2e in Table 2, the annealing temperature of the glass surface before the HMDS exposure can be varied to change the binding energy of the glass surface to control the bond between the glass carrier and the thin glass sheet.

In Example 2c, the carrier was annealed at a temperature of 190 占 폚 under vacuum for 1 hour, and HMDS exposure was performed to provide the surface modification layer 30. In addition, the thin glass sheet was annealed at 450 占 폚 under vacuum for 1 hour before bonding with the carrier. The resulting product sustained the vacuum, SRD, and 400 ° C test (parts a and c, but did not pass part b due to increased bubbling), but failed the 600 ° C test. Thus, there is an increased resistance to high temperature bonding compared to Example 2b, but this was not sufficient to produce an article for processing at a temperature of &gt; 600 ° C where the carrier is reusable (e.g., LTPS processing).

In Example 2d, the carrier was annealed at a temperature of 340 占 폚 under vacuum for 1 hour, and HMDS exposure was then performed to provide the surface modification layer 30. Again, the thin glass sheet was annealed at 450 &lt; 0 &gt; C for 1 hour under vacuum before bonding with the carrier. The results were similar to those of Example 2c, and the article sustained a vacuum, SRD, and 400 ° C test (parts a and c, but with increased bubbling, failed to pass part b), but failed the 600 ° C test .

As shown in Example 2e, after both the thin glass and the carrier were annealed at 450 ° C under vacuum for one hour, HMDS exposure of the carrier was performed, followed by bonding the carrier and the thin glass sheet, Thereby improving resistance. Annealing of both surfaces to 450 占 폚 prevented permanent bonding after RTP annealing at 600 占 폚 for 10 minutes, i.e. the sample was subjected to a 600 占 폚 test (parts a and c, but with increased bubbling, failed to pass part b; Similar results were observed in the case of the 400 ° C test).

<Table 2> - Process suitability test of HMDS surface modifying layer

In the above Examples 2a to 2e, each carrier and thin sheet was Eagle XG® glass, where the carrier is 150 mm diameter SMF wafer 630 micrometer thick, and the thin sheet 100 mm square 100 micrometer thick. HMDS was applied by pulse deposition in a YES-5 HMDS oven (available from Yield Engineering Systems, San Jose, Calif.), Which was one atom layer thickness (i.e., about 0.2 to 1 nm) The coating may be less than one layer, i.e. some of the surface hydroxyls may be described by Maciel and not covered by HMDS as discussed above. Due to the small thickness of the surface modifying layer, there is little risk of gas release which could lead to contamination during fabrication of the device. Also, as shown in Table 2 by the "SC1" notation, each carrier and thin sheet was cleaned using the SC1 process prior to heat treatment or any subsequent HMDS treatment.

A comparison of Example 2b with Example 2a shows that the binding energy between the thin sheet and the carrier can be controlled by varying the number of surfaces comprising the surface modifying layer. Control of coupling energy can be used to control the coupling between two bonding surfaces. In addition, the comparison of Examples 2b-2e shows that the bonding energy of the surface can be controlled by changing the parameters of the heat treatment applied to the bonding surface before application of the surface modifying material. Again, heat treatment can be used to reduce the number of surface hydroxyls and thus control the covalent bonding degree, especially the covalent bonding degree at high temperature.

Other materials that can act in different ways to control the surface energy on the bonding surface can be used for the surface modification layer 30 to control room and high temperature bonding forces between the two surfaces. For example, one or both bonding surfaces may be modified by modifying a species, e. G., Hydroxyl, or a sterically hindered surface modifying layer to prevent the formation of strong permanent covalent bonds between the carrier and the thin sheet at elevated temperatures Reusable carrier can also be generated. One method of creating variable surface energy and coating the surface hydroxyl to prevent the formation of covalent bonds is the deposition of a plasma polymer film, for example a fluoropolymer film. The plasma polymerization may be carried out at atmospheric or subatmospheric or reduced pressure and at a source gas such as a fluorocarbon source (including CF4, CHF3, C2F6, C3F6, C2F2, CH3F, C4F8, chlorofluorocarbons or hydrochlorofluorocarbons) Such as alkanes (including methane, ethane, propane, butane), alkenes (including ethylene and propylene), alkynes (including acetylene), and aromatic compounds (including benzene and toluene) (DC or RF parallel plate, inductively coupled plasma (ICP) electron cyclotron resonance (ECR) downstream microwave or RF plasma). Plasma polymerization produces a layer of highly crosslinked material. Control of reaction conditions and source gases can be used to control film thickness, density, and chemical properties to tailor the functional groups to the desired application.

Figure 5 is a plot of the total (line) of a plasma polymerized fluoropolymer (PPFP) film deposited from a CF4-C4F8 mixture using an Oxford ICP380 etch tool (available from Oxford Instruments, Oxfordshire, UK) 502) surface energy (including polarity (line 504) and dispersion (line 506) components). The film was deposited on a sheet of Eagle XG® glass, and the spectroscopic ellipsometry showed that the film was 1-10 nm thick. As can be seen from Fig. 5, the glass carrier treated with a plasma polymerized fluoropolymer film containing less than 40% of C4F8 exhibits a surface energy of > 40 mJ / m &lt; ² &gt;, and is thinned by van der Waals or hydrogen bonding at room temperature Creating a controlled bond between the glass and the carrier. The facilitated bonding is observed initially when bonding the carrier and the thin glass at room temperature. That is, if a thin sheet is placed on a carrier and they are pressed together at one point, the wavefronts will travel across the entire carrier, but at a slower rate than that observed in the case of SC1-treated surfaces with no surface- Move. The controlled bonding is sufficient to withstand all standard FPD processes, including vacuum, wet, ultrasonic, and thermal processes below 600 ° C, i.e. the controlled bonding can be accomplished by 600 ° C machining tests without thin glass movement or delamination from the carrier . Debonding was achieved by peeling with a razor blade and / or Capton (TM) tape as described above. The process suitability of two different PPFP films (deposited as described above) is shown in Table 3. PPFP 1 of Example 3a was formed with C4F8 / (C4F8 + CF4) = 0, i.e., CF4 / H2, not C4F8, and PPFP2 of Example 3b was deposited with C4F8 / (C4F8 + CF4) = 0.38 . Both types of PPFP films have survived vacuum, SRD, 400 ° C and 600 ° C machining tests. However, after the ultrasonic cleaning of PPFP 2 of 20 minutes, interlayer delamination showing an insufficient adhesive force to withstand such processing is observed. Nonetheless, the surface modification layer of PPFP2 may be useful for some applications, such as when ultrasonic processing is not required.

<Table 3> - Process conformity test of PPFP surface modification layer

In Examples 3a and 3b above, each carrier and thin sheet was Eagle XG® glass, wherein the carrier was a 150 mm diameter SMF wafer 630 micrometers thick, and the thin sheet 100 square mm 100 micrometers thick. Due to the small thickness of the surface modifying layer, there is less risk of gas release which can lead to contamination during fabrication of the device. Also, since the surface modification layer is not seen to decompose again, there is less risk of gas evolution. In addition, as shown in Table 3, each thin sheet was cleaned using the SC1 process before heat treatment at 150 占 폚 under vacuum for one hour.

Other materials that can act in different ways to control surface energy can be used as the surface modification layer to control the room and high temperature bonding forces between the thin sheet and the carrier. For example, a bonding surface capable of producing a controlled bond can be produced by silane treatment of the glass carrier and / or glass thin sheet. The silane is selected to produce suitable surface energy, and to have sufficient thermal stability for application. The carrier or thin glass to be treated is cleaned by a process such as O2 plasma or UV-ozone, and SC1 or SC1 or standard clean (SC2 as known in the art) to interfere with the silane reacting with the surface silanol groups Organic materials, and other impurities (e.g., metals). Other chemicals based cleaning, such as HF, or H2SO4 cleaning chemicals, may also be used. The carrier or thin glass may be heated to control the surface hydroxyl concentration prior to silane application (as discussed above in relation to the surface modifying layer of HMDS) and / or may be subjected to silane condensation with the surface hydroxyl after silane application . The concentration of unreacted hydroxyl groups after silanization can be made sufficiently low to prevent permanent bonding between the thin glass and the carrier at a temperature of &gt; = 400 [deg.] C, i.e., to form a controlled bond. This approach is described below.

