JP2010010299A - Method of manufacturing chip made of brittle material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of inexpensively manufacturing a chip made of a brittle material like a semiconductor chip in good yield by using a brittle ingot protected with an embedding resin when the chip made of the brittle material like the semiconductor chip is manufactured from the brittle ingot like a semiconductor ingot. <P>SOLUTION: The method of manufacturing the chip made of brittle material includes an embedding process of embedding the brittle ingot in the embedding resin, a slicing process of slicing the embedded brittle ingot to form a wafer, and a cutting process of cutting the wafer into chips. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a chip made of a brittle material for obtaining a brittle chip such as a semiconductor chip by slicing, metalizing, and cutting a brittle ingot such as a semiconductor ingot into chips.

  Conventionally, a chip made of a brittle material has been subjected to slicing and chip cutting after forming an ingot and then grinding to adjust the outer shape of the ingot, as described in Patent Document 1 below. . A conventional general manufacturing method of a semiconductor chip will be described with reference to FIG.

  Conventional semiconductor chips have been obtained, for example, by the following processes.

  First, the melt raw material 2 filled in the crystal growth container 1 is heated and melted while moving the heater 3 in the direction of the arrow, so that an ingot is obtained while melting the low purity portion on the front side to be heated. A semiconductor ingot 10 is formed by the method (FIG. 9A). Then, after grinding so that the outer peripheral shape of the obtained semiconductor ingot 10 becomes a predetermined outer diameter, it is transferred to a table and fixed to a jig for slicing, and as shown in FIG. 9B. Slicing is performed with a slicer 16 or a wire saw to obtain a semiconductor wafer 120 (FIG. 9B). Next, in order to enable the main surface of the obtained semiconductor wafer 120 to be soldered, a metallizing process, which is a surface treatment for forming a metal thin film 121 such as nickel or gold by sputtering, vapor deposition, or plating, is performed ( FIG. 9C). Finally, the metallized semiconductor wafer is cut into chips by a dicer 16 or a wire saw to obtain a semiconductor chip 130 (FIG. 9D).

  In the conventional method of manufacturing a semiconductor chip as described above, when a semiconductor wafer is manufactured by slicing a semiconductor ingot, which is a brittle material, the outer shape of the ingot is adjusted to a predetermined shape and the semiconductor ingot is fixed in advance. A method of cutting a slice after fixing it to a fixing jig for fixing by means of wax fixation or freezing fixation has been used. Further, when the semiconductor wafer obtained as described above is cut into chips to obtain a semiconductor chip, the semiconductor wafer is fixed on the table with tape or wax, or frozen and fixed. Later, methods such as cutting have been used.

However, according to the method as described above, since the semiconductor ingot is a brittle material, there is a problem in that the yield of the semiconductor chip is lowered due to frequent occurrence of cracks and chips due to stress at the time of cutting. In particular, when there are many cracks made in the manufacturing process in the original semiconductor ingot to be processed, in the cutting process for slicing and the chip forming process for obtaining a semiconductor chip, the crack grows and most of them are cracked. It sometimes happened. In addition, the outer diameter of the resulting ingot is generally low in shape accuracy and is often indefinite. Therefore, if the outer shape of the obtained semiconductor ingot is not processed by cutting it, it is stable to the fixture. And could not be fixed. Moreover, even when a semiconductor wafer is obtained, when the obtained semiconductor is transferred to a subsequent process, a phenomenon in which an impact is applied to cause cracking or chipping often occurs, resulting in a decrease in yield. .
JP 07-321071 A

  When manufacturing a chip such as a semiconductor chip from a brittle ingot such as a semiconductor ingot, the present invention uses a brittle ingot protected by an embedding resin, so that a chip such as a semiconductor chip can be obtained at a high yield and at a low cost. It aims at providing the manufacturing method which can be manufactured.

  As a result of intensive studies to solve the above-described conventional problems, the present inventors have found that the problem can be solved by the following means.

