JP2013144613A - Method for manufacturing glass substrate used for forming through-electrode of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a glass substrate used for forming the through-electrode of a semiconductor device, which can appropriately form a plurality of through holes without producing cracks or deformations, etc., in the glass substrate, by irradiating the glass substrate with laser light.SOLUTION: The method for manufacturing a glass substrate used for forming the through-electrode of a semiconductor device has: (1) a step for preparing a glass substrate having a thickness of 0.01-5 mm, an included amount of SiOof 50-70 wt.%, and an average thermal expansion coefficient of 10×10K-50 to 10/K; (2) a step for arranging the glass substrate on the optical path of excimer laser light that is output from an excimer laser light generator; (3) a step for arranging a mask which does not have through holes, on the optical path between the excimer laser light generator and the glass substrate; and (4) a step for emitting the excimer laser light from the excimer laser light generator onto the glass substrate along the optical path.

Description

  The present invention relates to a method for producing a glass substrate for forming a semiconductor device through electrode.

  In order to meet the demand for higher density of printed circuit boards accompanying higher density mounting, multilayer printed circuit boards in which a plurality of printed circuit boards are stacked have been developed. In such a multilayer circuit board, a fine through-hole having a diameter of about 100 μm or less called a via hole is formed in a resin insulating layer, and plating is performed on the inside thereof, and a conductive layer between printed circuit boards stacked vertically. Connect each other electrically.

  As a method of forming such a through hole more easily, Patent Documents 1 and 2 describe a method of irradiating the insulating layer with laser light through a mask in which a large number of through holes are formed. According to this method, since a plurality of through holes can be simultaneously formed in the resin insulating layer, it is considered that a large number of through holes (via holes) can be formed more easily.

  Further, in order to meet the demand for smaller and thinner IC chips, in recent years, wafer level package (WLP) technology has been actively used. This is a technology that enables the package size to be reduced to the same size as an IC chip. On the surface of the wafer on which the IC is formed, rewiring, solder bump processing, resin sealing, etc. necessary for a semiconductor package are performed, followed by dicing. Each chip is separated into individual pieces by processing. In the WLP technology, a silicon wafer sealed with resin is usually separated into pieces by dicing, but recently, from the viewpoint of reliability, glass bonded to silicon by anodic bonding technology or the like has been used. It has become.

  In addition, with increasing demands for smaller, faster, and lower power consumption of semiconductor devices, a combination of system-in-package (SiP) technology and three-dimensional mounting technology, which accommodates multiple LSI systems in one package Development of three-dimensional SiP technology is also underway. In this case, since the wire bonding technology cannot cope with a fine pitch, a relay substrate called an interposer using through electrodes is required.

JP 2005-88045 A JP 2002-126886 A

  The resin insulating layer as described above is affected by warpage, deformation, etc., so that the positioning accuracy is deteriorated and is not suitable for high-density mounting. Therefore, it is desired to apply a material that can replace the resin insulating layer to the substrate material.

  For example, the use of silicon as an interposer material having through electrodes has been studied. This is because silicon can be processed with fine holes relatively easily by dry etching. However, since silicon is a semiconductor, it is necessary to insulate the inner wall of the through hole in order to ensure insulation. Further, such an insulation process is expected to become more difficult as the size of the through-hole is reduced in the future.

  Therefore, it is desired to use an insulating glass substrate instead of the resin insulating layer. For example, if a plurality of fine through holes can be formed in a glass substrate, such a glass substrate can be applied as an interposer.

  However, even if the glass substrate is irradiated with laser light under the same conditions as in the case where through holes are formed in a resin insulating layer, it is extremely difficult to properly form a large number of fine through holes in the glass substrate. There is a case. Glass may be inferior in workability compared to resin. Further, since glass is a brittle material, it is difficult to form fine through-holes without causing cracks or deformation in the glass substrate unless laser processing is performed under appropriate conditions.

  On the other hand, if a wet etching technique or a dry etching technique is used, it is possible to simultaneously form a plurality of through holes in a glass substrate. However, in this case, the process becomes complicated, the processing time becomes long, and problems such as waste liquid processing may occur.

  The present invention has been made in view of the above problems. In the present invention, by irradiating a glass substrate with laser light, a plurality of through-holes can be formed without causing cracks or deformation in the glass substrate. It aims at providing the manufacturing method of the glass substrate for semiconductor device penetration electrode formation which can be formed appropriately.