Example 4a

The glass carrier with O2 plasma and SC1 treated bonding surface was then treated with 1% dodecyltriethoxysilane (DDTS) in toluene and annealed at 150 DEG C under vacuum for 1 hour to complete the condensation. The DDTS treated surface showed a surface energy of 45 mJ / m ² . As shown in Table 4, a glass thin sheet (SC1 cleaned and heated at 400 占 폚 under vacuum for 1 hour) was bonded to a carrier bonding surface having a DDTS surface modification layer thereon. The article resisted wet and vacuum process tests but failed to withstand a thermal process above 400 ° C without bubble formation under the carrier due to thermal cracking of the silane. The thermal decomposition is carried out in the presence of all linear alkoxy and chloroalkylsilane R1 _x Si (OR2) _y (Cl) _z where x = 1-3 and y + z = 4-x, dimethyl-, and trimethyl-silane (x = 1 to _3, R1 = CH 3) is expected in the case of not including).

Example 4b

The glass carrier with O2 plasma and SC1 treated bonding surface was then treated with 1% 3,3,3, trifluoropropyltriethoxysilane (TFTS) in toluene and annealed at 150 ° C under vacuum for 1 hour Condensation was completed. The TFTS treated surface showed a surface energy of 47 mJ / m ² . As shown in Table 4, a glass thin sheet (SC1 cleaned and then heated at 400 占 폚 under vacuum for 1 hour) was bonded to a carrier bonding surface having a TFTS surface modification layer thereon. The article survived the vacuum, SRD, and 400 ° C process test without permanent bonding of the glass thin sheet to the glass carrier. However, the 600 ° C test resulted in bubble formation under the carrier due to thermal decomposition of the silane. This was not unexpected because of the limited thermal stability of the profiler. Although the sample failed the 600 &lt; 0 &gt; C test due to bubbling, the material and heat treatment of the sample may be used for some applications where bubbles and their side effects, e.g., reduced surface flatness, or increased surface wave form may be acceptable .

Example 4c

The glass carrier with O2 plasma and SC1 treated bonding surface was then treated with 1% phenyltriethoxysilane (PTS) in toluene and annealed at 200 &lt; 0 &gt; C under vacuum for 1 hour to complete the condensation. The surface treated with PTS showed a surface energy of 54 mJ / m ² . As shown in Table 4, a glass thin sheet (SC1 cleaned and then heated at 400 占 폚 under vacuum for 1 hour) was bonded to a carrier bonding surface having a PTS surface modification layer. The article resisted vacuum, SRD, and thermal processes below 600 ° C without permanent bonding of the glass carrier and the glass laminate.

Example 4d

The glass carrier with O2 plasma and SC1 treated bonding surface was then treated with 1% diphenyldiethoxysilane (DPDS) in toluene and annealed at 200 &lt; 0 &gt; C under vacuum for 1 hour to complete the condensation. The surface treated with DPDS showed a surface energy of 47 mJ / m ² . As shown in Table 4, a glass thin sheet (SC1 cleaned and then heated at 400 DEG C under vacuum for 1 hour) was bonded to a carrier bonding surface having a DPDS surface modification layer. The article resisted vacuum and SRD testing, as well as thermal processes below 600 ° C, without permanent bonding of the glass carrier to the glass thin sheet.

Example 4e

The glass carrier with O2 plasma and SC1 treated bonding surface was then treated with 1% 4-pentafluorophenyltriethoxysilane (PFPTS) in toluene and annealed at 200 &lt; 0 &gt; C under vacuum for 1 hour to complete the condensation . The surface treated with PFPTS showed a surface energy of 57 mJ / m ² . As shown in Table 4, a glass thin sheet (SC1 cleaned and then heated at 400 DEG C under vacuum for 1 hour) was bonded to a carrier bonding surface having a PFPTS surface modification layer. The article resisted vacuum and SRD testing, as well as thermal processes below 600 ° C, without permanent bonding of the glass carrier to the glass thin sheet.

<Table 4> - Process suitability test of silane surface modification layer

In Examples 4a to 4e, each carrier and thin sheet was Eagle XG® glass, where the carrier is a 150 mm diameter SMF wafer 630 micrometer thick, and the thin sheet is 100 mm square and 100 micrometer thick. The silane layer was a self-assembled monolayer (SAM) and was therefore less than about 2 nm thick. In this example, the SAM was produced using an aryl or alkyl nonpolar tail and an organosilane with a mono, di, or tri-alkoxy head group. They react with the silanol surface on glass to attach the organic functionalities directly. The weaker interactions between the nonpolar hair groups make up the organic layer. Due to the small thickness of the surface modifying layer, there is little risk of gas release which could lead to contamination during fabrication of the device. Also, since the surface modification layer was not seen to decompose again in Examples 4c, 4d, and 4e, there is less risk of gas release. Further, as shown in Table 4, each glass thin sheet was cleaned using the SC1 process before heat treatment at 400 占 폚 under vacuum for 1 hour.

As can be seen from the comparison of Examples 4a-4e, controlling the surface energy of the bonding surface to exceed 40 mJ / m ² to facilitate initial room-temperature bonding will resist the FPD process, It is not just a discussion about creating a controlled binding that will be removed. In particular, as can be seen from Examples 4a-4e, each carrier had a surface energy of greater than 40 mJ / m &lt; ² &gt;, which facilitated the initial room temperature bonding so that the article could withstand vacuum and SRD processing. However, Examples 4a and 4b did not pass the 600 &lt; 0 &gt; C processing test. As noted above, in certain applications, the bond may be processed (e.g., to a process designed to allow the article to be used) at or below high temperature (e.g., ≥400 ° C, ≥500 ° C, or ≥600 ° C, It is also important to withstand the point where it is not sufficient to hold the thin sheet and the carrier together without decomposition of the bond and also to control the covalent bonding occurring at such a high temperature so that there is no permanent bond between the thin sheet and the carrier.

The separation described above in Examples 4, 3 and 2 is carried out at room temperature without the addition of any additional heat or chemical energy to modify the bonding interface between the thin sheet and the carrier. The only energy input is the mechanical pulling and / or peeling force.

The materials described above in Examples 3 and 4 can be applied to a carrier, to a thin sheet, or to both a carrier and a thin sheet surface to be bonded together.

Purpose of Controlled Coupling

Reusable Carrier

One use of controlled bonding through a surface modification layer (including material and associated bonded surface heat treatment) is to provide reuse of the carrier in an article that has undergone a process requiring a temperature of &lt; RTI ID = 0.0 &gt; 600 C, &lt; will be. A surface modification layer (including material and bonded surface heat treatment), as illustrated by Examples 2e, 3a, 3b, 4c, 4d, and 4e, can be used to provide reuse of the carrier under these temperature conditions. In particular, these surface modification layers can be used to change the surface energy of the overlapping regions between the bond regions of the thin sheet and the carrier, thereby separating the entire thin sheet from the carrier after processing. The thin sheets may all be separated at one time, or they may be separated, for example, as in the case of first cleaning the carrier for reuse by removing the device manufactured on a portion of the thin sheet first and then removing the remaining portion You may. In the case of removing the entire thin sheet from the carrier, the carrier can be reused as it is simply by placing another thin sheet thereon. Alternatively, the carrier can be cleaned and the surface modification layer can be newly formed to have a thin sheet again. Because the surface modifying layer prevents permanent bonding of the carrier to the thin sheet, they can be used in processes where the temperature is &lt; RTI ID = 0.0 &gt; 600 C. &lt; / RTI &gt; Of course, these surface modification layers can control the bonding surface energy during processing at a temperature of &gt; = 600 [deg.] C, but they can also be used to fabricate thin sheet and carrier combinations that will withstand processing at lower temperatures, Can be used to control coupling in applications. In addition, if the thermal processing of the article does not exceed 400 ° C, the surface modification layer as exemplified by Examples 2c, 2d and 4b can also be used in this same manner.

