JP2002118055A - Alignment mark and semiconductor device and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an alignment mark that can achieve desired accuracy in alignment, and the manufacturing of a semiconductor device using the alignment mark. SOLUTION: A through-hole 26 passes extending from a first surface 23, where an element 25 of a substrate 22 in a semiconductor device 21 is formed, to a second surface 24 that is the back surface of the first surface 23. The through-hole 26 is filled with benzocyclobutene as resin 27, and the resin 27 projects from the second surface 24, thus using the through-hole 26 exposed onto the second surface 24 as an alignment mark 28, facilitating carrying out the alignment with naked eyes, and at the same time, improving the alignment accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, wherein a pattern is formed on a second surface, which is a back surface of the first surface, in accordance with a pattern formed on a first surface of a substrate of the semiconductor device. The present invention relates to an alignment mark used in some cases, a semiconductor device using the alignment mark, and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 14A shows a conventional semiconductor device 1 disclosed in Japanese Patent Application Laid-Open No. 6-244073.
FIG. 14B is a cross-sectional view of FIG. In this prior art, a substrate 3 fixed to a support substrate 2
A hole 7 is formed by dry etching from the first surface 5 forming the element 4 to the second surface 6 which is the back surface of the first surface 5. Thereafter, the second surface 6 of the substrate 3 is polished to expose the holes 7 on the second surface 6 of the substrate 3. When a pattern is formed on the second surface 6 of the substrate 3, the holes 7 exposed on the second surface 6 are used as alignment marks. This eliminates the need for a double-sided aligner for simultaneously observing the first surface 5 and the second surface 6 of the substrate 3 and simplifies the manufacturing process of the semiconductor device.

[0003]

However, such a conventional technique has the following problems.

FIG. 15A is a plan view showing a semiconductor device 1A in a case where a hole 7A is formed by wet etching in the above-described prior art, and FIG.
Is a sectional view of the same. The wet etching is simpler than the dry etching and can be easily performed. However, since the etching proceeds according to the crystal orientation of the substrate 3 where the holes 7A are formed as shown in FIG. Has a tapered shape that contracts from the first surface 5 to the second surface 6 of the substrate 3, and the thickness of the substrate 3 becomes extremely thin in a portion where the hole 7 </ b> A is exposed on the second surface 6 of the substrate 3. Would. Such a phenomenon occurs when the substrate 3 is made of GaAs,
It is remarkably found in compound semiconductors such as InP, SiC, GaN, ZnSe, and MoS. The periphery of the portion of the hole 7A exposed on the second surface 6 has become brittle due to the polishing of the substrate 3, and during polishing, the hole 7A has a thickness of about several μm to several tens μm.
Since the size of the portion exposed on the second surface 6 of A changes,
When this hole 7A is used as an alignment mark,
The desired alignment accuracy cannot be obtained.

Further, at the portion where the hole 7A is exposed on the second surface 6 of the substrate 3, the thickness of the substrate 3 becomes extremely thin, and
As shown in the semiconductor device 1B shown in FIG.
A part of the periphery of the exposed portion is partially missing, and the center L1 of the original alignment mark is different from the center L2 of the hole 7B, so that desired alignment accuracy cannot be obtained.

In addition, the following problems occur regardless of the method of forming a hole used as an alignment mark by wet etching and dry etching.

When the substrate 3 is polished and the holes 7 are exposed on the second surface 6 of the substrate 3, the abrasive, lubricating oil and chemicals used for polishing enter the holes 7 and are as shown in FIG. Contaminated sites 8 are created around holes 7 in substrate 3.

In order to fix the first surface 5 of the substrate 3 to the support substrate 2, an adhesive sheet 9 such as an ultraviolet release sheet and a heat release sheet is used. An etching chemical used for etching the substrate 3 and an organic solvent for cleaning the resist used for stripping the resist after the formation of the pattern on the second surface 6 enter the holes 7 to form the holes 7 as shown in FIG.
The adhesive sheet 9 around the opening on the first surface 5 side is chemically changed by the etching solution and the organic solvent to form a portion 10 that changes the adhesive strength of the adhesive sheet 9. The part 10 makes it difficult to peel the substrate 3 from the adhesive sheet 9.

