JP2017218338A - Glass substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass substrate capable of preventing damage, etc., due to a shock applied to the side surface from occurring.SOLUTION: A glass substrate 1 has a first surface 1a, a second surface 1b and a side surface 1c connecting the first surface 1a and the second surface 1b and can form a semiconductor element on the first surface 1a. The side surface 1c includes a damage prevention part 3 having a projection portion in which the edge of a cut surface is a curve when cut by a surface parallel to the first surface 1a constituted of a curved surface, and the damage prevention part 3 can be hemispherical and constituted of a wavy curved surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a glass substrate used for manufacturing a panel for a flat panel display, a semiconductor device chip and the like.

  A glass substrate having a property of transmitting light is widely used for a panel of a flat panel display (hereinafter, FPD). The panel generally used for FPD is produced using the glass substrate cut out from the larger glass substrate (it is called mother glass) than this panel. A semiconductor element for driving the FPD is provided on the glass substrate included in the panel, and the semiconductor element is formed on the mother glass before being cut into individual glass substrates.

  In order to reduce the manufacturing cost of FPD, it is effective to increase the number of glass substrates cut out from one mother glass. When the number of glass substrates cut out from the mother glass is increased, the number of glass substrates that can be processed in one step increases, so that the manufacturing cost of the panel can be reduced.

  In recent years, in order to increase the number of glass substrates that can be cut out from the mother glass, the mother glass has been increased in size, and a mother glass having a side exceeding 1 m has been put into practical use. In addition, with the increase in the size of the mother glass, the size of the FPD panel that can be produced is also increased, and an FPD exceeding 100 inches diagonal has been prototyped. For this reason, the demand for large glass substrates (mother glass) is increasing.

  By the way, a glass substrate is expected to serve as a substrate to replace a Si wafer as a substrate for next-generation semiconductor elements. In recent years, the trend toward large-sized Si wafers has been remarkable, and although development of processes for large-diameter Si wafers such as 450 mm has been actively developed, Si wafers with a size exceeding 1 m, which is realized with glass substrates, will be put into practical use. There are no signs.

  In view of this, research has been conducted on manufacturing a device chip by forming a semiconductor element on a glass substrate. When a semiconductor element is manufactured using a large glass substrate as a mother glass, a relatively large number of device chips can be manufactured from one mother glass, so that the cost per device chip can be reduced. In the first place, since the unit price per unit area of the glass substrate is lower than that of the Si wafer, it can be said that the use of the glass substrate is effective in reducing the cost of the device chip from this viewpoint.

  In the case where a device chip is manufactured using a glass substrate, a semiconductor layer or the like is formed on the glass substrate, and a semiconductor element using the semiconductor layer as an active layer is manufactured. Alternatively, a semiconductor element may be provided by transferring a semiconductor element previously formed on a Si wafer or the like onto a glass substrate. Patent Document 1 discloses an SOI (Silicon on Insulator) element provided on a glass substrate.

  However, a large glass substrate (mother glass) is heavy. Therefore, a large glass substrate is vulnerable to an unexpected impact applied during transportation. When an impact exceeding an allowable limit is applied to the glass substrate, damage such as cracks or chipping occurs, and the glass substrate cannot be used as a substrate for forming a semiconductor element. In general, a large glass substrate is more expensive than a small glass substrate, so that the damage when the glass substrate is damaged is large.

  Therefore, it has been studied to improve the strength of the glass substrate as a measure for preventing the occurrence of damage due to impact or the like. For example, Patent Document 2 discloses a glass substrate whose strength is increased by examining the composition and properties of the glass substrate.

JP 2010-87067 A International Publication No. 2008/7676

  However, the glass substrate on which the semiconductor element is provided needs to have a composition in which impurities or the like are not mixed into the semiconductor element from the glass substrate, and at the same time, distortion or the like does not occur due to heat applied in the process of forming the semiconductor element. Must be of nature. Therefore, when examining the composition so as to increase the strength of the glass substrate, it must be studied within a range that satisfies the characteristics required for the glass substrate on which the semiconductor element is formed, and therefore the range of the composition that can be examined is limited. .

  Moreover, the general shape of glass substrates, such as mother glass, is a substantially flat shape. That is, the glass substrate (mother glass) is flat on the front surface, the back surface, and the side surfaces. On the other hand, the general shape of a substrate such as a silicon wafer is generally disc-shaped, and the side surface is a curved surface. When an unexpected impact is applied to the side surface of the substrate, the impact is applied to the curved surface in the case of a silicon wafer, but in the case of a glass substrate such as mother glass, the impact is received on a flat surface.