To provide a controlled coupling area

A second use of controlled bonding through a surface modification layer (including materials and associated bonding surface heat treatment) is to provide a controlled bonding area between the glass carrier and the glass laminate. More particularly, using a surface modifying layer, a sufficient separating force can separate the thin sheet portion from the carrier without damaging the thin sheet or carrier caused by the bonding, but sufficient bonding force to hold the thin sheet against the carrier can be avoided, Lt; RTI ID = 0.0 &gt; a &lt; / RTI &gt; With reference to Fig. 6, the glass sheet 20 can be bonded to the glass carrier 10 by means of the bonded area 40. Fig. In the bonded region 40, the carrier 10 and the thin sheet 20 are covalently bonded together to act as a monolith. There is also a controlled engagement region 50 with a peripheral portion 52 where the carrier 10 and the thin sheet 20 are connected but can also be connected to each other even after processing at high temperature processing, Lt; / RTI &gt; Although 10 controlled regions 50 are shown in Fig. 6, one can provide any suitable number, including one. The surface modification layer 30 including the material and the bonding surface heat treatment as exemplified by the above Examples 2a, 2e, 3a, 3b, 4c, 4d and 4e is used to form the carrier 10 and the thin sheet 20 to provide a controlled engagement region 50 therebetween. In particular, these surface modification layers may be formed in the peripheral portion 52 of the controlled bonding region 50 on the carrier 10 or the thin sheet 20. The control between the carrier 10 and the thin sheet 20 in the area bonded to the periphery 52 is therefore controlled when the article 2 is processed at a high temperature to form a covalent bond in the bonding area 40 or during processing of the device. , Whereby the separating force can separate the thin sheet and the carrier from the area (without breakage damage to the thin sheet or the carrier), but the thin sheet and the carrier will not be delaminated during processing, including ultrasonic processing will be. Thus, the controlled combination of the present invention provided by the surface modification layer and any associated heat treatment can improve on the carrier concept in US '727. In particular, carriers of US '727 with bonded peripheral and non-bonded center regions have been shown to withstand FPD processes including high temperature temperature processes of about &lt; RTI ID = 0.0 &gt; 600 C, &lt; / RTI &gt; but ultrasonic processes, such as wet scrubbing and resist strip processes, it's difficult. In particular, pressure waves in solution have been shown to induce resonance in thin glass of non-bonding regions, because there is little or no adhesive force to bond the thin glass to the carrier in the non-bonding region (the non- 727). Standing waves can be formed in thin glass where these waves can create vibrations that can lead to the destruction of thin glass at the interface between bonded and unbonded areas when ultrasonic agitation is of sufficient strength. This problem can be eliminated by minimizing the spacing between the thin glass and the carrier, and by providing sufficient bonding in these areas 50, or controlled bonding between the carrier 20 and the thin glass 10. [ The surface modification layer of the bonding surface (including the materials exemplified by Examples 2a, 2e, 3a, 3b, 4c, 4d and 4e and any associated heat treatment) Providing sufficient coupling between the thin layer 20 and the carrier 10 to avoid undue vibrations.

The portion of the thin sheet 20 in the peripheral portion 52 is then removed from the carrier 10 after processing and after separating the thin sheet along the peripheral portion 57, while the object portion 56 with the peripheral portion 57 is being removed. As shown in FIG. Because the surface modifying layer controls the binding energy to prevent permanent bonding of the carrier to the thin sheet, they can be used in processes where the temperature is &lt; RTI ID = 0.0 &gt; 600 C. &lt; / RTI &gt; Of course, these surface modifying layers can control the bonding surface energy during processing at temperatures of &gt; = 600 [deg.] C, but they can also be used to fabricate thin sheet and carrier combinations that will withstand processing at lower temperatures, It can be used in applications. In addition, if the thermal processing of the article does not exceed 400 ° C, the surface modification layer as exemplified by Examples 2c, 2d and 4b can also be applied in this same manner - in some cases, according to other process requirements - Can be used to control energy.

To provide a binding region

A third use of controlled bonding through a surface modification layer (including material and any associated bonding surface heat treatment) is to provide a bonding area between the glass carrier and the glass thin sheet. With reference to Fig. 6, the glass sheet 20 can be bonded to the glass carrier 10 by means of the bonded area 40. Fig.

In one embodiment of the third application, in the bonded region 40, the carrier 10 and the thin sheet 20 may be covalently bonded together to act as a monolithic. There is also a controlled engagement region 50 with a peripheral portion 52 wherein the carrier 10 and the thin sheet 20 are sufficient to withstand machining, but they can be machined at a high temperature, for example, &lt; RTI ID = 0.0 & And are later coupled to each other to permit separation of the thin sheet from the carrier. Thus, the surface modification layer 30 (including material and bonded surface heat treatment) as exemplified by Examples 1a, 1b, 1c, 2b, 2c, 2d, 4a and 4b above, And may provide a bond region 40 between the thin sheets 20. In particular, these surface modification layers and heat treatment can be formed on the outside of the peripheral portion 52 of the controlled bonding region 50 on the carrier 10 or the thin sheet 20. Thus, when the article 2 is processed at a high temperature or processed at high temperature to form a covalent bond, the carrier and thin sheet 20 are bonded together in the bond region 40 outside the region bonded to the periphery 52 They will be joined together. If it is desired to dice the thin sheet 20 and the carrier 10 while the target portion 56 with the peripheral portion 57 is being removed, then these surface modification layers and heat treatment may be carried out using a thin sheet 20 The article may be separated along line 5 because it is covalently bonded to carrier 10 and as it acts as a monolayer in this region. Because the surface modification layer provides permanent covalent bonding of the carrier to the thin sheet, they can be used in processes where the temperature is &lt; RTI ID = 0.0 &gt; 600 C. &lt; / RTI &gt; Also, the surface modification layer, as exemplified by the material and heat treatment in Example 4a, is also used in this same manner if the thermal processing of the article, or the initial formation of the bonding region 40 is &gt; = 400 ° C or less than 600 ° C Can be used.

In a second embodiment of the third application, in the bonded region 40, the carrier 10 and the thin sheet 20 may be bonded together by controlled bonding through the various surface modification layers described above. There is also a controlled engagement region 50 with a peripheral portion 52 wherein the carrier 10 and the thin sheet 20 are sufficient to withstand machining but are not subjected to high temperature processing, And are coupled to each other to allow separation of the thin sheet from the carrier even after processing. Thus, if it is desired that processing be performed at a temperature of 600 ° C or below, and it is desirable not to have a permanent or covalent bond in the region 40, it is preferred that the process as illustrated by Examples 2e, 3a, 3b, 4c, 4d and 4e The same surface modification layer 30 (including material and bonding surface heat treatment) can be used to provide a bond region 40 between the carrier 10 and the thin sheet 20. In particular, these surface modification layers and thermal treatments can be formed outside the peripheral portion 52 of the controlled bonding region 50 and can be formed on the carrier 10 or on the thin sheet 20. The controlled bonding region 50 may be formed of the same or different surface modification layer as that formed in the bonding region 40. Alternatively, if it is desired to perform the processing only at a temperature of 400 DEG C or lower and it is desirable not to have a permanent or covalent bond in the region 40, the above Examples 2c, 2d, 2e, 3a, 3b, 4b, 4c, The surface modification layer 30 (including material and bonding surface heat treatment) as illustrated by Figures 4d and 4e can be used to provide the bonding region 40 between the carrier 10 and the thin sheet 20.

Instead of controlled bonding in region 50, there may be a non-bonding region in region 50, where the non-bonding region may be an area having increased surface roughness as described in US '727, or alternatively, A surface modification layer as exemplified by Example 2a can be provided.

For bulk annealing or bulk processing

A fourth application of the above-described method of controlling bonding is for bulk annealing of a stack of glass sheets. Annealing is a thermal process to achieve compression of the glass. Compression involves reheating the glass body to a temperature below the glass softening point, but above the maximum temperature leading to subsequent processing steps. This achieves structural rearrangement and dimensional relaxation in glass prior to subsequent processing rather than during subsequent processing. Annealing prior to subsequent processing may maintain accurate orientation and / or flatness in the glass body during subsequent processing, such as in the manufacture of flat panel display devices where the structure of many layers must be aligned with very tight tolerances, . When the glass is compressed in one high temperature process, the layer of the structure deposited on the glass prior to the high temperature process can not be precisely aligned to the layer of the deposited structure after the high temperature process.