FIG. 18A is a plan view showing the substrate 3 of the semiconductor device 1 with the resist 11 applied to the second surface 6, and FIG. 18B is a cross-sectional view thereof. At this time,
The resist 11 a, which is a part of the resist 11, enters the hole 7. The resist 11a that has entered the hole 7 is non-uniform in the hole 7, and when the resist 11 is viewed from above, the periphery of the resist 11a becomes an interference pattern, and the alignment mark using the hole 7 and the alignment mark The boundary around is blurred. For this reason, the center L3 of the original alignment mark is different from the center L4 of the alignment mark seen through the resist 11a, and a desired alignment accuracy cannot be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an alignment mark capable of achieving a desired alignment accuracy, a semiconductor device using the alignment mark, and a method of manufacturing the same.

[0011]

SUMMARY OF THE INVENTION The present invention relates to a first substrate.
In an alignment mark provided in a semiconductor device in which an element is formed on a surface and a second surface which is a back surface of the first surface, a through hole penetrating from the first surface to the second surface is provided so as to be exposed from the second surface. An alignment mark characterized by being filled with a filler from a first surface.

According to the present invention, the periphery of the portion of the second surface of the substrate where the through hole is exposed is protected by the filler, and the periphery of the portion is chipped when the second surface of the substrate is polished. And the shape of the alignment mark due to the exposed portion of the second surface of the through hole can be prevented from being changed. Further, since the through holes are filled, it is possible to prevent abrasives, lubricating oil and chemicals from entering the through holes when polishing, and the peripheral portion of the through holes of the substrate is contaminated by these invading substances. Can be prevented. Since the through-hole is filled, it is possible to prevent the etching chemical and the organic solvent for resist cleaning from entering the through-hole when etching the second surface or removing the resist. It is possible to prevent the adhesive sheet fixing the surface and the supporting substrate from being chemically changed by the chemical solution and the solvent, thereby changing the adhesive force and making it difficult to peel the substrate and the supporting substrate.

Further, the present invention is characterized in that the filler is transparent to visible light used for observation of alignment.

According to the present invention, since the filler is transparent to visible light, the outline of the through-hole exposed on the second surface of the substrate can be clearly observed when alignment is performed with the naked eye. And the through hole can be used as an alignment mark.

Further, the present invention is characterized in that the filling material has a different light absorptivity than a resist material applied thereon.

According to the present invention, since the light absorptivity of the resist material and that of the filling material are different from each other, when automatic alignment is performed by, for example, image processing and observation by reflection of a laser beam, the through-hole exposed on the second surface of the substrate is used. The outline of the hole can be clearly observed, and the through hole can be used as an alignment mark.

Further, according to the present invention, the filling material may be a second material of the substrate.
It is characterized by protruding from the surface.

According to the present invention, since the filler protrudes from the second surface of the substrate to form a step, the outline of the filler, that is, the outline of the through hole exposed on the second surface of the substrate is clearly observed. Therefore, the through hole can be used as an alignment mark.

Further, the present invention is characterized in that the filling is made of benzocyclobutene.

According to the present invention, benzocyclobutene is transparent under visible light and has a high degree of pore filling.
The alignment with the naked eye can be easily performed, and the substrate can be protected.

According to the present invention, there is provided a semiconductor device comprising: a first surface of a substrate;
In a method of manufacturing a semiconductor device in which an element pattern is formed on a second surface, which is a back surface of a surface, a through-hole forming step of forming a through-hole penetrating from the first surface to the second surface;
A filling step of filling a filling material from the first surface so as to be exposed from the second surface to form an alignment mark; and using the alignment mark, a filling process for an element pattern formed on the first surface of the substrate. A method of manufacturing a semiconductor device, comprising: an alignment step of aligning an element pattern formed on two surfaces; and an element forming step of forming an element pattern on a second surface.

According to the present invention, highly accurate alignment can be performed. Further, the present invention provides a semiconductor device in which an element is formed on a first surface of a substrate and a second surface which is a back surface of the first surface, wherein a through hole penetrating from the first surface to the second surface is provided. A semiconductor device having an alignment mark that is filled with a filler from a first surface so as to be exposed.