  That is, the chip manufacturing method of the brittle material of the present invention includes an embedding step of embedding the brittle ingot with an embedding resin, a slicing step of slicing and cutting the embedded brittle ingot, And a cutting step of cutting the wafer into chips. According to such a manufacturing method, since the brittle ingot is subjected to slicing or chip processing in a state protected by the embedding resin, it is possible to suppress the occurrence of cracks and the like due to an extra load applied to the brittle ingot. . In addition, even if the brittle ingot to be processed is irregular, the shape of the outer periphery can be adjusted by the embedding resin, so that the fixing to the jig is stabilized and the shape variation between the ingots to be processed is reset. can do. Thereby, since the cutting quality is improved, the yield of the obtained chip is improved. In addition, in the case of transferring the obtained wafer from the previous process to the subsequent process, by holding the embedded resin fragment around the wafer, it can be transferred without contacting the wafer body. This also contributes to an improvement in handling properties such that the wafer surface is less likely to be damaged.

  Further, as the embedded brittle ingot, when a convex portion made of an embedding resin is provided around the embedding brittle ingot so as to be parallel to the longitudinal direction of the brittle ingot, the handling property is further improved. To preferred.

  Further, as the embedded brittle ingot, it is preferable that a plurality of rod-shaped brittle ingots are embedded in parallel in the longitudinal direction from the viewpoint of improving productivity, and in this way According to the embedding of a plurality of ingots, the ingots reinforce each other so that they are less affected by mechanical force from the outside, so that the occurrence of cracks and cracks is further reduced. It is preferable from the point.

  In the above manufacturing method, a part of the embedding resin existing in the gap between the brittle ingots is removed by cutting so as to form an opening hole. This is preferable from the viewpoint that the clogging of the resin can be suppressed and the cutting quality can be further improved.

  In addition, each of the above manufacturing methods preferably further includes a non-defective product separation step of separating the non-defective chip and a cut piece other than the non-defective chip by a specific gravity difference after the cutting step. According to such a method, a non-defective product can be easily separated by omitting troublesome work such as visual separation.

  Further, in each of the above manufacturing methods, the embedded resin is a porous resin, the amount of resin to be cut is reduced, the resin clogging of the blade during cutting is suppressed, and the cutting quality is further improved. In addition, it is preferable to separate non-defective products by the specific gravity difference from the viewpoint that the accuracy of separation is further increased.

  Moreover, in each said manufacturing method, it is preferable from the point with easy embedding that the said embedding resin is a liquid thermosetting resin or a liquid photocurable resin. In particular, epoxy resin is excellent in heat resistance and corrosion resistance, so deformation or dissolution occurs in the metallizing process, which is a pretreatment for enabling soldering. It is preferable from a difficult point.

  Moreover, in each said manufacturing method, when it further comprises the metallizing process which metallizes the said semiconductor wafer between the said slicing process and a cutting process, it is excellent also in the handleability in the case of a metalizing process. preferable.

  According to the manufacturing method of the present invention, since it is possible to perform cutting by suppressing an extra load on the brittle ingot, the occurrence of cracks and the like can be suppressed. In addition, even if the brittle ingot to be processed is irregular, the shape of the outer periphery can be adjusted by the embedding resin, so that the fixing to the jig is stabilized and the shape variation between the ingots to be processed is reset. can do. Thereby, since the cutting quality is improved, the yield of the obtained chip is improved. In the case where the wafer is transferred from the previous process to the subsequent process, it is possible to transfer the wafer without contacting the wafer body by holding the embedded resin fragment around the wafer. It becomes hard to be damaged.

  In the present embodiment, an example of manufacturing a semiconductor chip as a chip made of a brittle material will be described as a representative example with reference to the drawings.

  The manufacturing method of the present invention includes the following steps.