In the present invention, a method for producing a glass substrate for forming a semiconductor device through electrode,
(1) thickness of 0.01 mm to 5 mm, SiO ₂ content of a glass substrate of 50 wt% to 70 wt%, average thermal expansion coefficient of ^{10 × 10 -7 / K~50 × 10} -7 / K Prepare a glass substrate
(2) The glass substrate is disposed on an optical path of excimer laser light from an excimer laser light generator,
(3) A mask having no through-opening is disposed on the optical path between the excimer laser light generator and the glass substrate,
(4) A manufacturing method is provided in which a through-hole is formed in the glass substrate by irradiating the glass substrate with the excimer laser light along the optical path from the excimer laser light generator.

  Here, in the manufacturing method according to the present invention, the mask having no through-opening may be configured by providing a pattern of a reflective layer on a surface of a substrate transparent to the excimer laser light.

  In the manufacturing method according to the present invention, the reflective layer may be made of at least one metal selected from Cr (chromium), Ag (silver), Al (aluminum), and Au (gold). You may comprise by installing in.

  In the manufacturing method according to the present invention, the pattern of the reflective layer may include a portion where the reflective layer is provided and a portion where the substantially circular reflective layer is not provided.

In the method according to the invention, the step of irradiating the excimer laser beam, the excimer laser beam irradiation fluence is 2~20J / cm ^2, the irradiation fluence (J / cm ²⁾ and the number of shots (times ) And the thickness (mm) of the glass substrate may include a step of irradiating so that the product is 1000 to 30000.

  In the manufacturing method according to the present invention, a tapered through hole having a taper angle of 0.1 ° to 20 ° may be formed in the glass substrate by the step of irradiating the excimer laser beam.

In the manufacturing method according to the present invention, the excimer laser light may be any one of a KrF laser, an ArF laser, and an F ₂ laser.

  In the present invention, a glass for forming a semiconductor device through electrode that can appropriately form a plurality of through holes without causing cracks or deformation in the glass substrate by irradiating the glass substrate with laser light. A method for manufacturing a substrate can be provided.

It is an expanded sectional view of the through hole in the glass substrate of the present invention. It is the figure which showed roughly one structure of the manufacturing apparatus used for the manufacturing method of this invention. It is the figure which showed roughly the flow of the manufacturing method of this invention. It is the top view which showed roughly the mask used in the Example.

  The present invention will be described below with reference to the drawings.

(About the glass substrate obtained by the manufacturing method by this invention)
First, the glass substrate obtained by the manufacturing method of the glass substrate for semiconductor device penetration electrode formation in this invention is demonstrated.

A glass substrate for forming a semiconductor device through electrode obtained by the production method of the present invention (hereinafter, also simply referred to as “glass substrate of the present invention”) has a thickness of 0.01 mm or more and 5 mm or less, and is 50 ° C. to 300 ° C. The average thermal expansion coefficient (hereinafter, also simply referred to as “thermal expansion coefficient”) is 10 × 10 ⁻⁷ / K or more and 50 × 10 ⁻⁷ / K or less. Further, the glass substrate of the present invention, SiO ₂ content is in the range of 50 wt% to 70 wt%.

  It is considered that a normal glass substrate may not be used as an insulating layer of a multilayer circuit board as described above, a glass for WLP, or an interposer depending on its properties. When a glass insulating layer is laminated on a silicon wafer and the silicon wafer and the glass insulating layer are bonded, the insulating layer or WLP glass may be peeled off from the silicon wafer or the wafer may be warped. Because it is done. Further, when glass is used as an interposer, there is a risk of warping of parts due to a difference in thermal expansion between the chip made of silicon and the glass interposer.

  On the other hand, the glass substrate of this invention has a thermal expansion coefficient in the above-mentioned range. Therefore, even if the glass substrate of the present invention is laminated on a silicon wafer, or conversely, a chip composed of silicon is laminated on the top, peeling between the glass substrate and the silicon wafer may occur. It is difficult for the silicon wafer to be deformed.

In particular, the thermal expansion coefficient of the glass substrate is preferably 25 × 10 ⁻⁷ / K or more and 45 × 10 ⁻⁷ / K or less, and is 30 × 10 ⁻⁷ / K or more and 40 × 10 ⁻⁷ / K or less. It is more preferable. In this case, peeling and / or deformation is further suppressed. In addition, when it is necessary to obtain matching with a resin substrate such as a mother board, it is preferable that the thermal expansion coefficient of the glass substrate is 35 × 10 ⁻⁷ / K or more.

  In the present invention, the average coefficient of thermal expansion from 50 ° C. to 300 ° C. means a value obtained by measuring using a differential thermal dilatometer (TMA) and based on JIS R3102 (1995).

