Method of manufacturing semiconductor element

Provided is a method of manufacturing a semiconductor element having at a cut portion with excellent quality, which minimizes a region on a silicon substrate necessary for cutting, and which prevents cutting water used when cutting by dicing is carried out from entering the semiconductor element. The method of manufacturing a semiconductor element includes: arranging, on the silicon substrate, multiple semiconductor element portions so as to be adjacent to one another; bonding the silicon substrate and a glass substrate together using the resin; and cutting the silicon substrate and the glass substrate, respectively, in a region in which the resin is provided, the cutting the silicon substrate and the glass substrate including: half-cutting the silicon substrate by dicing; cutting the glass substrate by scribing; and dividing the silicon substrate, the glass substrate, and the resin.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of manufacturing a semiconductor element, and more particularly, to a method of manufacturing a semiconductor element formed by bonding a silicon substrate and a glass substrate.

2. Description of the Related Art

At present, as a display element mounted on a display device such as a display, a reflective liquid crystal display element (LCOS), an organic light emitting element (organic electroluminescence (EL) element), and the like are actively researched and developed. When an LCOS or an organic light emitting element is manufactured, there are cases in which a step of bonding together a substrate (for example, a silicon substrate) on which elements are provided and a sealing substrate such as a glass substrate using a resin as an adhesive, that is, a sealing step, is included.

In the case of an LCOS, in the above-mentioned sealing step, not only the silicon substrate and the glass substrate are bonded together, but also a space between the silicon substrate and the glass substrate is filled with a liquid crystal material. Specifically, the silicon substrate and the glass substrate are bonded together using a resin sealing material provided at peripheral portions of each of the substrates, and a space between the two substrates and inside the resin seal material is filled with the liquid crystal material. In the case of an organic EL element, the above-mentioned sealing step is carried out for the purpose of blocking the organic EL element from outside air. Specifically, the silicon substrate (substrate) and the glass substrate (sealing substrate) are bonded together using a filling resin so as to cover at least the entire surface of a light emitting region, and the organic light emitting element is enclosed with the silicon substrate, the glass substrate, and the filling resin to protect the organic light emitting element from oxygen and moisture in the atmosphere.

By the way, when a semiconductor element is manufactured, from the viewpoint of production efficiency, a mother board on which multiple semiconductor elements are arranged is used. When such a mother board is used to manufacture a semiconductor element, the semiconductor element is manufactured specifically through the following steps (a) to (c): (a) a step of manufacturing multiple semiconductor elements on the mother board; (b) a step of bonding together and integrating the mother board and a glass substrate (sealing substrate) having substantially the same the size as the mother board using a resin, thereby sealing all the semiconductor elements provided on the mother board; and (c) a step of separating the semiconductor elements one by one by cutting the mother board and the glass substrate.

By the way, as a method of dividing a structure formed by bonding together a silicon substrate as a mother board and a glass substrate as a sealing substrate using a resin, for example, there is known collective cutting of the silicon substrate, the glass substrate, and the resin by dicing.

In this case, when the silicon substrate, the glass substrate, and the resin are simultaneously cut by dicing, clogging occurs because a dicing blade used strikes the resin. This clogging conspicuously reduces the dicing quality (in particular, increases chippings). Therefore, in order to maintain the dicing quality at a certain level, it is necessary to increase the replacement frequency of the dicing blade. Further, generally, the thickness of a dicing blade which can cut both silicon and glass is larger than the thickness of a dicing blade used only for silicon. Therefore, a region on the silicon substrate which is necessary for cutting the silicon substrate (cutting street) becomes larger, which results in the reduced number of semiconductor elements taken from one mother board.

Further, when dicing is carried out at a portion in which there is no resin between the silicon substrate and the glass substrate, a problem may arise that cutting water used in the dicing enters together with particles to contaminate the elements provided on the silicon substrate with the particles.

As a method of solving the above-mentioned problem which arises when a substrate is cut, Japanese Patent Application Laid-Open No. 2008-164980 proposes a method in which, when the silicon substrate and the glass substrate are cut at a portion having the resin therebetween, the cutting method is changed. Specifically, there is proposed a method in which, while the glass substrate and the resin are completely cut by dicing, the silicon substrate is half-cut by dicing.