  First, the melt raw material 2 for obtaining an ingot is filled in the crystal growth vessel 1 by the zone melt method, and after the vessel 1 is sealed, the heater 3 is moved from the lower portion to the upper portion of the crystal growth vessel 1. The melt raw material 2 is sequentially heated and melted and solidified while being moved to obtain a semiconductor ingot which is a brittle ingot 10 (FIG. 1A). In the present invention, the method for producing a brittle ingot is not limited to the above-described method. For example, the brittle ingot obtained by sintering after compression molding a powder material for obtaining the brittle ingot is also particularly limited. It can be used without.

As brittle ingots, thermoelectric conversion materials having a bismuth-tellurium hexagonal structure,
An inorganic ingot such as a semiconductor ingot made of a gallium-arsenic (Ga-As) -based material, a silicon ingot, or a ceramic ingot such as a glass ingot is used without particular limitation.

  Next, the obtained ingot 10 is embedded with the embedding resin 11 (FIG. 1B).

  As a method for embedding an ingot with an embedding resin, for example, a rod-shaped ingot is disposed at the center of a mold 12 such that a cylindrical mold as shown in FIG. A method of pouring a liquid thermosetting resin into a mold and heating it in a state in which is closed. At this time, the ingot is hung, or a guide is provided in advance in the lower mold, and the ingot is arranged so as to be positioned at the center of the cylindrical mold. As another method, a rod-shaped ingot 10 is disposed at the center of a mold having a cylindrical recess as shown in FIG. 2, and in this state, a liquid thermosetting resin is poured into the mold. And a method of coating with the embedding resin 11 by heating and curing. The material of the mold is not particularly limited, but a mold made of various metals or various resins is used, but it is particularly preferable to use a mold made of a fluororesin from the viewpoint of releasability and heat resistance. Moreover, in order to improve mold release property, it is preferable to apply a mold release agent to the mold inner surface in advance. For embedding with the embedding resin, it is not essential to completely cover the ingot 10, and for example, the tip portion of the rod-shaped ingot may not be covered.

  Further, as shown in FIG. 3 (A), when a convex portion 11A made of an embedding resin was provided around the ingot so as to be parallel to the longitudinal direction of the ingot, it was obtained by slicing described later. A handle 11B made of an embedding resin as shown in FIG. 3B is formed around the wafer. The handle 11B formed in this way is preferable because it can be handled without directly contacting the wafer body when the wafer is transferred in each subsequent process.

  Further, when embedding a brittle ingot with an embedding resin, a plurality of ingots are embedded in parallel in the longitudinal direction to embed a plurality of ingots into a slicing step, a metalizing step, a chip, which will be described later. It is preferable from the point that productivity can be greatly increased because the cutting step of cutting into a shape can be processed at a time. In addition, by embedding a plurality of ingots in this way, the ingots reinforce each other so that they are less susceptible to external mechanical forces. This is preferable from the viewpoint of reducing the generation.

  As a specific example of an embedding pattern in which a plurality of rod-like ingots are embedded in parallel in the longitudinal direction, for example, three ingots are embedded in a substantially triangular shape as shown in FIG. The pattern can be freely selected, for example, nine ingots are embedded in a substantially square shape as shown in FIG. In addition, when a plurality of rod-shaped ingots are embedded in this way, the cutting area is increased, so that the cutting speed may be reduced. In such a case, a part of the embedding resin is removed by cutting. Specifically, as shown in FIG. 5A, the substantially triangular periphery formed by the embedding resin 11 is surrounded by the rod-shaped ingot 10. The embedding resin 11 is cut and removed along the periphery, or the embedding resin 11 is removed by cutting so as to open the opening hole 15 in the gap between the three ingots 10, or formed by the embedding resin 11 as shown in FIG. The periphery of the substantially square-shaped embedding resin 11 is removed by cutting along the periphery of the rod-shaped ingot 10, and the embedding resin 11 is also removed by cutting so that the opening hole 15 is opened in the gap between the nine ingots. By doing so, it is possible to reduce the ratio of the embedding resin that causes the cutting speed to decrease, and to reduce the occurrence of clogging of the embedding resin into the cutting blade.