According to the present invention, the periphery of the portion of the second surface of the substrate where the through hole is exposed is protected by the filler, and the periphery of the portion is chipped when the second surface of the substrate is polished. And the shape of the alignment mark due to the exposed portion of the second surface of the through hole can be prevented from being changed. Further, since the through holes are filled, it is possible to prevent abrasives, lubricating oil and chemicals from entering the through holes when polishing, and the peripheral portion of the through holes of the substrate is contaminated by these invading substances. Can be prevented. Since the through-hole is filled, it is possible to prevent the etching chemical and the organic solvent for resist cleaning from entering the through-hole when etching the second surface or removing the resist. It is possible to prevent the adhesive sheet fixing the surface and the supporting substrate from being chemically changed by the chemical solution and the solvent, thereby changing the adhesive force and making it difficult to peel the substrate and the supporting substrate.

[0024]

FIG. 1 is a plan view of a semiconductor device 21 according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along line II-II in FIG. On a first surface 23 of a disk-shaped substrate 22, rectangular elements 25 are arranged in a matrix. The substrate 22 has a cross-shaped through-hole 26 extending from the first surface 23 to the second surface 24 which is the back surface of the first surface 23. On the first surface 23 of the substrate 22,
Resin 27 is applied. The resin 27 fills the through hole 26, is exposed on the second surface 24, and projects from the second surface 24. Thereby, the through-hole 2 exposed on the second surface 24 is formed.
Reference numeral 6 denotes a cross-shaped alignment mark 28. Resin 27
Covers a part of the element 25. The element 25 exposed from the resin 27 has a first electrode part 29 for extracting an electric signal by wire bonding or the like outside the semiconductor device 21. A groove-shaped scribe line 30 serving as a reference for scribing is formed around the element 25 of the resin 27. The resin 27 where the scribe lines 30 are formed is thinly finished.

In this embodiment, the substrate 22 is made of GaAs.
An s substrate is used. The resin 27 is benzocyclobutene (hereinafter, the resin 27 may be referred to as benzocyclobutene 27). Benzocyclobutene is recognized by the naked eye as transparent under visible light, and has a high degree of filling in pores. When the alignment mark 28 filled with benzocyclobutene 27 is viewed from the second surface 24 of the substrate 22, the alignment mark 28 not only looks raised but also transparent than the second surface 24 of the substrate 22. Can be clearly observed. Further, in the present embodiment, since the alignment mark 28 has a cross shape, alignment can be performed with higher accuracy.

A method for manufacturing the semiconductor device 21 according to the present invention will be described. FIG. 3 is a process cross-sectional view showing the first half of the through-hole forming process in the manufacture of the semiconductor device 21. First, the substrate 22
A photoresist 31 is applied to the first surface 23 of the substrate 22 where the elements 25 are to be disposed before the thickness of the substrate 31 is reduced. As the photoresist 31, a novolak positive resist is used. Thereafter, the photoresist 31 is irradiated with ultraviolet light through a glass mask on which the circuit pattern is baked,
A resist pattern is formed by washing the exposed portion of the photoresist 31 with a solvent and leaving the unexposed portion of the photoresist 31.

After hardening the resist pattern,
Etching is performed using the resist pattern as a mask. As the etching solution, a mixed solution of phosphoric acid, hydrogen peroxide, and water, a mixed solution of hydrochloric acid, hydrogen peroxide, and water, or a mixed solution of sulfuric acid, hydrogen peroxide, and water is used. The first surface 2 of the substrate 22 is wet-etched.
3, a hole 26a having a bottom is formed. Hole 26
a is a depth d from the first surface 23 to the bottom of the hole 26a;
It is formed so that d = 20 to 50 μm. Hole 26a
Is made larger than the target thickness when the substrate 22 is made thinner. In the present embodiment, d = 50 μ
m. In this way, a hole 26a that becomes the through hole 26 when the substrate 22 is thinned is formed.

As another method of forming the holes 26a, 1000 to 40 holes are formed between the resist pattern and the substrate 22.
The insulating film is dry-etched using hydrofluoric acid or a chlorofluorocarbon-based gas using the resist pattern as a mask with an insulating film such as a SiN film and a SiO film having a thickness of 00 mm interposed therebetween to form a pattern of the insulating film. There is a method of forming a hole 26a in the substrate 22 using the above-described etching solution as a mask.