However, even the method proposed in Japanese Patent Application Laid-Open No. 2008-164980 still cuts the resin itself by dicing, and, similarly to the case of the conventional art, the above-mentioned reduction of the dicing quality is inevitable. Further, in order to completely cut the glass substrate and the resin by dicing, it is necessary to dice to some extent an interface of the silicon substrate with the resin, and the above-mentioned dicing blade which can cut both silicon and glass is required to be used. Further, when a part of the cut portion does not include the resin therein, cutting water enters the portion which does not include the resin therein.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above-mentioned problems. An object of the present invention is to provide a method of manufacturing a semiconductor element having a cut portion with excellent quality, which minimizes a region on a silicon substrate necessary for cutting, and which prevents cutting water used when cutting by dicing is carried out from entering the semiconductor element.

According to an exemplary embodiment of the present invention, there is provided a method of manufacturing a semiconductor element, the semiconductor element including: a silicon substrate; a semiconductor element portion provided on the silicon substrate; and a sealing member for sealing the semiconductor element portion, the sealing member including a glass substrate provided so as to be opposed to a surface of the silicon substrate having the semiconductor element portion provided thereon, and a resin for bonding the silicon substrate and the glass substrate, the method including: arranging, on the silicon substrate, multiple semiconductor element portions so as to be adjacent to one another; bonding the silicon substrate and the glass substrate together using the resin; and cutting the silicon substrate and the glass substrate, respectively, in a region in which the resin is provided, the cutting the silicon substrate and the glass substrate including: half-cutting the silicon substrate by dicing; cutting the glass substrate by scribing; and dividing the silicon substrate, the glass substrate, and the resin after the dicing and the scribing are carried out, in which an amount of remainder of half-cut in the half-cutting the silicon substrate is 20 μm or more and 100 μm or less.

According to the present invention, it is possible to provide the method of manufacturing a semiconductor element having a cut portion with excellent quality, which minimizes the region on the silicon substrate necessary for cutting, and which prevents the cutting water used when cutting by dicing is carried out from entering the semiconductor element.

Specifically, according to the method of manufacturing a semiconductor element of the present invention, the resin is not diced, and thus, clogging of a dicing blade with the resin does not occur, and the quality of a cut portion becomes excellent, and, in particular, chippings of the silicon substrate can be reduced.

Further, according to the method of manufacturing a semiconductor element of the present invention, in dicing, a dicing blade used only for the silicon substrate can be used, and thus, a thin blade can be used. Therefore, a region on the silicon substrate, which is necessary for cutting, can be minimized.

Still further, in dicing, even when the silicon substrate is cut in a region without the resin, the cutting water used in dicing does not enter a space between the silicon substrate and the glass substrate, and thus, it is not necessary to change the cutting method between a portion with the resin and a portion without the resin. Accordingly, the steps can be simplified.

DESCRIPTION OF THE EMBODIMENTS

A manufacturing method according to the present invention is a method of manufacturing a semiconductor element including: a silicon substrate; a semiconductor element portion provided on the silicon substrate; and a sealing member for sealing the semiconductor element portion.

Further, according to the present invention, the sealing member includes a glass substrate provided so as to be opposed to a surface of the silicon substrate having the semiconductor element portion provided thereon, and a resin for bonding the silicon substrate and the glass substrate.

The method of manufacturing a semiconductor element according to the present invention includes the following steps (1) to (3): (1) a step of arranging on the silicon substrate multiple semiconductor element portions so as to be adjacent to one another (semiconductor element portion forming step); (2) a step of bonding the silicon substrate and the glass substrate together using the resin (bonding step); and (3) a step of cutting the silicon substrate and the glass substrate in a region in which the resin is provided (substrate cutting step).

Further, according to the present invention, the above-mentioned substrate cutting step (3) includes the following steps (3-1) to (3-3): (3-1) a step of half-cutting the silicon substrate by dicing; (3-2) a step of cutting the glass substrate by scribing; and (3-3) a step of dividing the silicon substrate, the glass substrate, and the resin after the dicing and the scribing are carried out.