  The above-mentioned peripheral cutting can be removed by machining with a drill or the like, and the opening hole is also cut with a drill or the like, and a rod is embedded in advance during resin embedding, and the rod is removed after the embedding resin is cured. A method of pulling out may be used.

  Furthermore, even in an embedding pattern in which a plurality of rod-like ingots are arranged in parallel in the longitudinal direction, a handle portion 11B may be provided as shown in FIGS.

  As the embedding resin, various liquid thermosetting resins and various liquid photocurable resins can be preferably used. In addition, when using liquid photocurable resin, it is preferable to use a transparent type.

  As the thermosetting resin or photocurable resin, an unsaturated polyester resin, an epoxy resin, or the like can be used. In particular, an epoxy resin is excellent in heat resistance and corrosion resistance. In the case of metallizing treatment, which is a pretreatment for enabling soldering, it is preferable from the point that deformation and dissolution are unlikely to occur.

  Further, as the embedding resin, a porous resin, specifically, a rigid polyurethane foam or the like may be used. When such a porous resin is used, the resin ratio can be reduced by adjusting the porosity, and after forming a chip by a cutting process described later, a good brittle chip and the good product This is preferable because it is easy to separate the cut piece other than the brittle tip by the specific gravity difference.

  Next, the embedded ingot is fixed to a table with a jig for slicing, and slicing with a slicer 16 or a wire saw as shown in FIG. At this time, since the ingot 10 to be sliced is covered with the embedding resin 11 and fixed from its periphery, the ingot 10 may be cracked or chipped due to vibration of the cutting blade due to vibration of the cutting blade during slicing, or in the ingot 10. The growth of cracks existing in the substrate can be suppressed.

  Next, a metallizing process, which is a surface process for forming a metal thin film 21 on the surface of the wafer 20 is performed so that the surface of the obtained wafer 20 can be soldered (FIG. 1D).

  In the metallizing process, a process for forming a thin film of nickel, gold or the like using a known metal thin film forming method such as a sputtering method, a vapor deposition method, a CVD method, or a plating method is performed. At this time, in metallizing treatment by various film forming methods, handling such as sputtering method, vapor deposition method, transfer of wafer to film forming table in CVD method or fixing to jig, immersion in plating bath at the time of plating method, etc. In this case, since it can be fixed by the embedding resin portion without using the surface of the wafer, it is possible to avoid direct contact with the wafer surface, thereby preventing oil and dust from adhering to the wafer. It is possible to suppress the film formation failure.

  And the chip | tip 30 cut | disconnected is obtained by cut | disconnecting the wafer 20 finally metallized in chip shape with the dicer 16 or a wire saw (FIG.1 (E)). Also in this cutting process, when the wafer 20 is fixed on the table of the dicer 16 or the wire saw with a jig, it can be fixed not by the surface of the wafer 20 but by the embedded resin portion. Since direct contact can be avoided, adhesion of oil and dust to the wafer 20 can be suppressed, and damage to the wafer 20 can be suppressed.

  In the fragment obtained in the cutting step, non-defective chips 30A obtained from the central portion and cut pieces 30B other than non-defective chips in the peripheral portion are mixed as shown in FIG. Conventionally, such a non-defective chip 30A and a cut piece 30B which is a defective chip in the peripheral portion have been sorted and separated by visual observation. On the other hand, according to the manufacturing method of the present invention, the non-defective chip 30A maintains the standardized shape as shown in FIG. 8 (A), whereas the end as shown in FIG. 8 (B). The defective cut piece 30B, which is a material, is indefinite, and has a form in which the embedding resin 11 is attached around the chip piece 31 made of an ingot material. Usually, since the specific gravity of the ingot material is higher than that of the embedding resin 11, the non-defective chip 30 </ b> A is separated from the defective chip 30 </ b> B by the specific gravity difference by immersing all pieces in a predetermined liquid. be able to. In particular, when a porous resin is used as the embedding resin 11 as described above, the specific gravity difference from the ingot material can be further increased, so that the accuracy of separation can be further improved. it can.