There is a method of etching the substrate 22 by dry etching using chlorine gas. In this case, the transfer accuracy of the pattern is much higher than that of wet etching, and the transfer of a pattern having a size of about several μm is possible.

FIG. 4 shows the resin 27 as a filler in the hole 26a.
It is a process sectional view showing the filling process of filling. Substrate 22
After the photoresist 31 on the first surface 23 is removed by ashing treatment using oxygen plasma or the like, the substrate 2 is removed.
2 is coated with a mesitylene solution containing 45% of benzocyclobutene by spin coating.
The rotation speed of the substrate 22 is 2000 rpm, and the application time is 1 minute. Thereafter, the substrate 22 is placed in a nitrogen atmosphere at 90 ° C. for 30 minutes.
Min, followed by 10 minutes at 150 ° C, followed by 10 minutes at 250 ° C.
Heat treatment at 300 ° C. for 10 minutes. By the heat treatment, the benzocyclobutene 27 hardens and fills the holes 26a. At this time, the thickness of the benzocyclobutene 27 on the first surface 23 was 4 to 5 μm in a flat portion. If necessary, the application of benzocyclobutene and the heat treatment may be repeated. When benzocyclobutene was applied under the same conditions as described above, the thickness of the benzocyclobutene 27 on the first surface 23 was about 9 to 10 μm in a flat portion. The amount of the benzocyclobutene 27 filled in the hole 26a is hardly changed by one application of benzocyclobutene or a plurality of applications.

A photoresist is applied on the benzocyclobutene 27 of the substrate 22 on which the benzocyclobutene 27 has been applied, and the first element 25 of the element 25 is subjected to reactive ion etching using a mixed gas of SF ₆ and oxygen. An opening pattern of the electrode section 29 and a pattern of the scribe line 30 are formed. Etching conditions are 150W, pressure 5P
In a, the etching is performed by adjusting the time. The time required for the etching was about 10 minutes.

The thickness of the benzocyclobutene layer 27 at the scribe line 30 is 0.5 μm or more and 10 μm or less. If the thickness of the benzocyclobutene layer 27 at the scribe line 30 is 10 μm or more, the dicing saw blade will be damaged when dicing along the scribe line 30.
When the thickness is 5 μm or more, when the substrate 22 is a compound semiconductor, the benzocyclobutene 27 can prevent chipping that occurs at the edge of the chip when dicing the substrate 22, and can be easily damaged when handling a thin chip. The edge of the chip can be protected. As described above, the semiconductor device 21a which is the semiconductor device 21 before the substrate 22 is thinned is formed.

FIG. 5 is a process sectional view showing the latter half of the through hole forming process in the manufacture of the semiconductor device 21. Substrate 22
The benzocyclobutene 27 formed on the first surface 23 is adhered to the support substrate 33 by the adhesive sheet 32, and the semiconductor device 21a is fixed to the support substrate 33. Support substrate 33
For example, a silicon substrate, a glass substrate, a sapphire substrate, or the like is used.
No. 3 uses a silicon substrate having excellent surface flatness.

As the pressure-sensitive adhesive sheet 32, a normal pressure-sensitive adhesive sheet, a heat-peelable sheet capable of peeling the pressure-sensitive adhesive portion by heating, an ultraviolet-ray peeling sheet capable of peeling the pressure-sensitive adhesive portion by irradiation of ultraviolet rays, and the like are used. The ultraviolet release sheet requires that the supporting substrate be a transparent glass substrate, and also requires an ultraviolet irradiation device. The heat-peelable sheet is preferable because it can be peeled off by heating. In addition, some ordinary pressure-sensitive adhesive sheets have a reduced pressure-sensitive adhesive strength when heated, and such pressure-sensitive adhesive sheets can also be used. These adhesive sheets are
It may be appropriately selected according to the process.