Note that, according to the present invention, it is preferred to, after carrying out the step (3-1), divide the silicon substrate, and then carry out the step (3-2).

A semiconductor element manufactured by the manufacturing method according to the present invention refers to an electronic element having a member formed of an inorganic semiconductor or an organic semiconductor. Further, the semiconductor element includes as a matter of course an electronic element having a member formed of an inorganic semiconductor and a member formed of an organic semiconductor, and an electronic element having a member formed by combining an inorganic semiconductor and an organic semiconductor. Specifically, an organic light emitting element, an LCOS, and the like are included.

The method of manufacturing a semiconductor element according to the present invention is described in the following by means of embodiments with appropriate reference to the attached drawings. Note that, the embodiments of the present invention described in the following are merely exemplary, and the present invention is not limited thereto and various applications and modifications are possible within the above-mentioned gist of the present invention.

FIG. 1is a perspective view illustrating an exemplary semiconductor element manufactured by a method of manufacturing a semiconductor element according to the present invention. Note that, an exemplary semiconductor element1illustrated inFIG. 1is, for example, an organic light emitting element, but the present invention is not limited thereto.

The semiconductor element1illustrated inFIG. 1includes a silicon substrate10, a display portion11provided on the silicon substrate10in the center of the silicon substrate10, and an electrode pad12provided on the silicon substrate10along an edge on one side of the silicon substrate10.

Further, in the semiconductor element1illustrated inFIG. 1, the display portion11is sealed by a glass substrate13and a resin14. Note that, according to the present invention, to “seal” as used herein means, for example, to bond the silicon substrate10and the glass substrate13together after the resin14is applied onto the display portion11and onto the silicon substrate10around the display portion11, as illustrated inFIG. 1. However, in the present invention, the specific form of the sealing is not limited to the one illustrated inFIG. 1. For example, the silicon substrate10and the glass substrate13may be bonded together after the resin14is selectively applied only onto the silicon substrate10around the display portion11under an atmosphere of an inert gas such as a nitrogen gas. In other words, the resin14used in the sealing is not necessarily required to be applied onto the display portion11.

On the other hand, in the semiconductor element1illustrated inFIG. 1, the electrode pad12is connected to wiring from the outside using wire bonding or the like. Therefore, the glass substrate13as a sealing member is required to be removed from the electrode pad12if possible, and thus, it is necessary not to provide the resin14on the electrode pad12.

By the way, when the multiple semiconductor elements1illustrated inFIG. 1are manufactured, from the viewpoint of production efficiency, there is adopted a method in which multiple display portions are formed on a large-sized silicon substrate (mother board), the respective display portions are sealed using the glass substrate and the resin, and then, cutting is carried out to separate the respective elements one by one.

FIG. 2is a schematic plan view illustrating a specific example of a bonded substrate used when the semiconductor element illustrated inFIG. 1is manufactured. Note that, inFIG. 2, like reference numerals are used to designate like members in the semiconductor element illustrated inFIG. 1. A bonded substrate15illustrated inFIG. 2includes the silicon substrate10which is circular, the glass substrate13in the same shape as that of the silicon substrate10, and the resin14for bonding the silicon substrate10and the glass substrate13together. Further, on the silicon substrate10illustrated inFIG. 2, the multiple display portions (not shown) and the multiple electrode pads (not shown) forming the semiconductor elements illustrated inFIG. 1are respectively provided in predetermined regions. By the way, in the bonded substrate15illustrated inFIG. 2, the resin14is not applied onto the entire surface of the silicon substrate10, but is applied so as to avoid the electrode pads (not shown) forming the semiconductor elements illustrated inFIG. 1, and regions therearound, specifically, so as to avoid regions16. By limiting the application regions of the resin14in this way, the resin14is prevented from being applied onto the electrode pads12forming the semiconductor elements1illustrated inFIG. 1.

Next, steps of manufacturing the semiconductor element1illustrated inFIG. 1through the manufacture of the bonded substrate15illustrated inFIG. 2are described.