  The glass substrate of the present invention has a thickness of 0.01 mm to 5 mm. This is because when the thickness of the glass substrate is greater than 5 mm, it takes time to form the through-hole, and when it is less than 0.01 mm, problems such as cracking occur. The thickness of the glass substrate of the present invention is more preferably 0.02 to 3 mm, and further preferably 0.02 to 1 mm. The thickness of the glass substrate is particularly preferably from 0.05 mm to 0.4 mm.

The glass substrate of the present invention has a SiO ₂ content of 50 wt% or more and 70 wt% or less. If the SiO ₂ content is higher than this, cracks are likely to occur on the back surface of the glass substrate during the formation of the through holes. More preferably, the SiO ₂ content is 55 wt% or more and 62 wt% or less.

It is known that the cracking behavior of glass differs between glass with high SiO ₂ content and glass with low SiO ₂ content. Glass with extremely high SiO ₂ content generates cone-shaped cracks due to contact with objects. It becomes easy. On the other hand, a glass having an extremely low SiO ₂ content is likely to be cracked due to contact with an object. Therefore, it is possible to make it difficult to generate cracks and cracks by controlling the SiO ₂ content in the glass substrate.

The glass substrate of the present invention preferably has a low alkali content. Specifically, the total content of sodium (Na) and potassium (K) is preferably 3.5% by mass or less in terms of oxide. When total content exceeds 3.5 mass%, possibility that a thermal expansion coefficient will exceed 50 * 10 < ^-7 > / K will become high. The total content of sodium (Na) and potassium (K) is more preferably 3% by mass or less. When the glass substrate of the present invention is used for a high-frequency device, or when a large number of through holes are formed at a very fine pitch, such as when a large number of through holes of 50 μm or less are formed at a pitch of 200 μm or less, the glass substrate is Particularly preferred is alkali-free glass.

  Here, the alkali-free glass means a glass in which the total amount of alkali metals is less than 0.1% by mass in terms of oxide.

  The glass substrate of the present invention preferably has a dielectric constant of 6 or less at 25 ° C. and 1 MHz. Further, the glass substrate of the present invention preferably has a dielectric loss of 0.005 or less at 25 ° C. and 1 MHz. By reducing the dielectric constant and dielectric loss, excellent device characteristics can be exhibited.

Specific examples of the glass substrate include AN100 glass (manufactured by Asahi Glass), EAGLE glass (manufactured by Corning), and SW glass (manufactured by Asahi Glass). The thermal expansion coefficient of these glass substrates is 10 × 10 ⁻⁷ / K or more and 50 × 10 ⁻⁷ / K or less.

The characteristic of AN100 glass is that it is a non-alkali glass having a thermal expansion coefficient of 38 × 10 ⁻⁷ / K, and the total content of Na ₂ O and K ₂ O is less than 0.1 wt%. The AN100 glass has a Fe content of 0.05 wt%.

SW glass has a thermal expansion coefficient of 36 × 10 ⁻⁷ / K, the total content of Na ₂ O and K ₂ O is 3 wt%, and the content of Fe is 50 mass ppm.

  The glass substrate of the present invention has a plurality of through holes. Each through hole may be circular. In this case, the diameter of the through hole varies depending on the use of the glass substrate of the present invention, but generally it is preferably in the range of 5 μm to 500 μm. When the glass substrate of the present invention is used as the insulating layer of the multilayer circuit board as described above, the diameter of the through hole is more preferably 0.01 mm to 0.2 mm, and 0.02 mm. More preferably, it is -0.1 mm. In addition, by applying the wafer level package (WLP) technology, the glass substrate of the present invention can be laminated on the wafer to form an IC chip used for a pressure sensor or the like. The diameter of the hole is more preferably 0.1 to 0.5 mm, and further preferably 0.2 to 0.4 mm. Further, in this case, the diameter of the through hole for taking out the electrode different from the air hole is more preferably 0.01 to 0.2 mm, and further preferably 0.02 to 0.1 mm. In particular, when used as a through electrode such as an interposer, the diameter of the through hole is more preferably 0.005 to 0.075 mm, and further preferably 0.01 to 0.05 mm.

  As will be described later, in the glass substrate of the present invention, the diameter of the circular through hole at one opening surface may be different from the diameter at the other opening surface. In this case, the “diameter of the through hole” means the larger diameter of the two opening surfaces.

  The ratio (ds / dl) between the larger diameter (dl) and the smaller diameter (ds) is preferably 0.2 to 0.99, more preferably 0.5 to 0.90. preferable.