The second surface 24 of the substrate 22 is polished by a lapping device so that the substrate 22 has a desired thickness. As a target of the present embodiment, this thickness was set to 40 μm.
As the polishing proceeds, the second surface 2 of the substrate 22 as shown in FIG.
Benzocyclobutene 27 filled in hole 26a
Is exposed. At this time, benzocyclobutene 27 is
It does not project from the surface 24 and is flush with the second surface 24. After that, the second surface 24 of the substrate 22 is subjected to wet etching using the above-mentioned etching solution, and
About thin. By this etching, as shown in FIG. 6, the benzocyclobutene 27 protrudes from the second surface 24, and an alignment mark 28 is formed.

The above-mentioned pressure-sensitive adhesive sheet, thermal release sheet and ultraviolet release sheet all use an adhesive for fixing the substrate, and the chemicals used when polishing the substrate adhere to the adhesive. In some cases, the adhesive undergoes a chemical change and undergoes a change in quality, so that the adhesive loses its property of being peelable by heat or ultraviolet rays, and may not be peeled off.

On the other hand, in the present invention, by filling the resin (benzocyclobutene) 27 as a filler into the through-hole 26, a chemical used for polishing and an etching solution used for etching enter the through-hole 26. Can be prevented. Thereby, it is possible to prevent the property of the adhesive from being lost so that the adhesive cannot be peeled off, and also prevent the inner peripheral surface of the through hole 26 from being contaminated.

A method of using the alignment mark 28 according to the present invention will be described. In the present embodiment, a via hole is formed in the substrate 22 of the semiconductor device 21. 7 to 9 show the second surface 2 of the substrate 22 of the semiconductor device 21.
FIG. 4 is a process cross-sectional view showing an element forming step of forming a pattern of a semiconductor element in FIG. A photoresist 34 is applied to the second surface 24 of the semiconductor device 21. Alignment mark 28
After the alignment step of aligning the via hole pattern 36 formed in the mask 35 with reference to the above, the via hole pattern 36 is transferred to the photoresist 34 by irradiating light, and the exposed portion of the photoresist 34 is exposed to a solvent. Dissolve the photoresist 3 as shown in FIG.
The pattern 37 is formed on No.4.

The substrate 22 is etched using the photoresist 34 as a mask. As a result, a via hole 38 penetrating from the second surface 24 to the first surface 23 is formed in the substrate 22 as shown in FIG. At this time, the surface on the second surface 24 side of the element 25 is exposed to the via hole 38. The element 25 exposed in the via hole 38 is used for extracting an electric signal outside the semiconductor device 21 by wire bonding or the like.
It becomes the electrode part 39. By measuring the deviation between the center of the via hole 38 and the center of the second electrode portion 39, the deviation of the alignment can be determined. Thereafter, the photoresist 34 is removed, and the substrate 22 as shown in FIG.
A circuit pattern is formed on the second surface 24 of FIG.

According to the present embodiment, alignment mark 28 is formed in through-hole 2 filled with benzocyclobutene 27.
6, and the benzocyclobutene 27 protrudes from the second surface 24 of the substrate 22, so that the outline of the alignment mark 28 can be clearly observed when visually observed.

FIGS. 10 to 12 are cross-sectional views showing the steps of manufacturing a semiconductor device 21A according to another embodiment of the present invention. The semiconductor device 21A is manufactured in the same manner as the semiconductor device 21. In the semiconductor device 21A, the filling resin 27A uses a novolak resist from which a dye component has been removed, and the through holes 26 exposed on the second surface 24 of the substrate 22 filled with the novolak resist serve as alignment marks 28A. The novolak resist is a resin containing a dye. When such a resin is used as the filler, not only the outline of the through-hole 26 exposed on the second surface 24 of the substrate 22 becomes unclear, but also the second surface 24 of the substrate 22 becomes unclear.
Is coated with a novolak-based photoresist, and the second surface 24 is coated.
When the alignment for forming a desired pattern is performed with reference to the through hole 26 exposed to the through hole 26, the through hole 26 exposed to the second surface 24 through the applied photoresist.
Therefore, the outline of the through hole 26 becomes unclear and observation becomes difficult. By removing the dye component of the novolak resist, the light absorption characteristics of the novolak resist are significantly different from the resist applied on the novolak resist, so that the boundary of the alignment mark 28A becomes clear and the alignment accuracy can be improved. It is possible.