  As the separation method based on the difference in specific gravity, the above-described sedimentation separation, centrifugation, or the like can be used. Centrifugation is preferable in that it can be separated in a short time, but sedimentation separation is more preferable because the chip may be damaged. Note that the specific gravity of the liquid used in the case of sedimentation separation should be close to the specific gravity of the embedding resin and smaller than the specific gravity of the ingot material in consideration of the specific gravity of the ingot material and the specific gravity of the embedding resin. desirable.

  The above-described method for manufacturing a chip made of a brittle material according to the present invention can be preferably used for manufacturing various semiconductor elements and ceramic chips, particularly thermoelectric conversion elements.

It is explanatory drawing which shows the manufacturing method of embodiment of this invention. It is a schematic diagram which shows the example of the method of embedding an ingot with embedding resin. It is explanatory drawing which shows the method of forming the embedding resin part used as a handle in an ingot. It is explanatory drawing which shows the embedding pattern which arranges and embeds several rod-shaped ingots in parallel with a longitudinal direction. It is explanatory drawing which shows the form which reduces the embedding resin ratio of the embedding ingot which aligned and embedded the multiple rod-shaped ingot in parallel with the longitudinal direction. It is explanatory drawing which shows the form which formed the embedding resin part used as a handle in the case where a plurality of rod-shaped ingots were embedded in parallel in the longitudinal direction. It is explanatory drawing explaining the chip | tip piece obtained in the cutting process. It is the model explanatory drawing which expanded and showed the quality-goods chip | tip obtained in the said cutting process, and the cut piece which is a defective chip. It is explanatory drawing which shows the manufacturing method of the conventional semiconductor chip.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Crystal growth container 2 Raw material for melt 3 Heater 10 Ingot 11 Embedding resin 11A Convex part 11B Handle 12 Type 15 Open hole 16 Slicer (Dicer)
20 Wafer 21 Metal thin film 30 Chip 30A Non-defective chip 30B Cut piece 31 Chip fragment

Claims (10)

  An embedding step of embedding a brittle ingot with an embedding resin, a slicing step of slicing and cutting the embedded brittle ingot to form a wafer, and a cutting step of cutting the wafer into chips. A method for manufacturing a chip made of a brittle material.   The manufacturing method of the chip | tip which consists of a brittle material of Claim 1 with which the convex part which consists of embedding resin is provided in the circumference | surroundings of the said embrittled ingot so that it may become parallel to the longitudinal direction of a brittle ingot.   The method for manufacturing a chip made of a brittle material according to claim 1 or 2, wherein a plurality of rod-shaped brittle ingots are embedded in parallel in the longitudinal direction.   The method for manufacturing a chip made of a brittle material according to claim 3, wherein a part of the embedding resin is removed by cutting.   The manufacturing method of the chip | tip which consists of a brittle material of Claim 3 or 4 with which the opening hole is formed between these brittle ingots.   The brittle material according to any one of claims 1 to 5, further comprising a non-defective product separating step for separating a good brittle tip and a cut piece other than the good brittle tip by a specific gravity difference after the cutting step. The manufacturing method of the chip | tip which becomes.   The method for producing a chip made of a brittle material according to any one of claims 1 to 6, wherein the embedding resin is a porous resin.   The method for producing a chip made of a brittle material according to any one of claims 1 to 6, wherein the embedding resin is a liquid thermosetting resin or a liquid photocurable resin.   The method for manufacturing a chip made of a brittle material according to claim 8, wherein the thermosetting resin or the photocurable resin is an epoxy resin.   The manufacturing method of the chip | tip which consists of a brittle material of any one of Claims 1-9 further equipped with the metallizing process which metallizes the said brittle wafer between the said slicing process and a cutting process.

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