In the glass substrate of the present invention, the number density of the through holes varies depending on the use of the glass substrate of the present invention, but is generally in the range of 0.1 / mm ^{2 to} 10,000 / mm ² . When the glass substrate of the present invention is used as an insulating layer of a multilayer circuit board as described above, the number density of the through holes is preferably in the range of 3 / mm ^{2 to} 10000 / mm ² , 25 More preferably, it is in the range of pieces / mm ^{2 to} 100 pieces / mm ² . In addition, when the wafer level package (WLP) technology is applied and the glass substrate of the present invention is stacked on the wafer to form an IC chip used for a pressure sensor or the like, the number density of the through holes is 1 piece / mm ^2. It is preferably ˜25 pieces / mm ² , and more preferably 2 pieces / mm ² to 10 pieces / mm ² . When used as a through electrode such as an interposer, the number density of through holes is more preferably 0.1 piece / mm ^{2 to} 1000 piece / mm ² , and 0.5 piece / mm ^{2 to} 500 piece / mm. ² is more preferable.

  In the glass substrate of the present invention, the cross-sectional area of the through hole may monotonously decrease from one opening toward the other opening. This feature will be described with reference to FIG.

  In FIG. 1, an example of the expanded sectional view of the through-hole formed in the glass substrate of this invention is shown.

  As shown in FIG. 1, the glass substrate 1 of the present invention has a first surface 1a and a second surface 1b. Further, the glass substrate 1 has a through hole 5. The through hole 5 penetrates from the first opening 8a provided on the first surface 1a of the glass substrate 1 to the second opening 8b provided on the second surface 1b.

  The diameter of the through hole 5 at the first opening 8a is L1, and the diameter at the second opening 8b is L2.

  The through hole 5 has a “taper angle” α. Here, the taper angle α means an angle formed by the normal line (dotted line in the figure) of the first surface 1a (and the second surface 1b) of the glass substrate 1 and the wall surface 7 of the through hole 5.

  In FIG. 1, the angle formed between the normal line of the glass substrate 1 and the right wall surface 7a of the through hole 5 is α, but in FIG. 1, the normal line of the glass substrate 1 and the left surface 7b of the through hole are formed. Similarly, the angle formed by and is the taper angle α. Normally, the right taper angle α and the left taper angle α have substantially the same value. The difference between the taper angle α on the right side and the taper angle α on the left side may be about 30%.

  In the glass substrate of the present invention, the taper angle α is preferably in the range of 0.1 ° to 20 °. When the through hole of the glass substrate has such a taper angle α, when applying the wire bonding method, the wire is quickly inserted from the first surface 1a side of the glass substrate 1 to the inside of the through hole 5. It becomes possible to do. This also makes it possible to more easily and reliably connect the conductive layers of the printed circuit boards stacked on the top and bottom of the glass substrate through the through holes of the glass substrate. The taper angle α is particularly preferably in the range of 0.5 ° to 10 °.

  As will be described later, in the method for manufacturing a glass substrate according to the present invention, the taper angle α can be arbitrarily adjusted.

In the present application, the taper angle α of the through hole 5 of the glass substrate 1 can be obtained as follows:
Obtaining the diameter L1 of the through-hole 5 in the opening 8a on the first surface 1a side of the glass substrate 1;
Obtaining the diameter L2 of the through-hole 5 in the opening 8b on the second surface 1b side of the glass substrate 1;
Find the thickness of the glass substrate 1;
Assuming that the taper angle α is uniform in the entire through hole 5, the taper angle α is calculated from the measured value.

The glass substrate of the present invention preferably has an absorption coefficient with respect to the wavelength of excimer laser light of 3 cm ⁻¹ or more. In this case, formation of the through hole becomes easier. In order to absorb excimer laser light more effectively, the content of iron (Fe) in the glass substrate is preferably 20 mass ppm or more, more preferably 0.01 mass% or more, The content is more preferably 0.03% by mass or more, and particularly preferably 0.05% by mass or more. On the other hand, when there is much Fe content, coloring will become strong and there exists a problem that the alignment at the time of laser processing becomes difficult. The Fe content is preferably 0.2% by mass or less, and more preferably 0.1% by mass or less.

  The glass substrate of the present invention is preferably used for applications such as semiconductor device members, more specifically, insulating layers of multilayer circuit boards, wafer level packages, through holes for electrode extraction, interposers and the like.

(About the manufacturing method of the glass substrate by this invention)
Next, the manufacturing method of the glass substrate of the present invention having the above-described features will be described.

  In general, it is difficult to form a sound through hole even if a glass plate is simply irradiated with laser light. If the irradiation fluence (energy density) of the laser beam is increased, it may be possible to form a through hole. However, since glass is a brittle material, in this case, cracks and deformation usually occur in the glass. . Further, when the irradiation fluence of the laser beam is weakened, the through hole cannot be formed, and a crack may occur depending on the type of the laser beam and the properties of the sheet glass.