  In general, when a surface subjected to impact is a flat surface, damage or the like is more likely to occur than a curved surface. Therefore, in the glass substrate, further countermeasures against damage must be studied on the side surface as compared with the silicon wafer.

  Moreover, in the flat glass substrate used for manufacture of the panel for FPD, a chamfering process may be given in order to prevent generation | occurrence | production of the crack of an edge part (especially corner | angular part), a crack, etc. However, even in the glass substrate subjected to the chamfering process, the corners connecting the first surface or the second surface and the side surfaces are removed, but regions other than the corners on the side surfaces are still present. Since no measures against impact are taken, it is vulnerable to impact.

  This invention is made | formed in view of this point, The place made into the objective is providing the glass substrate which is hard to produce a damage etc., even if an impact etc. are applied to a side surface.

  According to an aspect of the present invention, the semiconductor device includes a first surface, a second surface, and a side surface that connects the first surface and the second surface, and the semiconductor element is provided on the first surface. The side surface includes a breakage prevention portion, and the breakage prevention portion has a cut surface when the surface is formed by a curved surface and is cut by a plane parallel to the first surface. There is provided a glass substrate having a convex portion with a curved edge.

  Note that in the glass substrate according to one embodiment of the present invention, the breakage preventing portion may be hemispherical. In addition, the breakage prevention unit may be formed of a corrugated curved surface.

  The glass substrate which concerns on this invention is equipped with the damage prevention part on the side surface. Therefore, when an impact or the like is applied to the side surface of the glass substrate, the glass substrate receives an impact at the convex portion of the breakage preventing portion. Since the convex portion of the breakage preventing portion has a curved surface, the glass substrate receives the impact on the curved surface and is not easily damaged.

  Compared with the conventional chamfered portion, the breakage preventing portion has a higher degree of freedom in the arrangement interval, the number of arrangement, the height from the side surface of the glass substrate, the material and shape, the arrangement method, and the like. Therefore, the configuration of the breakage prevention unit can be determined as appropriate in accordance with the magnitude and type of the expected impact, and all types of impact can be handled.

  Therefore, the present invention provides a glass substrate that is less likely to be damaged even when an impact or the like is applied to the side surface.

FIG. 1A is a perspective view schematically showing a glass substrate in which a hemispherical damage prevention portion is disposed on a side surface, and FIG. 1B is a top view in which a corner of the glass substrate is enlarged. It is. FIG. 2A is a perspective view schematically showing a glass substrate in which a damage preventing portion having a corrugated curved surface is provided on the side surface, and FIG. 2B is an enlarged view of the corner of the glass substrate. FIG.

  Embodiments according to the present invention will be described with reference to the accompanying drawings. First, the glass substrate according to the present embodiment will be described. FIG. 1A is a perspective view schematically showing a glass substrate in which a hemispherical damage prevention portion is disposed on a side surface, and FIG. 1B is a top view in which a corner of the glass substrate is enlarged. It is. FIG. 2A is a perspective view schematically showing a glass substrate in which a damage preventing portion having a corrugated curved surface is provided on the side surface, and FIG. 2B is an enlarged view of the corner of the glass substrate. FIG. In addition, the number, shape, and arrangement of the breakage prevention portions are not limited to the drawings.

  The glass substrate 1 according to this embodiment has a substantially flat plate shape, and includes a first surface 1a, a second surface 1b, and a side surface 1c that connects the first surface 1a and the second surface 1b. A semiconductor element or the like can be provided on the first surface 1a or the second surface 1b. A film or the like constituting the semiconductor element is laminated on the surface on which the semiconductor element is disposed. However, if the film formation surface has irregularities, the irregularities are reflected in the various films to be laminated. Cause variations in the characteristics of the semiconductor elements.

  Therefore, the surface of the glass substrate on which the semiconductor element is formed must be sufficiently flat. And the thinner the film constituting the semiconductor element, the more easily the semiconductor element is affected by the unevenness of the surface to be formed. However, in recent years, the trend of downsizing and thinning of the semiconductor element formed on the glass substrate is remarkable. Further flatness is demanded on the surface of.

  For example, the thinnest film among the films constituting the semiconductor element may have a thickness of 20 nm or less. In order to prevent the thin film from being affected by the unevenness of the surface to be formed, for example, the first surface 1a or the second surface 1b of the glass substrate has an average surface roughness (Ra) of 10 nm. It is preferable that it is below, especially 5 nm or less. Moreover, it is preferable that the surface roughness (Ra) is less than or equal to 1/2 of the thinnest film among the respective films constituting the semiconductor element to be formed, and particularly preferably less than or equal to 1/4.