Compressing the glass sheet into a stack is economically attractive. However, this made it possible to sandwich or separate adjacent sheets to avoid stickiness. At the same time, it is advantageous to keep the sheet very flat and optically-characteristic, or have a very clean surface finish. Also, in the case of certain stacks of glass sheets, for example sheets with small surface areas, glass sheets can "glue" together during the annealing process and allow them to move easily without separation as a unit, but after the annealing process It may be advantageous to be able to separate them easily from one another and to use the sheets individually. Alternatively, one or more of the glass sheets can be permanently bonded together while preventing the selected one of the glass sheets from being permanently bonded to each other, while at the same time allowing the other one of the glass sheets, or portions thereof, It may be advantageous to anneal the stack of layers. As a further alternative, it may be advantageous to laminate the glass sheets in bulk to selectively permanently bond the peripheral portions of selected adjacent pairs of sheets in the stack. The bulk annealing and / or selective bonding can be achieved using the above-described method of controlling bonding between glass sheets. To control bonding at any particular interface between adjacent sheets, a surface modification layer may be used on at least one of the major surfaces facing that interface.

One embodiment of a stack of glass sheets suitable for bulk annealing or bulk permanent bonding at selected areas (e.g., around the periphery) will be described with reference to FIGS. 7 and 8. 7 is a schematic side view of stack 760 of glass sheets 770-772, and FIG. 8 is an exploded view thereof for the purpose of further explanation.

The stack of glass sheets 760 may include a glass sheet 770-772 and a surface modification layer 790 that controls bonding between the glass sheets 770-772. The stack 760 may also include cover sheets 780 and 781 disposed at the top and bottom of the stack and may include a surface modification layer 790 between the cover and the adjacent glass sheet.

Each glass sheet 770-772 includes a first major surface 776 and a second major surface 778, as shown in FIG. The glass sheet can be made of any suitable glass material, for example, an alumino-silicate glass, a boro-silicate glass, or an aluminoborosilicate glass. Further, the glass may be alkali-containing, or alkali-free and may be unique. Each glass sheet 770-772 may have the same composition, or the sheet may have a different composition. In addition, the glass sheet may have any suitable type. That is, for example, the glass sheets 770-772 may be all carriers as described above, or they may all be thin sheets as described above, or alternatively may be carriers and thin sheets. It is advantageous to have a stack of carriers and a separate stack of thin sheets when the bulk annealing requires different time-temperature cycling for the carrier than for the thinner sheet. Alternatively, it may be desirable to have a stack comprising a carrier and a thin sheet alternately, using the right surface modification layer material and arrangement, whereby the target pair of carrier and thin sheet, i.e., those forming the article, But also to preserve the ability to simultaneously separate adjacent articles from each other. Still further, any suitable number of glass sheets may be present in the stack. That is, although only three glass sheets 770-772 are shown in Figs. 7 and 8, any suitable number of glass sheets may be included in stack 760. Fig.

In any particular stack 760, any one glass sheet may not include a surface modification layer, or may include one surface modification layer, or two surface modification layers. For example, as shown in FIG. 8, the sheet 770 does not include a surface modification layer, and the sheet 771 includes one surface modification layer 790 on its second major surface 778 And the sheet 772 includes two surface modification layers 790, one surface modification layer being on each of its major surfaces 776, 778.

Cover sheet 780, 781 can be any material that will adequately withstand a time-temperature cycle for a given process (in terms of time and temperature, as well as other appropriate considerations such as, for example, gas release) have. Advantageously, the cover sheet can be made of the same material as the glass sheet being processed. If the cover sheets 780 and 781 are present and have a material that will adversely associate with the glass sheet when attaching the stack over a given time-temperature cycle, the surface modification layer 790 may be disposed between the glass sheet 771 and the cover Or between the glass sheet 772 and the cover sheet 780, as appropriate. When present between the cover and the glass sheet, the surface modification layer can be on the cover (as shown by the cover 781 and the adjacent sheet 771), on the glass sheet (cover 780 and sheet 772), or on both the cover and the adjacent sheet (not shown). Alternatively, if cover sheets 780 and 781 are present but have a material that will not engage adjacent sheets 772 and 772, surface modification layer 790 need not be present between them.

There is an interface between adjacent sheets in the stack. For example, an interface is defined between adjacent ones of the glass sheets 770-772, that is, an interface 791 exists between the sheet 770 and the sheet 771, and the sheet 770 and the sheet 772). &Lt; / RTI &gt; In addition, when the cover sheets 780 and 781 are present, not only the interface 793 exists between the cover 781 and the sheet 771 but also the interface 794 exists between the sheet 772 and the cover 780 do.

The surface modification layer 790 can be used to control bonding at a given interface 791, 792 between adjacent glass sheets or at a given interface 793, 794 between the glass sheet and the cover sheet. For example, as shown, at each of the interfaces 791 and 792, there is a surface modification layer 790 on at least one of the major surfaces facing that interface. For example, in the case of interface 791, the second major surface 778 of the glass sheet 771 includes a surface modification layer 790 to control the coupling between the sheet 771 and the adjacent sheet 770 . Although not shown, the first major surface 776 of the sheet 770 may also include a surface modification layer 790 thereon to control engagement with the sheet 771, i. E., To face any particular interface There may be a surface modification layer on each major surface.

It is to be understood that at any given interface 791-794 a particular surface modification layer 790 (and any associated surface modification process - e.g., thermal treatment for a particular surface, or surface modification, The surface heat treatment of the layer capable of contacting the surface) allows the major surfaces 776 and 778 facing that particular interface 791-794 to control the coupling between adjacent sheets and thereby apply to the stack 760 Can be selected to achieve the desired result for a given time-temperature cycle.

If it is desired to bulk anneal the stack of glass sheets 770-772 at a temperature of 400 DEG C or lower and to separate each glass sheet from each other after the annealing process, then at any particular interface, for example at interface 791 Could be controlled using materials according to any of Examples 2a, 2c, 2d, 2e, 3a, 3b, or 4b-4e, with any associated surface preparation. More specifically, the first surface 776 of the sheet 770 will be treated as "thin glass" in Tables 2-4, while the second surface 778 of the sheet 771 will be treated as " "And vice versa. A suitable time-temperature cycle, with a temperature below 400 DEG C, is then selected based on the desired degree of compression, the number of sheets in the stack, as well as the size and thickness of the sheet, to achieve the required time-temperature throughout the stack I could.

Similarly, if it is desired to bulk anneal the stack of glass sheets 770-772 at a temperature of 600 DEG C or less and to separate each glass sheet from each other after the annealing process, then any particular interface, 791 could be controlled using materials according to any of Examples 2a, 2e, 3a, 3b, 4c, 4d, 4e, along with any associated surface fabrication. More specifically, the first surface 776 of the sheet 770 will be treated as "thin glass" in Tables 2-4, while the second surface 778 of the sheet 771 will be treated as " "And vice versa. A suitable time-temperature cycle, with a temperature below 600 ° C, is then selected based on the desired degree of compression, the number of sheets in the stack, as well as the size and thickness of the sheet, to achieve the required time-temperature throughout the stack I could.

In addition, by appropriately configuring the stack of sheets and the surface modification layer between each pair of these, bulk annealing and bulk article formation can be performed. If it is desired to bulk anneal the stack of glass sheets 770-772 at temperatures below 400 ° C and then covalently bond the pairs of adjacent sheets to each other in bulk to form the article 2, And the associated surface preparation. For example, at the periphery (or in another preferred bonding region 40), the bond at the interface between the pair of glass sheets, for example sheets 770 and 771, which will be formed into article 2, ) With any associated surface treatment around the perimeter of sheets 770, 771 (or other preferred bonding areas 40) with the material according to any of embodiments 2c, 2d, 4b; And (ii) depositing a material according to any one of embodiments 2a, 2e, 3a, 3b, 4c, 4d and 4e on the interior area of sheets 770, 771 (i.e., Or in combination with any associated surface treatment, in a desired controlled binding region 50 where separation of another sheet from one sheet is desirable). In this case, the device fabrication in the subsequently controlled bonding region 50 could then be carried out at a temperature of less than or equal to 600 ° C.