  The inventor of the present application has made extensive studies and found that a glass substrate having a through-hole can be formed without causing cracks in the glass substrate depending on the combination of the specific laser beam and the specific glass substrate. Was completed.

That is, in the present invention, excimer laser light is selected as the laser light, the glass substrate has a thickness of 0.01 mm to 5 mm, and an average thermal expansion coefficient at 50 ° C. to 300 ° C. is 10 × 10 ⁻⁷ / K. It is in the range of ˜50 × 10 ⁻⁷ / K and the SiO ₂ content is 50 wt% to 70 wt%. Thereby, a some fine through-hole can be appropriately formed in a glass substrate.

  Moreover, this inventor discovered the suitable irradiation fluence conditions at the time of forming the glass substrate which has a through-hole. That is, if the product of the irradiation fluence, the number of shots, and the thickness of the plate-like glass substrate is within a certain range and the glass substrate is irradiated with excimer laser light, a more appropriate through hole can be formed. Furthermore, a through-hole having a desired taper angle can be formed by adjusting the irradiation fluence.

  Hereinafter, with reference to FIG. 2 and FIG. 3, the manufacturing method of the glass substrate of this invention is demonstrated in detail.

  In FIG. 2, an example of the manufacturing apparatus block diagram used when manufacturing the glass substrate of this invention is shown.

  As shown in FIG. 2, the manufacturing apparatus 100 includes an excimer laser light generator 110, a mask 130, and a stage 140. A plurality of mirrors 150 to 151 and a homogenizer 160 are disposed between the excimer laser light generator 110 and the mask 130. Further, another mirror 152 and a projection lens 170 are disposed between the mask 130 and the stage 140.

  The mask 130 does not have a through opening, but has a configuration in which a pattern of a reflective layer is disposed on a base material (transparent base material) that is transparent to laser light. Therefore, in the mask 130, the portion where the reflective layer is installed on the transparent substrate can block the laser beam, and the portion where the reflective layer is not installed can transmit the laser beam.

  On the stage 140, a glass substrate 120 to be processed is disposed. The glass substrate 120 can be moved to an arbitrary position by moving the stage 140 two-dimensionally or three-dimensionally.

  In such a configuration of the manufacturing apparatus 100, the excimer laser light 190 generated from the excimer laser light generator 110 passes through the first mirror 150, the homogenizer 160, and the second mirror 151 and is incident on the mask 130. The excimer laser beam 190 is adjusted to a laser beam with uniform intensity when it passes through the homogenizer 160.

  As described above, the mask 130 has a reflective layer pattern on a substrate transparent to the laser light. For this reason, the excimer laser beam 190 is emitted from the mask 130 in a pattern corresponding to the pattern of the reflective layer (more specifically, the portion where the reflective layer is not provided).

  Thereafter, the direction of the laser light 190 transmitted through the mask 130 is adjusted by the third mirror 152, reduced and projected by the projection lens 170, and is incident on the glass substrate 120 indicated on the stage 140. A plurality of through holes are simultaneously formed in the glass substrate 120 by the laser light 190.

  After the through hole is formed in the glass substrate 120, the glass substrate 120 may be moved on the stage 140 and then the excimer laser light 190 may be irradiated again on the glass substrate 120. Thereby, a desired through hole can be formed in a desired portion of the surface of the glass substrate 120. That is, in this method, a known step-and-repeat method can be applied.

  In addition, it is preferable that the projection lens 170 can irradiate the entire processing region on the surface of the glass substrate 120 with the excimer laser light 190 to form a through hole at a time. However, it is usually difficult to obtain an irradiation fluence capable of forming all through holes at once. Therefore, in practice, the excimer laser light 190 that has passed through the mask 130 is reduced and projected by the projection lens 170, thereby increasing the irradiation fluence of the excimer laser light 190 on the surface of the glass substrate 120 and forming a through hole. Ensure irradiation fluence.

  By using the reduced projection by the projection lens 170, the cross-sectional area of the excimer laser light 190 on the surface of the glass substrate 120 is 1/10 with respect to the cross-sectional area of the excimer laser light 190 just after passing through the mask 130. If so, the irradiation fluence can be increased 10 times. An excimer immediately after generating the irradiation fluence of the excimer laser light on the surface of the glass substrate 120 by using a projection lens with a reduction ratio of 1/10 and the cross-sectional area of the excimer laser light being 1/100. It can be set to 100 times the laser beam.

  In FIG. 3, an example of the flow of the manufacturing method of the glass substrate for semiconductor device penetration electrode formation in this invention is shown roughly.