  If the glass substrate 1 contains an alkali metal element (such as sodium or potassium), the alkali metal element moves to the semiconductor element disposed on the glass substrate 1 and affects the electrical characteristics of the semiconductor element. There is a case. Therefore, it is preferable to provide a barrier film between the glass substrate 1 and the semiconductor element in order to prevent the movement of the alkali metal element, or to use a non-alkali glass with a small content of the alkali metal element for the glass substrate.

  Next, the damage prevention part 3 with which the side surface 1c of the glass substrate 1 which concerns on this embodiment is provided is demonstrated. The breakage preventing portion 3 has a convex portion, and the edge of the cut surface when the convex portion is cut in a plane parallel to the first surface 1a of the glass substrate 1 becomes a curve. In other words, when the breakage preventing portion 3 is observed from a direction perpendicular to the first surface 1a or the second surface 1b, it has a curved shape. Since the damage prevention portion is provided on the side surface 1c of the glass substrate 1, when the impact or the like is applied to the side surface 1c of the glass substrate 1, the glass substrate 1 receives the impact on the damage prevention portion 3.

  In the case of a general glass substrate having a flat side surface, when the side surface receives an impact, the glass substrate receives an impact on the plane. If the surface subjected to impact is a flat surface, the glass substrate is likely to be damaged such as chipping or cracking. On the other hand, as in the case of the glass substrate 1 according to the present embodiment, when the damage prevention portion 3 is provided on the side surface and the convex portion of the breakage prevention portion 3 has the above-described shape, the impact is received on the curved surface and is damaged. Is unlikely to occur.

  Next, the shape of the breakage preventing portion 3 will be described in detail. An example of the shape of the breakage preventing portion 3 is a shape that is hemispherical and has a convex portion 3a as shown in FIGS. 1 (A) and 1 (B). The hemispherical shape is not limited to a shape cut by a plane passing through the center of the sphere, and may be a shape cut by a plane not including the center. Moreover, not only the shape which cut | disconnected the ball | bowl but the shape which cut | disconnected the ellipsoid may be sufficient.

  For example, when a shape obtained by cutting a sphere is adopted for the breakage preventing portion 3, the radius of curvature may be 1 mm or less, preferably 0.5 mm or less. However, the size of the breakage prevention portion 3 is larger than the thickness of the glass substrate 1, and the breakage prevention portion 3 is arranged in the thickness direction of the glass substrate 1 when the breakage prevention portion 3 is disposed on the side surface of the glass substrate 1. When protruding, the protruding portion may be removed.

  The radius of curvature of the breakage preventing portion 3 is determined to be 0.5 times or less, preferably 0.25 times or less the thickness of the glass substrate 1 so that the breakage preventing portion 3 does not protrude in the thickness direction of the glass substrate 1. May be. However, the breakage prevention unit according to the present embodiment is not necessarily limited to this.

  Moreover, in order to disperse the impact received by the breakage prevention unit 3, a plurality of breakage prevention units 3 may be disposed on the side surface 1 c of the glass substrate 1. The larger the number of breakage prevention portions 3 provided, the more the impact can be dispersed. Furthermore, since the one where the distance between the some damage prevention parts 3 arrange | positioned is small can arrange | position the damage prevention part 3 densely, it is preferable.

  For example, when a plurality of hemispherical breakage prevention portions 3 are disposed on the side surface 1c of the glass substrate 1, the distance between two adjacent breakage prevention portions 3 (the end portion of one breakage prevention portion 3 and the other end) The distance from the end of the breakage prevention unit 3 may be in the range of 1 mm to 5 mm. More preferably, the range is 1 mm to 2 mm. Further, the distance may be determined in the range of 1 to 5 times the radius of curvature of the breakage preventing portion 3, more preferably in the range of 1 to 2 times. However, the breakage prevention unit according to the present embodiment is not necessarily limited to this.

  In addition, when making the breakage prevention part 3 hemispherical, it is not necessary to unify all the curvature radii of the plurality of breakage prevention parts 3, and a plurality of types of breakage prevention parts 3 having different curvature radii are arranged on the side surface 1 c of the glass substrate 1. May be mixed. Moreover, it is not necessary to unify the distance between the breakage prevention portions 3 over the entire side surface, and in the side surface 1c of the glass substrate 1, a region with a large interval between the breakage prevention portions 3 and a region with a small interval may be mixed. .