Materials and heat treatments could be selected appropriately for compatibility with each other. For example, any material (2c, 2d, or 4b) could be used for the bonding region 40 with the material according to Example 2a for the controlled bonding region. Alternatively, the thermal treatment for the bonded area and the controlled bonded area could be suitably controlled to minimize the effect of heat treatment in one area, which adversely affects the desired degree of bonding in the adjacent areas.

After appropriately selecting the surface modification layer 790 and the associated thermal treatment for the glass sheet in the stack, such sheets are suitably arranged in a stack and heated to below 400 DEG C to bulk anneal all sheets into a stack, without them being permanently bonded to each other Could. The stack could then be heated below 600 ° C to form a covalent bond of a pair of adjacent sheets in the desired bonding region to form the article 2 with the bond region and the pattern of the controlled bond region. Coupling at the interface between a pair of sheets to be covalently joined by the coupling region 40 to form the article 2 and another pair of such sheets to form the separated but adjacent article 2, 2a, 2e, 3a, 3b, 4c, 4d, 4e and associated heat treatment, so that adjacent articles 2 will not be covalently bonded to each other. In this same manner of controlling the engagement between adjacent articles, the bond between the article and any cover sheet present in the stack could be controlled.

Additionally, similar to the above, the article 2 can be formed from the stack 760 in a bulk without annealing the same stack 760 in advance. Alternatively, the sheet could be constructed as a stack for the desired controlled bond and be separately annealed, or annealed to another stack and separated therefrom, prior to bulk manufacture of the article. Bulk annealing is simply omitted in the manner described-just before bulk-annealing and immediately prior to bulking the article from the same stack.

Although the only way of controlling the bonding at the interface 791 has been described in detail above, it is of course of course possible that at the interface 792, or for any other interface that may be present in a particular stack, As in the case, or in the case where there is a cover sheet to be bonded undesirably to the glass sheet. It should also be noted that although the same way of controlling bonding can be used at any interfaces 791, 792, 793, 794 present, it is also possible to use the same or different It can also be used at other interfaces to produce results.

In the above process of bulk annealing or forming the article 2 into a bulk, HMDS is used as a material to control bonding at the interface, and when the HMDS is exposed to the outer periphery of the stack, A heating of greater than about 400 [deg.] C in an oxygen-free atmosphere should be performed. That is, when HMDS is exposed to the amount of oxygen in the atmosphere sufficient to oxidize HMDS (at a temperature greater than about 400 DEG C), the bond in any such region where HMDS is oxidized will be a covalent bond between adjacent glass sheets will be. Other alkyl hydrocarbon silanes, such as ethyl, propyl, butyl, or stearyl silanes, can likewise be affected by exposure to higher temperatures, e. Similarly, if another material is used for the surface modification layer, the environment for bulk annealing should be chosen such that the material does not decompose during the time-temperature cycle of annealing. As used herein, anoxic oxygen can mean an oxygen concentration of less than 1000 volume ppm, more preferably less than 100 volume ppm.

Once the stack of sheets is bulk annealed, each sheet can be separated from the stack. Each sheet may be treated to remove surface modification layer 790 (e.g., by oxygen plasma heating in an oxygen environment at a temperature of? 400 ° C, or by chemical oxidation, SC1, or SC2). Each sheet can be used as an electronic device, for example an OLED, FPD, or PV device substrate, depending on the purpose.

The above-described method, or bulk processing, of bulk annealing has the advantage of maintaining a clean sheet surface in an economical manner. More particularly, the sheet need not be kept in a clean environment from start to finish, as in a clean-room annealing rare. Instead, the stack can be formed in a clean environment without contamination of the sheet surface with the particles because there is no fluid flow between the sheets, and then processed in a standard annealing race (i.e., where cleanliness is not controlled). Thus, the sheet surface is protected from the environment in which the stack of sheets is annealed. After annealing, the stack of sheets can be easily transported to additional process areas (at the same or different facility) because the sheets remain somewhat adhesive but remain separable from each other without damaging the sheet when sufficient force is applied have. That is, a glass manufacturer can assemble and anneal a stack of glass sheets (for example), and then transport the sheets as a stack, the sheets are stuck together during shipping (without fear of their being separated during transport) The sheets can be separated from the stack by the consumer who can use the sheets individually or in smaller groups. Once separation is desired, the stack of sheets may be reworked in a clean environment (after washing the stack if necessary).

Examples of bulk annealing

A glass substrate was used as it was obtained from the fusion drawing process. The composition of the drawn fusion glasses was (in mol%): SiO2 (67.7), Al2O3 (11.0), B2O3 (9.8), CaO (8.7), MgO (2.3) and SrO (0.5). Seven (7), 0.7 mm thick x 150 mm diameter, fused pulled glass substrates were patterned by lithographic method with 200 nm depth starting / attaching using HF. This (2) nm plasma-deposited fluoropolymer as a surface modification layer was coated on all bonding surfaces of all glass substrates, i.e. each surface of the substrate facing another substrate, resulting in the formation of each sheet surface The surface energy was approximately 35 m ² J / m ² . Each of the seven coated glass substrates was put together to form a single thick substrate (referred to as a "glass stack"). The glass stack was ramped from 30 DEG C to 590 DEG C over a period of 15 minutes in a nitrogen fired tubular furnace, held at 590 DEG C for 30 minutes, then ramped down to about 230 DEG C over a period of 50 minutes, And cooled to room temperature of about 30 < 0 &gt; C to within about 10 minutes and annealed. After cooling, the substrate was removed from the furnace and easily separated into individual sheets using a razor wedge (i.e., the sample was not permanently bonded, either wholly or locally). Compression was measured on each individual substrate by comparing the glass origin to an un-annealed quartz reference. Each substrate was found to have compressed about 185 ppm. As each sample, two of the substrates (not stacked together) were subjected to a second annealing cycle as described above (590 [deg.] C / hold for 30 minutes). Compression was again measured and the substrate was found to further compress below 10 ppm (actually 0 to 2.5 ppm) due to secondary heat treatment (change in glass dimensions after the second heat treatment - compared to the original glass dimensions - Minus the change in glass dimensions after the first heat treatment). Thus, the present inventors have found that individual glass sheets can be coated, laminated and heat treated at high temperatures to achieve compression, cooling, separation into individual sheets, and after the second heat treatment a dimension of <10 ppm, even <5 ppm (As compared to their size change after the first heat treatment).

Although the furnace has been purged with nitrogen in the annealing examples described above, the annealing furnace may also contain air, argon, oxygen, CO ₂ , or combinations thereof, depending on the annealing temperature and the stability of the surface modification layer material at such temperature in the particular environment And other gases.

Also, although not shown, the glass may be annealed in the form of a spool instead of the sheet. That is, a suitable surface modification layer may be formed on one or both sides of the glass ribbon, and the ribbon may then be rolled. The entire roll can be subjected to the same treatment as mentioned above for the sheet, so that the glass of the entire spool will be annealed rather than adhering to one adjacent rap of the glass. As soon as the surface modification layer is unfolded, it can be removed by any suitable process.

Gas release

The polymeric adhesives used in typical wafer bonding applications are typically 10-100 micrometers thick and lose about 5% of their mass at or near its temperature limit. For such materials originating from thick polymer films, it is easy to quantify the amount of mass loss, or gas release, by mass-spectrometry. On the other hand, it is more difficult to measure gas emissions by a thin surface treatment of about 10 nm thickness or less, for example from the plasma polymer or self-assembled monolayer surface modification layer described above, as well as by a thin layer of pyrolyzed silicone oil. For such materials, mass-spectrometry is not sufficiently sensitive. However, there are many different ways to measure gaseous emissions.