As shown in FIG. 3, the manufacturing method of the glass substrate for semiconductor device penetration electrode formation by the present invention is as follows.
(1) thickness of 0.01 mm to 5 mm, SiO ₂ content of a glass substrate of 50 wt% to 70 wt%, average thermal expansion coefficient of ^{10 × 10 -7 / K~50 × 10} -7 / K Preparing a glass substrate (step S110);
(2) placing the glass substrate on the optical path of the excimer laser light from the excimer laser light generator (step S120);
(3) disposing a mask having no through-opening on the optical path between the excimer laser light generator and the glass substrate (step S130);
(4) A step of irradiating the excimer laser light on the glass substrate along the optical path from the excimer laser light generator, whereby the through hole is formed in the glass substrate (step) S140).

  Hereinafter, each step will be described.

(Step S110)
First, a glass substrate having a thickness of 0.01 mm to 5 mm or less and a SiO ₂ content of 50 wt% to 70 wt%, having an average thermal expansion coefficient of 10 × 10 ⁻⁷ / K to 50 × 10 ⁻⁷ / A glass substrate of K is prepared. The preferred composition of the glass substrate is as described above.

(Step S120)
Next, the glass substrate is disposed on an optical path of excimer laser light from the excimer laser light generator. As shown in FIG. 2, the glass substrate 120 may be disposed on the stage 140.

The excimer laser beam 190 emitted from the excimer laser beam generator 110 can be used as long as the oscillation wavelength is 250 nm or less. From the viewpoint of output, a KrF excimer laser (wavelength 248 nm), an ArF excimer laser (193 nm), or an F ₂ excimer laser (wavelength 157 nm) is preferable. From the viewpoint of handling and glass absorption, an ArF excimer laser is more preferable.

  In addition, when an excimer laser beam 190 having a short pulse width is used, the thermal diffusion distance at the irradiated portion of the glass substrate 120 is shortened, and the thermal influence on the glass substrate can be suppressed. From this viewpoint, the pulse width of the excimer laser beam 190 is preferably 100 nsec or less, more preferably 50 nsec or less, and further preferably 30 nsec or less.

Further, the irradiation fluence of the excimer laser beam 190 is preferably 1 J / cm ² or more, and more preferably ² J / cm ² or more. If the irradiation fluence of the excimer laser beam 190 is too low, ablation cannot be induced and it becomes difficult to form a through hole in the glass substrate. On the other hand, when the irradiation fluence of the excimer laser beam 190 exceeds 20 J / cm ² , the glass substrate tends to be easily cracked or broken. The suitable range of the irradiation fluence of the excimer laser beam 190 varies depending on the wavelength range of the excimer laser beam 190 used, the type of glass substrate to be processed, etc., but in the case of a KrF excimer laser (wavelength 248 nm), 2 to 20 J / cm. ² is preferable. In the case of an ArF excimer laser (wavelength 193 nm), it is preferably ¹ to 15 J / cm ² .

  Unless otherwise specified, the value of the irradiation fluence of the excimer laser beam 190 means the value on the surface of the glass substrate to be processed. Moreover, such irradiation fluence shall mean the value measured using the energy meter on the processing surface.

(Step S130)
Next, a mask 130 having no through opening is disposed between the excimer laser light generator 110 and the glass substrate 120.

  As described above, the mask 130 is configured by forming a pattern of a reflective layer on a transparent substrate. The material of the transparent substrate is not particularly limited as long as it is transparent to the laser beam 190. The material of the transparent substrate may be, for example, synthetic quartz, fused quartz, Pyrex (registered trademark), soda lime glass, alkali-free glass, borosilicate glass, or the like.

On the other hand, the material of the reflective layer is not particularly limited as long as it has a property of efficiently blocking the laser light 190. The reflective layer may be made of a metal such as chromium, silver, aluminum, and / or gold, or a dielectric multilayer film, for example. Examples of the dielectric multilayer film include SiO ₂ , TiO ₂ , HfO ₂ , Ta ₂ O ₅ , Al ₂ O ₃ , Cr ₂ O ₃ , MgF ₂ , MgO, and ZrO ₂ .

  Further, the size of the mask 130, the shape and arrangement of the reflective layer pattern of the mask 130 are not particularly limited.

(Step S140)
Next, excimer laser light 190 is irradiated from the excimer laser light generator 110 to the glass substrate 120 through the mask 130.

  When irradiating the glass substrate 120 with the excimer laser light 190, the number of shots can be adjusted by adjusting the repetition frequency and irradiation time of the excimer laser light (shot number = repetition frequency × irradiation time).