(1) Semiconductor Element Portion Forming Step

First, multiple semiconductor element portions are arranged on the silicon substrate10so as to be adjacent to one another. The semiconductor element portion as used herein refers to a group of members such as the display portion11and the electrode pad12which form the semiconductor element illustrated inFIG. 1and which are formed on the silicon substrate10. Further, by providing multiple semiconductor element portions in which structural members and arrangement thereof are the same with cutting lines LAand LBdescribed below being boundary lines, the multiple semiconductor element portions provided on the silicon substrate10are arranged so as to be adjacent to one another.

Next, the silicon substrate10and the glass substrate13are bonded together using the resin14. The method of bonding the silicon substrate10and the glass substrate13together is not specifically limited. However, as described above, after the resin14is applied so as to avoid the electrode pads (not shown) forming the semiconductor elements, and regions therearound, the silicon substrate10and the glass substrate13are bonded together.

In this step, it is preferred to use a resin which is cured after the silicon substrate10and the glass substrate13are bonded together because division of the substrates in the subsequent step can be carried out easily. Exemplary preferred resins used in the present step (bonding step) include a thermosetting epoxy resin, a thermosetting acrylic resin, an ultraviolet curable epoxy resin, and an ultraviolet curable acrylic resin.

(3) Substrate Cutting Step

Next, the silicon substrate and the glass substrate are respectively cut in regions in which the resin is provided. In this case, when the silicon substrate and the glass substrate are cut, the silicon substrate10, the glass substrate13, or the resin14is cut along, for example, three kinds of cutting lines illustrated inFIG. 2, that is, LA, LB, and LC. Specifically, the silicon substrate10, the glass substrate13, and the resin14are cut along the cutting line LA. The silicon substrate10and the glass substrate13are cut along the cutting line LB. Further, only the glass substrate13is cut along the cutting line LC. In this way, at least 54 semiconductor elements1are obtained from the bonded substrate15illustrated inFIG. 2. Further, the silicon substrate and the glass substrate are cut in regions in which the resin14is provided, and thus, there is a reduced possibility that the display portion (not shown inFIG. 2) sealed by the glass substrate13and the resin14and included in the semiconductor element is exposed when the silicon substrate or the glass substrate is cut.

A specific method of cutting the silicon substrate and the glass substrate is now described in detail with appropriate reference to the attached drawings.FIG. 3is a partial enlarged view illustrating a region surrounded by broken lines inFIG. 2(designated by a reference numeral2).FIG. 4Ais a schematic sectional view taken along the line4A-4A ofFIG. 3, andFIG. 4Bis a schematic sectional view illustrating a state after the cutting. Further,FIG. 5Ais a schematic sectional view taken along the line5A-5A ofFIG. 3, andFIG. 5Bis a schematic sectional view illustrating a state after the cutting.

Further, according to the present invention, the above-mentioned substrate cutting step (3) includes the following steps (3-1) to (3-3): (3-1) a step of half-cutting the silicon substrate by dicing; (3-2) a step of cutting the glass substrate by scribing; and (3-3) a step of dividing the silicon substrate, the glass substrate, and the resin, which are included in the bonded substrate, after the dicing and the scribing are carried out.

In this embodiment, the silicon substrate is half-cut by dicing along the cutting lines LAand LBillustrated inFIG. 3. Note that, dicing is carried out with respect to a surface which is opposite to a surface opposed to the glass substrate13of the two surfaces of the silicon substrate10.

When the silicon substrate10is half-cut by dicing, the depth of the half cut of the silicon substrate10is not specifically limited insofar as the depth enables the silicon substrate10to be divided when stress is applied thereto. However, a diagonal crack may develop in the silicon substrate when divided (broken), and thus, in order to enhance the positional accuracy of the division, it is preferred to cause the depth of the half-cut of the silicon substrate10to be as large as possible. An experiment was conducted on the relationship between the depth of the half-cut, the division accuracy, and the division quality. The results are shown in Table 1.