The first method of measuring a small amount of gas release will be described with reference to Figure 9, based on surface energy measurements. To perform this test, a setting as shown in Fig. 9 can be used. A first substrate, or carrier 900 with a surface modification layer to be tested on it, provides a surface 902, i.e. the surface modification layer corresponds to the composition and thickness of the surface modification layer 30 to be tested. The second substrate, or cover 910, is positioned such that its surface 912 abuts the surface 902 of the carrier 900, but is not in contact therewith. Surface 912 is the surface of the uncoated surface, i.e., the surface of the substrate from which the cover is made. The spacers 920 are located at various points between the carrier 900 and the cover 910 and keep them in spaced relation to each other. The spacers 920 are thick enough to separate the cover 910 from the carrier 900 to allow movement of the material from one to the other but minimize the amount of contamination from the chamber atmosphere at the surfaces 902 and 912 during testing It should be thin enough. The carrier 900, the spacer 920, and the cover 910 together form the test article 901.

Before assembling the test article 901, the surface energy of the top surface 912 is measured as is the surface energy of the surface of the carrier 900 having the surface 902, i.e., the surface modification layer provided thereon. Both the surface energy, polarity and dispersed component as shown in Fig. The theoretical model developed by S. Wu (1971) was applied to three test fluids; Water, diiodomethane and hexadecane. &Lt; tb &gt; &lt; TABLE &gt; (S. Wu, J. Polym. Sci. C, 34, 19, 1971).

After assembly, the test article 901 is placed in a heating chamber 930 and heated for a time-temperature cycle. Heating is performed at atmospheric pressure and under flowing N2 gas, i.e. N2 gas flowing in the direction of arrow 940 at a rate of 2 standard liters per minute.

During the heating cycle, changes in the surface 902 (including, for example, evaporation, pyrolysis, decomposition, polymerization, reaction with the carrier, and changes to the surface modification layer due to dehydration) . The change in surface energy of the surface 902 by itself does not necessarily mean that the surface modification layer has been vented, but it exhibits general instability of the material at that temperature because its properties are changing, for example, due to the mechanisms mentioned above . Therefore, the smaller the change in the surface energy of the surface 902, the more stable the surface modification layer. On the other hand, due to the proximity of the surface 912 to the surface 902, any material released from the surface 902 will be collected on the surface 912 and will change the surface energy of the surface 912 will be. Thus, a change in the surface energy of the surface 912 results in a proxy for gas release of the surface modification layer present on the surface 902.

Thus, a test for gas release uses a change in the surface energy of the cover surface 912. Specifically, if there is a change in surface energy of surface 912 of? 10 mJ / m ² , then there is a gas release. The change in surface energy of this scale is consistent with the contamination that can lead to loss or degradation of film adhesion in material properties and device performance. Changes in surface energy of ≤ 5 mJ / m ² are close to non-uniformity of surface energy and repeatability of surface energy measurements. The small change corresponds to a minimum gas release.

10, the carrier 900, the cover 910, and the spacer 920 are made of Eagle XG glass available from Corning Incorporated of Corning, NY, an alkali-free alumina- Boro-silicate display-grade glass, but that need not be the case. The carrier 900 and the cover 910 were 150 mm in diameter and 0.63 mm thick. In general, the carrier 910 and the cover 920 will each be made of the same material as the carrier 10 and the thin sheet 20, for which a gas release test is desired. During this test, the silicon spacers were 0.63 mm thick, 2 mm wide, and 8 cm long, thereby forming a gap of 0.63 mm between the surfaces 902 and 912. During this test, the chamber 930 is circulated at room temperature to the test limit temperature at a rate of 9.2 캜 / min and maintained at the test limit temperature for various times as indicated in the graph as "annealing time" RTI ID = 0.0 &gt; MPT-RTP600s &lt; / RTI &gt; After the oven was cooled to 200 ° C, the test article was removed and the test article was cooled to room temperature before the surface energies of each surface 902 and 912 were again measured. Thus, for example, for material # 1, the data were collected as follows using data on the change in cover surface energy, line 1003, as tested at a critical temperature of 450 캜. The data point at 0 min represents a surface energy of 75 mJ / m ² (milli-lines per square meter) and is the surface energy of the manganese, meaning that no time-temperature cycle has yet been performed. The data point at 1 minute represents the surface energy as measured after a time-temperature cycle performed as follows: (having material # 1 used as the surface modification layer in carrier 900 to provide surface 902) ) Placing the article 901 in the heating chamber 930 at room temperature and at atmospheric pressure; The chamber is heated to a test-critical temperature of 450 占 폚 at a rate of 9.2 占 폚 / min and maintained at a test-critical temperature of 450 占 폚 for one minute under a flow of 2 standard liters / minute of N2 gas; The chamber is then allowed to cool to 300 DEG C at a rate of 1 DEG C / minute, and then the article 901 is removed from the chamber 930; The article is then allowed to cool to room temperature (without the atmosphere in which N2 flows); The surface energy of surface 912 was then measured and plotted on line 1003 as a point for one minute. Subsequently, the remaining data points for material # 1 (lines 1003 and 1004) as well as material # 2 (lines 1203 and 1204), material # 3 (lines 1303 and 1304) (Lines 1403 and 1404), material # 5 (lines 1503 and 1504), and material # 6 (lines 1603 and 1604) , Or in a similar manner corresponding to the holding time at 600 &lt; 0 &gt; C. 1201, 1202, 1301, 1302, 1401, 1402, 1501, 1502, 1601, 1602, and 1503 representing the surface energy of the surface 902 for the corresponding surface modification layer material (materials # 1-6) And 1602 were determined in a similar manner, except that the surface energy of surface 902 was measured after each time-temperature cycle.

The assembly process, and the time-temperature cycle, were performed on six different materials as described below, and the results are shown graphically in FIG. Of the six materials, materials # 1-4 correspond to the surface modification layer materials described above. Materials # 5 and # 6 are comparative examples.

Material # 1 is a CHF3-CF4 plasma polymerized fluoropolymer. This material is consistent with the surface modification layer in Example 3b above. As shown in FIG. 10, lines 1001 and 1002 show that the surface energy of the carrier was not significantly changed. Therefore, the material is very stable at a temperature of 450 ° C to 600 ° C. Also, as indicated by lines 1003 and 1004, the surface energy of the cover did not change significantly, i.e., the change was? 5 mJ / m ² . Thus, there was no gas release associated with the material at 450 ° C to 600 ° C.

Material # 2 is phenyl silane, which is a self-assembled monolayer (SAM) deposited from a 1% toluene solution of phenyltriethoxysilane and cured at 190 占 폚 for 30 minutes in a vacuum oven. This material is consistent with the surface modification layer of Example 4c above. As shown in Fig. 10, lines 1201 and 1202 show some change in the surface energy of the carrier. As mentioned above, this represents a slight change in the surface modification layer and, by comparison, material # 2 is somewhat less stable than material # 1. However, as noted by lines 1203 and 1204, the change in the surface energy of the carrier is? 5 mJ / m ² , showing that changes to the surface modification layer did not cause gas release.

Material # 3 is pentafluorophenylsilane, which is a SAM deposited from a 1% toluene solution of pentafluorophenyltriethoxysilane and cured at 190 占 폚 for 30 minutes in a vacuum oven. This material is consistent with the surface modification layer of Example 4e above. As shown in FIG. 10, lines 1301 and 1302 show some change in the surface energy of the carrier. As mentioned above, this represents a slight change in the surface modification layer and, by comparison, material # 3 is somewhat less stable than material # 1. However, as noted by lines 1303 and 1304, the change in the surface energy of the carrier is? 5 mJ / m ² , showing that changes to the surface modification layer did not cause gas release.