A hole 26a is formed from the first surface 23 having the element 25 of the substrate 22 in the same manner as in the semiconductor device 21. In the present embodiment, the resin 27 as a filler is used.
10A, as shown in FIG. 10, etching is performed so as to leave only the periphery of the hole 26a on the first surface 23 of the substrate 22, and the resin 27A is fixed by hard baking. The first surface 23 including the element 25 and the resin 27A adheres to the support substrate 33 with the adhesive sheet 32, and the semiconductor device 21A is fixed to the support substrate 33. Then, the second surface 24 of the substrate 22
Is polished and etched to make the substrate 22 thinner,
As shown in FIG. 11, resin 27 </ b> A, which is a filler, protrudes from second surface 24. Next, as shown in FIG. 12, a photoresist 34 is applied to the second surface 24 of the semiconductor device 21A,
A pattern is formed based on the alignment mark 28A.

FIG. 13 is a graph showing a variation in alignment error between the case where the alignment mark according to the embodiment of the present invention is used and the case where the alignment mark of the prior art is used. In FIG. 13, black circles indicate alignment errors when using the conventional alignment marks, and white circles indicate alignment errors when using benzocyclobutene alignment marks in the embodiment of the present invention.
Black square marks indicate alignment errors when using the novolak resist alignment mark from which the dye component has been removed in the embodiment of the present invention, and white square marks indicate the same light absorption characteristics as the photoresist in the embodiment of the present invention. The following shows an alignment error when a mark having the mark is used as an alignment mark. Ten substrates each having an alignment mark formed by each method were prepared, a photoresist was applied to each substrate, alignment was performed, a pattern was formed, and a via hole was formed in the substrate based on the pattern. At this time, the value of misalignment between the center of the via hole and the center of the electrode portion of the element was measured and compared. The vertical axis in FIG. 13 represents the average value of the alignment error of each substrate. It can be said that the smaller the variation among the substrates is, the easier the alignment mark is to see and the easier the alignment is.

Referring to FIG. 13, when the alignment mark according to the embodiment of the present invention is used, there is less variation in alignment error as compared with the prior art. When benzocyclobutene is used for the alignment mark, the variation can be further suppressed.

In the present embodiment, the number of alignment marks is two on the substrate, but may be one, and by providing two or three at appropriate intervals on the substrate,
Further, alignment can be performed with higher accuracy.

[0046]

As described above, according to the present invention, the periphery of the portion of the second surface of the substrate where the through hole is exposed is protected by the filler, and when polishing the second surface of the substrate, The periphery of the portion can be prevented from being chipped, and the shape of the alignment mark can be prevented from being changed due to the exposed portion of the second surface of the through hole. Further, since the through holes are filled, it is possible to prevent abrasives, lubricating oil and chemicals from entering the through holes when polishing, and the peripheral portion of the through holes of the substrate is contaminated by these invading substances. Can be prevented. Since the through holes are filled, when etching the second surface or removing the resist,
The etching solution and the organic solvent for resist cleaning can be prevented from entering the through hole, and the adhesive sheet for fixing the first surface of the substrate and the supporting substrate is chemically changed by the solution and the solvent, so that the adhesive strength is changed. Thus, it is possible to prevent the separation of the substrate and the supporting substrate from becoming difficult.

According to the present invention, since the filler is transparent to visible light, the outline of the through hole exposed on the second surface of the substrate is clearly observed when alignment is performed with the naked eye. And the through hole can be used as an alignment mark.

According to the present invention, since the light absorption of the resist material differs from that of the filling material, the resist material is exposed to the second surface of the substrate when performing automatic alignment by image processing and observation by reflection of laser light. The outline of the through hole can be clearly observed, and the through hole can be used as an alignment mark.

Further, according to the present invention, the filler is formed on the second substrate.
Since it protrudes from the surface and forms a step, the contour of the filling,
That is, since the outline of the through hole exposed on the second surface of the substrate can be clearly observed, the through hole can be used as an alignment mark.

Further, according to the present invention, since benzocyclobutene is transparent under visible light and has a high degree of filling of holes, alignment with the naked eye can be easily performed and the substrate can be protected. Can be.