It is preferable to irradiate the glass substrate 120 with the excimer laser light 190 so that the product of the irradiation fluence (J / cm ² ), the number of shots (times), and the thickness (mm) of the glass substrate is 1000 to 30000. .

This range depends on the type and properties of the glass substrate 120 (particularly presumed to be related to the glass transition temperature Tg), but is more preferably about 1000 to 20000, more preferably 2000 to 15000, and more preferably 3000. More preferably, it is -10000. This is because when the product of the irradiation fluence and the number of shots is within such a range, cracks are less likely to be formed. The irradiation fluence is preferably 1 to ²⁰ J / cm ² .

  Moreover, when the irradiation fluence of excimer laser light is large, the taper angle α tends to be small. Conversely, when the irradiation fluence is small, the taper angle α tends to increase. Therefore, by adjusting the irradiation fluence, a glass substrate having a through hole having a desired taper angle α can be obtained. The taper angle α may be in the range of 0.1 ° to 20 °.

  The glass substrate for semiconductor device penetration electrode formation can be manufactured according to the above process.

  In general, the semiconductor circuit fabrication wafer size is about 6 to 8 inches. Further, when the projection lens 170 performs reduction projection as described above, the processing area on the surface of the glass substrate is usually about several mm square. Therefore, in order to irradiate the entire region desired to be processed of the glass substrate 120 with the excimer laser light, it is necessary to move the excimer laser light or move the glass substrate 120 after processing at one place is completed. If anything, it is preferable to move the glass substrate 120 with respect to the excimer laser light. This is because there is no need to drive the optical system.

  In addition, when excimer laser light is irradiated onto the glass substrate 120, debris (scattered matter) may be generated. Moreover, when this debris accumulates inside the through hole, the quality and processing rate of the processed glass substrate may deteriorate. Therefore, debris may be removed by suction or blowing off simultaneously with laser irradiation to the glass substrate.

  Next, examples of the present invention will be described.

  A glass substrate having a plurality of through holes was manufactured by the following procedure using the manufacturing apparatus shown in FIG.

  First, as shown in FIG. 2, an excimer laser light generator 110 was arranged. Note that LPX Pro 305 (manufactured by Coherent) was used as the excimer laser light generator 110. This apparatus is capable of generating ArF excimer laser light having a maximum pulse energy of 0.6 J, a repetition frequency of 50 Hz, a pulse width of 25 ns, a generation beam size of 10 mm × 24 mm, and an oscillation wavelength of 193 nm.

Next, as shown in FIG. 2, a glass substrate 120 (AN100, manufactured by Asahi Glass Co., Ltd., SiO ₂ content 59 wt%) having a thickness of 0.3 mm and a thermal expansion coefficient of 38 × 10 ⁻⁷ / K is placed on a stage. 140. The glass substrate 120 can be moved to an arbitrary position on the upper surface of the stage 140.

  Next, a mask 130 was placed between the excimer laser light generator 110 and the glass substrate 120. FIG. 4 schematically shows the configuration of the mask 130 used.

  As shown in FIG. 4, the mask 130 used in this example is vapor deposition of chromium (Cr) on a part of the first surface 134 of a synthetic quartz substrate 132 having a length of 20 mm × width of 40 mm and a thickness of 1.5 mm. A film 135 is provided. The Cr vapor-deposited film 135 was placed in a region of 10 mm length × 24 mm width in the center of the first surface 134 of the synthetic quartz substrate 132.

  As shown on the right side of FIG. 4, the Cr vapor-deposited film 135 has an arrangement pattern in which circular Cr non-deposition portions 137 having a diameter of 0.5 mm are two-dimensionally arranged vertically and horizontally. The Cr non-deposited portions 137 were arranged vertically and horizontally at a pitch of 1.0 mm, 9 in the vertical direction and 23 in the horizontal direction.

  The Cr vapor deposition section 135 can reflect 99.9% of ArF excimer laser light. On the other hand, the Cr non-evaporation part 137 transmits 92% of ArF excimer laser light.

  Next, the projection lens 170 was disposed between the mask 130 and the glass substrate 120. The projection lens 170 is a lens having a focal length of 100 mm, the distance from the mask 130 on the optical path is 1100 mm, and the distance from the processing surface of the glass substrate 120 (the surface not in contact with the stage 140) is 110 mm. Arranged. In this case, the reduction ratio of the projection lens 170 is 1/10, and the mask pattern reduced to 1/10 is projected onto the glass substrate 120. That is, the excimer laser beam 190 generated by the excimer laser beam generator 110 with a beam size of 10 mm × 24 mm has a beam size of 1.0 mm × 2.4 mm when it reaches the processed surface of the glass substrate 120. (Area ratio = 1/100).