Material # 4 is hexamethyldisilazane (HMDS) deposited from steam at 140 ° C in a YES HMDS oven. The material corresponds to the surface modification layer of Example 2b in Table 2 above. As shown in FIG. 10, lines 1401 and 1402 show some change in the surface energy of the carrier. As mentioned above, this represents a slight change in the surface modification layer and, by comparison, material # 4 is somewhat less stable than material # 1. In addition, the change in the surface energy of the carrier for substance # 4 is greater than that of any of substances # 2 and # 3, and, by comparison, indicates that substance # 4 is somewhat less stable than substances # 2 and # 3. However, as noted by lines 1403 and 1404, the change in the surface energy of the carrier is? 5 mJ / m &lt; ² &gt;, and a change to the surface modification layer does not cause gas release . However, this is consistent with the way HMDS releases gas. That is, the HMDS emits ammonia and water that does not affect the surface energy of the cover and can not affect some electronics manufacturing equipment and / or processing. On the other hand, if the product of the gas release is trapped between the thin sheet and the carrier, there may be other problems as mentioned below in connection with the secondary gas release test.

Material # 5 is glycidoxypropyl silane, which is a SAM deposited from a 1% toluene solution of glycidoxypropyltriethoxysilane and cured at 190 캜 for 30 minutes in a vacuum oven. This is a comparative example material. As indicated by lines 1501 and 1502, there is a relatively small change in the surface energy of the carrier, but there is a significant change in the surface energy of the cover as indicated by lines 1503 and 1504. See FIG. That is, material # 5 was relatively stable at the carrier surface, but actually emitted a significant amount of material on the cover surface, and the cover surface energy varied by? 10 mJ / m ² . The surface energy is at 10 mJ / m ² at the end of 10 minutes at 600 ° C, but the change over time exceeds 10 mJ / m ² . For example, refer to data points at 1 and 5 minutes. Though not wishing to be bound by theory, a slight increase in surface energy from 5 to 10 minutes is likely to cause some of the gaseous released material to break down and fall off the cover surface.

Material # 6 was prepared by dispensing 5 ml Dow Corning 704 diffusion pump oil tetramethyl tetraphenyl trisiloxane (available from Dow Corning) onto the carrier and placing it in a 500 ° C hot plate for 8 minutes in air Coated silicon coating DC704. Completion of the preparation of the sample is known by the termination of visible smoke. After the sample was prepared by the above method, the gas release test described above was carried out. This is a comparative example material. As shown in FIG. 10, lines 1601 and 1602 show some change in the surface energy of the carrier. As mentioned above, this represents a slight change in the surface modification layer and, by comparison, material # 6 is less stable than material # 1. Also, as noted by lines 1603 and 1604, the change in the surface energy of the carrier is &gt; = 10 mJ / m &lt; ² &gt; and represents significant gas evolution. More specifically, at a test-limit temperature of 450 캜, the data points for 10 minutes represent a reduction in surface energy of about 15 mJ / m ² , and for data points at 1 and 5 minutes, Respectively. Similarly, the decrease in the surface energy of the cover, which is the change in the surface energy of the cover during circulation at the 600 ° C test-limit temperature, was about 25 mJ / m ² at 10 minutes data point, somewhat larger at 5 minutes, Min. Overall, there was a significant amount of gas release in the case of the material over the entire range of the test.

Significantly, in the case of material # 1-4, the surface energy over the time-temperature cycle remains at the surface energy that corresponds to the surface energy of the cover glass surface, that is, there is no collected material released from the carrier surface Lt; / RTI &gt; In the case of material # 4, the manner in which the carrier and the thin sheet surface are produced, as mentioned in connection with Table 2, depends on whether the article (the thin sheet bonded together with the carrier through the surface modification layer) There is a big difference. Thus, although the embodiment of material # 4 shown in Figure 10 is not capable of releasing gases, the material may or may not withstand a 400 ° C or 600 ° C test as mentioned in connection with the discussion of Table 2.

A second way to measure a small amount of gaseous emissions is by reference to the assembled article, that is, a thin sheet is bonded to the carrier through the surface modification layer and the change in percent bubble area is used to determine gas release. That is, while heating the article, the bubbles formed between the carrier and the thin sheet indicate gas evolution of the surface modification layer. As mentioned above with respect to the primary gas release test, it is difficult to measure the gas release of a very thin surface modification layer. In this secondary test, gas release beneath the thin sheet can be limited by the strong adhesion between the thin sheet and the carrier. Nonetheless, layers with a thickness of? 10 nm (e.g., plasma polymerized materials, SAM, and pyrolyzed silicone oil surface treatment) can continue to generate bubbles during thermal processing, despite their less absolute mass loss have. And the creation of bubbles between the thin sheet and the carrier can cause problems associated with pattern generation, photolithographic processing, and / or orientation during device processing on the thin sheet. In addition, bubbling at the boundaries of the bonded area between the thin sheet and the carrier can cause problems associated with the process fluid from one process that contaminates the downstream process. The change in% bubble area of &gt; = 5 indicating gas evolution is significant and undesirable. On the other hand, the change in% bubble area of ≤ 1 is not significant and is an indication that there is no gas release.

The average bubble area of a thin glass bonded by passive bonding in a Class 1000 clean room is 1%. The% bubble in the combined carrier is a function of the carrier, the thin glass sheet, and the cleanliness of the surface preparation. Since these initial defects serve as nucleation sites for bubble growth after heat treatment, any change in the bubble area of less than 1% during thermal processing is within the variability of sample preparation. To perform the test, a primary scan image of a region where a thin sheet and carrier were combined immediately after bonding was made using a commercially available desktop scanner (Epson Expression 10000XL port) with a perspective view unit. We scanned a portion using standard Epson software and using 508 dpi (50 micrometers per pixel) and 24 bit RGB. The image processing software first stitches the images of the different sections of the sample into a single image and, if necessary, produces the image by removing the scanner artifacts (using a calibrated reference scan performed without a sample in the scanner). The combined regions are then analyzed using standard imaging techniques, such as aliasing, hole filling, erosion / expansion, and blob analysis. The newer Epson Expression 11000XL port can also be used in a similar way. In the transfer mode, the bubble in the coupling region can be seen in the scan image and the value for the bubble region can be determined. The bubble area is then compared to the total area of engagement (i. E., The total overlap area between the thin sheet and the carrier) to calculate the% area of the bubble in the area of engagement for the total area of engagement. The samples are then heat treated in a MPT-RTP600s rapid thermal processing system at a test-critical temperature of 300 DEG C, 450 DEG C, and 600 DEG C for 10 minutes or less under an N2 atmosphere. In particular, the time-temperature cycle carried out is as follows: insert the article into the heating chamber at room temperature and at atmospheric pressure; The chamber is then heated to a test-critical temperature at a rate of 9 [deg.] C / min; The chamber was maintained at the test-limit temperature for 10 minutes; The chamber is then cooled to 200 DEG C at the furnace speed; Removing the article from the chamber and allowing it to cool to room temperature; And then rescanning the article with an optical scanner. The percent bubble area from the secondary scan was then calculated as above and the change in% bubble area (% bubble area) was determined by comparing the% bubble area from the primary scan. As noted above, a change in bubble area of &gt; 5% is significant and an indication of gas release. The change in% bubble area was originally chosen as the measurement criterion for variability in% bubble area. That is, most surface modification layers have a bubble area of about 2% in the primary scan due to handling and cleanliness after manufacturing thin sheets and carriers and before bonding them. However, a change may occur between the materials. The same substance # 1-6 described in connection with the primary gas release test method was used again in the secondary gas release test method. Of these materials, material # 1-4 exhibited a bubble area of about 2% in the primary scan while materials # 5 and # 6 showed a significantly larger bubble area in the primary scan, or about 4%.

The results of the secondary gas release test will be described with reference to Figures 11 and 12. [ The gas release test results for material # 1-3 are shown in Figure 11, while the gas release test results for material # 4-6 are shown in FIG.

The results for material # 1 are shown as square data points in FIG. As can be seen from the figure, the change in% bubble area was close to zero for the test-critical temperatures of 300 ° C, 450 ° C, and 600 ° C. Thus, substance # 1 does not exhibit gas evolution at this temperature.

The result for material # 2 is shown as a diamond data point in FIG. As can be seen from the figure, the change in% bubble area is less than 1 for the test-critical temperatures of 450 ° C and 600 ° C. Thus, substance # 2 does not exhibit gas evolution at this temperature.