  The portion of the side surface 1c of the glass substrate 1 that is expected to receive a large impact may be provided with the damage prevention portion 3 in close proximity to protect it intensively, and the portion that is unlikely to receive a large impact is damaged. The prevention unit 3 may be provided sparsely.

  Another example of the shape of the breakage preventing portion 3 is a shape constituted by a corrugated curved surface as shown in FIGS. 2 (A) and 2 (B). The breakage preventing portion 3 formed of a corrugated curved surface has a convex portion 3a. Moreover, as for the convex part 3a which the breakage prevention part 3 has, the edge of a cut surface when it cut | disconnects in a surface parallel to the 1st surface 1a of the glass substrate 1 becomes a curve. Further, as shown in FIGS. 2A and 2B, the convex portion 3a is sandwiched between adjacent concave portions 3b.

  Note that the breakage prevention unit 3 formed of a corrugated curved surface may have, for example, a corrugated wave height (the amplitude of the corrugation) of about 1 mm. Further, the distance (hereinafter referred to as wavelength) from the corrugated recess 3b to the adjacent recess 3b through the projection 3a may be determined in the range of 1 mm to 5 mm. More preferably, the range is 1 mm to 2 mm. The wavelength is determined in the range of 1 to 5 times the wave height, more preferably in the range of 1 to 2 times. However, the breakage prevention unit 3 according to the present embodiment is not necessarily limited to this.

  Further, when the breakage prevention part 3 has a shape composed of a corrugated curved surface, when one breakage prevention part 3 is formed from the recess 3b to the adjacent recess 3b through the projection 3a, a plurality of breakage preventions are provided. The part 3 may be disposed on the side surface 1 c of the glass substrate 1. When a plurality of the breakage prevention portions 3 are arranged on the side surface 1c, as shown in FIG. 2A, even if the plurality of breakage prevention portions 3 form a corrugated curved surface that extends over the entire side surface 1c. Good.

  In addition, the plurality of breakage prevention units 3 formed of corrugated curved surfaces may not all have the same wavelength and wave height, and a plurality of breakage prevention units 3 having different wavelengths and wave heights may be mixed. For example, the portion of the side surface 1c of the glass substrate 1 that is highly likely to receive a large impact may be protected intensively by reducing the wavelength of the corrugated wave and making the convex portions 3a dense, and the possibility is low. The convex portions 3a may be provided sparsely in the portion. In addition, between the some damage prevention parts 3, you may have the shape (for example, straight line) different from a corrugation in the side surface 1c of the glass substrate 1. FIG.

  Further, the breakage preventing portion 3 formed of a corrugated curved surface has a shape in which a corner portion connected to the first surface 1a of the glass substrate 1 and a corner portion connected to the second surface 1b are chamfered. It may be.

  The breakage prevention portions 3 in the glass substrate 1 according to the present embodiment are high in the number of the breakage prevention portions 3 to be arranged, the arrangement interval, the height from the side surface 1c of the glass substrate 1, the material and shape, the arrangement method, and the like. Has freedom. Therefore, the configuration of the breakage prevention unit 3 can be determined as appropriate in accordance with the expected magnitude and type of impact, and can cope with all types of impact.

  Next, a method for disposing the breakage preventing portion 3 on the side surface 1c of the glass substrate 1 will be described. The breakage preventing portion 3 can be formed, for example, by partially removing the side surface 1c of the glass substrate 1 having a flat side surface 1c. In that case, the breakage preventing portion 3 can be formed using a cutting device or a laser processing device. Note that when the breakage prevention part 3 is formed by removing a part of the glass substrate 1, the breakage prevention part 3 is made of the same material as the glass substrate 1, so the boundary between the two is not necessarily clear.

  Moreover, the breakage prevention part 3 can also be formed in the manufacturing process of the mother glass. As a method for producing a mother glass, a fusion method, a float method, or the like is known. As a feature common to each method, there is a step of heating glass as a material to change it into molten glass. Then, the molten glass is shaped into a plate shape, slowly cooled and cured, and cut into a predetermined length to form a flat glass substrate (mother glass). Therefore, the breakage preventing portion 3 is formed on the side surface of the glass substrate (mother glass) after the molten glass is shaped into a plate shape and then slowly cooled and cured.