Before performing laser processing on the glass substrate 120, the irradiation fluence of the excimer laser light 190 on the processed surface of the glass substrate 120 was measured with an energy meter. As a result, the irradiation fluence was about 11 J / cm ^{2 at} maximum including the decrease due to the loss of the beam transmission system and the improvement due to the beam reduction.

Excimer laser light 190 was irradiated to the processed surface of the glass substrate 120 using such a manufacturing apparatus. At the time of irradiation, the laser beam 190 was adjusted with an attenuator so that the irradiation fluence on the processed surface of the glass substrate 120 was 5 J / cm ² .

Through the irradiation of the laser beam 190, 9 × 23 = 207 through-holes were simultaneously formed in the glass substrate 120. The irradiation time until penetrating was 78 seconds. The diameter of each obtained through-hole was about 50 μm, and the pitch was about 100 μm. The number density of the through holes was 86 / mm ² .

  The number of shots was obtained from the irradiation time from the start of the irradiation of the laser light 190 until the through hole was formed in the glass substrate 120. In this example, the repetition frequency of the excimer laser light used was 50 Hz, and the irradiation time until penetrating was 78 seconds. Therefore, the number of shots was calculated as 3900 times (78 seconds × 50 times = 3900 times).

  In the processed glass substrate 120, no crack or deformation was observed in appearance. Further, almost no residual stress was observed on the glass substrate 120.

  Thus, in this invention, since a several through-hole is formed simultaneously by irradiating a laser beam to a glass substrate, the glass substrate for semiconductor device penetration electrode formation can be manufactured easily. Moreover, even if the obtained glass substrate is laminated | stacked on a silicon wafer and it joins with this, it is hard to peel from a silicon wafer. Furthermore, when used as an interposer, problems such as deformation are unlikely to occur, and excellent device characteristics are expected to be exhibited.

  The method of the present invention is used as a method for producing a glass substrate that is suitably used for applications such as semiconductor device members, more specifically, insulating layers of multilayer circuit boards, wafer level packages, through holes for electrode extraction, and interposers. can do.

DESCRIPTION OF SYMBOLS 1 Glass substrate 1a 1st surface 1b 2nd surface 1c Wall surface 5 Through-hole 7 Wall surface 8a 1st opening 8b 2nd opening alpha taper angle L1 Diameter of 1st opening of through-hole L2 2nd of through-hole Diameter of opening 100 Manufacturing apparatus 110 Excimer laser light generator 120 Glass substrate 130 Mask 132 Synthetic quartz substrate 134 First surface of synthetic quartz substrate 135 Deposition film 137 Cr non-deposition portion 140 Stage 150 to 152 Mirror 160 Homogenizer 170 Projection lens 190 Excimer laser light.

Claims (7)

A method for producing a glass substrate for forming a semiconductor device through electrode,
(1) thickness of 0.01 mm to 5 mm, SiO ₂ content of a glass substrate of 50 wt% to 70 wt%, average thermal expansion coefficient of ^{10 × 10 -7 / K~50 × 10} -7 / K Prepare a glass substrate
(2) The glass substrate is disposed on an optical path of excimer laser light from an excimer laser light generator,
(3) A mask having no through-opening is disposed on the optical path between the excimer laser light generator and the glass substrate,
(4) A manufacturing method in which a through-hole is formed in the glass substrate by irradiating the excimer laser light to the glass substrate along the optical path from the excimer laser light generator.   The manufacturing method according to claim 1, wherein the mask having no through-opening is configured by providing a pattern of a reflective layer on a surface of a base material transparent to the excimer laser light. .   The reflective layer is configured by placing at least one metal of Cr (chrome), Ag (silver), Al (aluminum), and Au (gold) on the surface of the transparent substrate. The manufacturing method of Claim 2 characterized by these.   The manufacturing method according to claim 2, wherein the pattern of the reflective layer includes a portion where the reflective layer is provided and a portion where the substantially circular reflective layer is not provided. The step of irradiating the excimer laser beam, the excimer laser beam irradiation fluence is 2~20J / cm ^2, the irradiation fluence (J / cm ²⁾ and the number of shots (times) the thickness of the glass substrate ( 5. The method according to any one of claims 1 to 4, further comprising a step of irradiating so that a product of mm) is 1000 to 30000.   The taper-shaped through hole having a taper angle of 0.1 ° to 20 ° is formed in the glass substrate by the step of irradiating the excimer laser light. The manufacturing method as described in one. The manufacturing method according to claim 1, wherein the excimer laser light is any one of a KrF laser, an ArF laser, and an F ₂ laser.

Images