For example, it can be found that, when the amount of remainder of the half-cut which is the thickness of the silicon substrate10minus the depth of the half-cut of the silicon substrate10is 20 μm or more and 100 μm or less, chippings are not generated, and hence this case is preferred. Further, it is more preferred that the amount of remainder of the half-cut be 20 μm or more and 75 μm or less because the division accuracy can be high. When the amount of remainder of the half-cut is more than 100 μm, it becomes difficult to divide the silicon substrate10. When the division is performed by force, chippings are generated, and at the same time, the positional fluctuations of the division become large. Therefore, the cutting street may become larger. On the other hand, when the amount of remainder of the half-cut is less than 20 μm, the silicon substrate10is easily broken in dicing or when the substrate is handled, and the division cannot be controlled.

When the silicon substrate10is half-cut by dicing as illustrated inFIG. 4AandFIG. 5A, it is desired that the thickness of a dicing blade21used be as small as possible for the purpose of inhibiting the chippings and minimizing the region on the silicon substrate10which is necessary for the cutting. However, when the thickness of the dicing blade21is too small, the durability of the blade itself is insufficient, which may become a cause of breakage of the blade when dicing is carried out. The thickness of the dicing blade21used according to the present invention is preferably 15 μm or more and 60 μm or less, and more preferably, 25 μm or more and 50 μm or less.

For example, when the dicing blade21having a thickness of 34 μm is used, it is possible to cause the width of the cutting region of the silicon substrate10including the chippings to be 70 μm or less.

In this embodiment, the glass substrate13is cut by a scriber22illustrated inFIG. 4AandFIG. 5Aalong the cutting lines LA, LB, and LCillustrated inFIG. 3. In this case, when the glass substrate is cut by the scriber22, it is desired to develop a vertical crack caused by the scriber22as deep as possible. For example, by using a scribing wheel Penett (trademark) manufactured by Mitsuboshi Diamond Industrial Co., Ltd., a vertical crack can be developed as deep as possible. Note that, scribing of the glass substrate13along the cutting line LCmay be carried out before the glass substrate13is divided along the cutting lines LAand LB, or after the division.

After half-cutting of the silicon substrate10and cutting of the glass substrate13are carried out, the silicon substrate10, the glass substrate13, and the resin14are divided along the half-cut places (21aand21b) or along the cut places (22a,22b, and22c). Specifically, as illustrated inFIG. 4BandFIG. 5B, by pressurization from the glass substrate13side (toward the silicon substrate10) along the cutting lines (LAand LB), stress is applied in a direction in which a groove formed by half-cutting the silicon substrate10expands. This pressurization enables division of the silicon substrate10, the glass substrate13, and the resin14under a state in which chippings of the silicon substrate10are inhibited.

In this embodiment, processing shown in Table 2 below is carried out along the cutting lines (LA, LB, and LC). The silicon substrate10, the glass substrate13, or the resin14is divided along the cutting lines.

Through the steps described above, a semiconductor element having a cut portion with excellent quality illustrated inFIG. 1can be manufactured.

In this embodiment, a semiconductor element is manufactured in a way similar to that of Embodiment 1 except that, after the silicon substrate is half-cut by dicing, the silicon substrate10is divided, and then the glass substrate is cut by scribing. Specifically, after the silicon substrate is half-cut by dicing, stress is applied in a direction in which a groove formed by half-cutting expands, to thereby develop a crack in a thickness direction in a part of the silicon substrate10which is not subjected to the half-cutting and divide the silicon substrate10. After that, the glass substrate13is scribed. Other points are similar to those of Embodiment 1.

As described above, by dividing the silicon substrate10before the scribing, chippings of the silicon substrate10can be further inhibited. Therefore, a semiconductor element having a cut portion with more excellent quality can be obtained.

As described above, according to the present invention, it is possible to manufacture a semiconductor element, such as an organic EL display element, which has a cut portion with more excellent quality as compared with a conventional one. “Having a cut portion with excellent quality” as used herein specifically means that, for example, chippings of the silicon substrate are inhibited, a region on the silicon substrate which is necessary for the cutting is reduced, cutting water is prevented from entering into a space between the silicon substrate and the glass substrate in dicing, and the positional accuracy of dividing the glass substrate is improved.

This application claims the benefit of Japanese Patent Application No. 2011-270895, filed Dec. 12, 2011, which is hereby incorporated by reference herein in its entirety.