  In this case, for example, a mold having a shape to be transferred and serving as the breakage prevention unit 3 is prepared, and the mold is directed toward the side of the glass after the molten glass is shaped into a flat plate and slowly cooled. Push in moderately. Then, the shape of the mold is transferred to the side surface pushed by the mold. Then, when the glass is gradually cooled to be cured and cut into a predetermined length, a glass substrate (mother glass) having a damage prevention portion 3 disposed on the side surface is obtained.

  Furthermore, when the glass is cut into a predetermined length to form a glass substrate (mother glass), the breakage preventing portion 3 can be formed on the cut surface by cutting into a corrugated shape, for example.

  Further, the breakage prevention unit 3 may be formed by arranging a member prepared separately from the glass substrate 1 on the side surface 1 c of the glass substrate 1. For example, a plurality of members such as a hemispherical shape, a spherical shape, or a columnar shape are prepared. Then, an adhesive member is disposed on the side surface 1c of the glass substrate 1 or the surface of the member. Next, the breakage preventing portion 3 is formed by bonding a member that forms the breakage preventing portion 3 to the side surface 1c of the glass substrate 1 through the adhesive member.

  Thus, when the member which forms the breakage prevention part 3 is prepared separately from the glass substrate 1 and bonded to the side surface 1c of the glass substrate 1 via the adhesive member, the breakage prevention part 3 is made of a material other than glass. Can be adopted. For example, resin materials such as polyimide, acrylic, and urethane may be used, and inorganic materials such as silicon dioxide, silicon nitride, and aluminum may be used. The material used for the breakage prevention unit 3 can be appropriately selected according to the type and degree of impact applied to the side surface 1c of the glass substrate 1.

  However, when a semiconductor element is formed on the glass substrate 1 after disposing the breakage prevention part 3 on the side surface 1c of the glass substrate 1, the material constituting the breakage prevention part 3 is heat applied in the process of forming the semiconductor element. Must be a material that can withstand

  Further, in the case where the breakage prevention portion 3 composed of a corrugated curved surface is disposed on the side surface of the glass substrate 1 cut out from the mother glass, the breakage prevention portion 3 can be formed simultaneously with the division of the mother glass. For example, when the mother glass is cut using a laser processing apparatus, the same wave-shaped dividing groove as the outer shape of the breakage preventing portion 3 to be formed is formed in the mother glass. When the mother glass is divided with the dividing groove as a boundary, the edge of the glass substrate 1 constituting the dividing groove becomes corrugated, and the corrugated breakage preventing portion 3 is formed on the side surface 1 c of the glass substrate 1.

  By the above, the glass substrate 1 provided with the damage prevention part 3 on the side surface 1c can be produced. The breakage preventing portion 3 is formed of a curved surface, and has a convex portion whose edge of the cut surface becomes a curve when cut along a plane parallel to the first surface 1a. That is, since the curved surface is provided on the side surface 1c of the glass substrate 1, the glass substrate 1 is hardly damaged.

  In addition, this invention is not limited to description of the said embodiment, A various change can be implemented. For example, in the above embodiment, the glass substrate 1 in which the breakage preventing portion 3 is formed on the side surface 1c has been described. However, for example, when the glass substrate 1 having the breakage prevention unit 3 is carried to a semiconductor element manufacturing apparatus, or after a semiconductor element is formed on the glass substrate 1, a part of the breakage prevention unit 3 or All may be removed from the side surface 1 c of the glass substrate 1.

  When the possibility of breakage due to impact on the side surface is reduced, the FPD panel or device chip may be easily formed by removing the breakage prevention portion 3. On the other hand, the glass substrate 1 may be used for the panel for FPD and a device chip in the state by which the damage prevention part 3 was arrange | positioned on the side surface.

  In addition, the structure, method, and the like according to the above-described embodiment can be appropriately modified and implemented without departing from the scope of the object of the present invention.

DESCRIPTION OF SYMBOLS 1 Glass substrate 1a 1st surface 1b 2nd surface 1c Side surface 3 Damage prevention part 3a Convex part 3b Concave part

Claims (3)

A glass substrate comprising: a first surface; a second surface; and a side surface connecting the first surface and the second surface, wherein a semiconductor element can be formed on the first surface. There,
The side surface includes a breakage prevention portion,
The glass substrate characterized in that the breakage prevention part has a convex part which is formed of a curved surface and the edge of the cut surface becomes a curve when cut along a plane parallel to the first surface.   The glass substrate according to claim 1, wherein the breakage preventing portion is hemispherical.   The glass substrate according to claim 1, wherein the breakage preventing portion is constituted by a corrugated curved surface.