The results for material # 3 are shown as triangular data points in FIG. As can be seen from the figure, similar to the results for material # 1, the change in% bubble area was close to zero for test-critical temperatures of 300 ° C, 450 ° C, and 600 ° C. Thus, substance # 1 does not exhibit gas evolution at this temperature.

The results for material # 4 are shown in Figure 12 as circular data points. As can be seen from the figure, the change in% bubble area is close to zero for the test-critical temperature of 300 ° C, but close to 1% for the test-critical temperature of 450 ° C and 600 ° C for some samples, And about 5% at the test-limit temperature of 450 [deg.] C and 600 [deg.] C for the other samples of the same material. The results for material # 4 are very inconsistent and depend on the manner in which the thin sheet and carrier surface are prepared for bonding with the HMDS material. The manner in which the sample runs depends on the manner in which the sample is made is consistent with the embodiments of such materials described in connection with Table 2 above, and the related discussion. It should be noted that for these materials, samples with a change in bubble area of close to 1% for 450 &lt; 0 &gt; C and 600 [deg.] C test-critical temperature did not allow separation of the thin sheet from the carrier according to the separation test described above Respectively. That is, strong adhesion between the thin sheet and the carrier may have limited bubble generation. On the other hand, a sample with a change in bubble area of close to 5% allowed separation of the thin sheet from the carrier. Thus, a sample that did not have gaseous emissions had undesirable consequences of increased adhesion (which prevented removal of the thin sheet from the carrier) after the temperature treatment to adhere the carrier and the thin sheet together, while allowing the removal of the thin sheet and carrier The sample had undesirable results of gas release.

The results for material # 5 are shown as triangular data points in FIG. As can be seen from the figure, the change in% bubble area is about 15% for the test-limit temperature of 300 ° C and well over that for the higher test-limit temperatures of 450 ° C and 600 ° C. Thus, substance # 5 exhibits significant gas evolution at this temperature.

The results for material # 6 are shown as square data points in FIG. As can be seen from this figure, the change in% bubble area exceeds 2.5% for the test-critical temperature of 300 ° C and exceeds 5% for the test-critical temperature of 450 ° C and 600 ° C. Thus, substance # 6 exhibits significant gas evolution at 450 ° C and test-critical temperatures of 600 ° C.

conclusion

It should be emphasized that the above-described embodiments of the invention, in particular any "preferred" embodiments, are merely possible embodiments of the described implementations for a clear understanding of the various principles of the invention. Many changes and modifications may be made to the above-described embodiments of the invention without departing from the spirit and various principles of the invention. All such changes and modifications are intended to be included within the scope of this disclosure and the present invention and protected by the following claims.

For example, many embodiments of the surface modification layer 30 are shown and discussed as being formed on the carrier 10, but may alternatively or additionally be formed on the thin sheet 20. That is, materials such as those described in Examples 4 and 3 can be applied to the carrier 10 to be bonded together, to the thin sheet 20, or to both the carrier 10 and the thin sheet 20.

It has also been described that some surface modification layers 30 control the bond strength so that the thin sheet 20 can be removed from the carrier 10 even after the article 2 is processed at a temperature of 400 캜 or 600 캜 The article 2 can of course be processed at a temperature lower than the temperature of the particular test through which the article has passed and the thin sheet 20 can still be removed from the carrier 10 without damaging the thin sheet 20 or the carrier 10. [ The same ability to remove can be achieved.

In addition, although the controlled coupling concept is described herein as being usable with carriers and thin sheets, in certain situations they can be applied to control the coupling between thicker sheets of glass, ceramic, or glass ceramic, Or a portion thereof) may be desorbed from each other.

Additionally, while the controlled bonding concept is described herein as useful with glass carriers and glass thin sheets, the carrier may be made of other materials, such as ceramics, glass ceramics, or metals. Similarly, a sheet that is controllably coupled to a carrier may be made of other materials, for example, ceramics or glass ceramics.

According to a first aspect,

Stacking a plurality of glass layers;

Exposing a stack of glass layers to a time-temperature cycle sufficient for each glass layer to compress,

Each of said glass layers has two major surfaces whereby an interface is defined between adjacent ones of the glass layers in the plurality of glass layers and a surface modification layer is formed on at least one of the major surfaces facing one of the interfaces, Respectively,

The surface modification layer is sufficient to control bonding between adjacent ones of the glass layers defining one of the interfaces in the stack during a time-temperature cycle, wherein the bonding is one layer is fixed and the other layer is gravity applied Is controlled to have a force such that one layer is not separated from another layer but the layers can be separated without destroying one of the adjoining ones of the glass layers into two or more pieces.

According to a second aspect, a method of aspect 1 is provided, wherein the time-temperature cycle comprises a temperature of &gt; = 400 [deg.] C but less than the strain point of the glass sheet.

According to a third aspect, the method of aspect 1 is provided, wherein the time-temperature cycle comprises a temperature of &gt; = 600 [deg.] C but less than the strain point of the glass sheet.

According to a fourth aspect, there is provided a method according to any of aspects 1 to 3, wherein the surface modification layer is one of HMDS, a plasma polymerized fluoropolymer and an aromatic silane.

According to a fifth aspect, when the surface modification layer comprises a plasma-polymerized fluoropolymer, the surface modification layer may comprise plasma-polymerized polytetrafluoroethylene; And a plasma-polymerized fluoropolymer surface modification layer deposited from a CF4-C4F8 mixture having &lt; 40% C4F8.

According to a sixth aspect, there is provided the method of aspect 4, wherein the surface modification layer is phenylsilane when the surface modification layer comprises an aromatic silane.

According to a seventh aspect, in the case where the surface modification layer comprises an aromatic silane, the surface modification layer is selected from the group consisting of phenyl triethoxysilane; Diphenyldiethoxysilane; And 4-pentafluorophenyltriethoxysilane. &Lt; / RTI &gt;

According to an eighth aspect, there is provided a method according to any one of aspects 1-7, wherein the time-temperature cycle is performed in an anoxic environment.

According to a ninth aspect, a method of any one of the aspects 1-8 is provided, wherein the stack of glass layers comprises a rolled glass sheet.

Claims (9)

Stacking a plurality of glass layers;
Exposing a stack of glass layers to a time-temperature cycle sufficient for each glass layer to compress,
Each of said glass layers has two major surfaces whereby an interface is defined between adjacent ones of the glass layers in the plurality of glass layers and a surface modification layer is formed on at least one of the major surfaces facing one of the interfaces, Respectively,
The surface modification layer is sufficient to control bonding between adjacent ones of the glass layers defining one of the interfaces in the stack during a time-temperature cycle, wherein the bonding is one layer is fixed and the other layer is gravity applied Is controlled to have a force such that one layer is not separated from another layer but the layers can be separated without destroying one of the adjacent ones of the glass layers into two or more pieces. 2. The method of claim 1 wherein the time-temperature cycle comprises a temperature of &gt; = 400 [deg.] C but less than the strain of the glass. 2. The method of claim 1 wherein the time-temperature cycle comprises a temperature of &gt; = 600 [deg.] C but less than the strain of the glass. 4. The method according to any one of claims 1 to 3, wherein the surface modification layer is one of HMDS, a plasma polymerized fluoropolymer and an aromatic silane. 5. The method of claim 4, wherein if the surface modification layer comprises a plasma polymerized fluoropolymer, the surface modification layer comprises plasma polymerized polytetrafluoroethylene; And a plasma-polymerized fluoropolymer surface modification layer deposited from a CF4-C4F8 mixture having &lt; 40% C4F8. 5. The method of claim 4, wherein if the surface modification layer comprises an aromatic silane, the surface modification layer is phenylsilane. 5. The method of claim 4, wherein if the surface modification layer comprises an aromatic silane, the surface modification layer is selected from the group consisting of phenyl triethoxysilane; Diphenyldiethoxysilane; And 4-pentafluorophenyltriethoxysilane. 8. The method of any one of claims 1 to 7, wherein the time-temperature cycle is performed in an anoxic environment. 9. The method according to any one of claims 1 to 8, wherein the stack of glass layers comprises a rolled glass sheet.

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