According to the present invention, highly accurate alignment can be performed. According to the present invention, the periphery of the portion where the through-hole is exposed on the second surface of the substrate is protected by the filler, and the periphery of the portion is prevented from being chipped when the second surface of the substrate is polished. Can be through-hole second
It is possible to prevent the shape of the alignment mark from being changed due to the exposed portion of the surface. Further, since the through holes are filled, it is possible to prevent abrasives, lubricating oil and chemicals from entering the through holes when polishing, and the peripheral portion of the through holes of the substrate is contaminated by these invading substances. Can be prevented. Since the through holes are filled, the second
When etching the surface or removing the resist, it is possible to prevent the etching solution and the organic solvent for cleaning the resist from entering the through holes, and the adhesive sheet for fixing the first surface of the substrate and the supporting substrate is formed. It is possible to prevent a situation in which it becomes difficult to peel off the substrate and the supporting substrate due to a chemical change due to the chemical solution and the solvent and a change in adhesive force.

[Brief description of the drawings]

FIG. 1 is a plan view of a semiconductor device 21 according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

3 is a process cross-sectional view showing a first half of a through-hole forming process in manufacturing the semiconductor device 21. FIG.

FIG. 4 is a process cross-sectional view showing a filling step of filling a resin 27 as a filler into a hole 26a.

FIG. 5 is a process sectional view showing the latter half of the through-hole forming process in the manufacture of the semiconductor device 21;

FIG. 6 is a cross-sectional view when an alignment mark is formed on the semiconductor device 21;

FIG. 7 is a process cross-sectional view showing an element forming step of forming a pattern of a semiconductor element on a second surface 24 of a substrate 22 of the semiconductor device 21.

8 is a process cross-sectional view showing an element forming step of forming a semiconductor element pattern on a second surface 24 of a substrate 22 of the semiconductor device 21. FIG.

FIG. 9 is a process cross-sectional view showing an element forming step of forming a pattern of a semiconductor element on a second surface 24 of a substrate 22 of the semiconductor device 21.

FIG. 10 shows a semiconductor device 2 according to another embodiment of the present invention.
It is process sectional drawing which shows the manufacturing process of 1A.

FIG. 11 shows a semiconductor device 2 according to another embodiment of the present invention.
It is process sectional drawing which shows the manufacturing process of 1A.

FIG. 12 shows a semiconductor device 2 according to another embodiment of the present invention.
It is process sectional drawing which shows the manufacturing process of 1A.

FIG. 13 is a graph showing a variation in alignment error between the case where the alignment mark according to the embodiment of the present invention is used and the case where the alignment mark of the related art is used.

14A and 14B are a plan view and a cross-sectional view illustrating a semiconductor device 1 according to the related art.

FIG. 15 is a plan view and a cross-sectional view showing a semiconductor device 1A in which a hole 7 is formed by wet etching.

16A and 16B are a plan view and a cross-sectional view illustrating a semiconductor device 1B.

17A and 17B are a plan view and a cross-sectional view illustrating the semiconductor device 1 in which a contaminated portion 8 and a portion 10 that changes the adhesive strength of the adhesive sheet 9 are formed.

FIGS. 18A and 18B are a plan view and a cross-sectional view illustrating a state where a resist is applied to the second surface 6 of the substrate 3 of the semiconductor device 1. FIGS.

[Explanation of symbols]

 21, 21A Semiconductor device 22 Substrate 23 First surface 24 Second surface 25 Element 26 Through hole 27 Resin 28 Alignment mark

Claims (7)

[Claims] An alignment mark provided in a semiconductor device in which an element is formed on a first surface of a substrate and a second surface which is a back surface of the first surface, wherein a through hole penetrating from the first surface to the second surface is provided. A filling material filled from the first surface so as to be exposed from the second surface. 2. The alignment mark according to claim 1, wherein the filler is transparent to visible light used for observation of alignment. 3. The alignment mark according to claim 1, wherein the filler has a different light absorption rate than a resist material applied thereon. 4. The alignment mark according to claim 1, wherein the filler protrudes from the second surface of the substrate. 5. The alignment mark according to claim 1, wherein the filler is made of benzocyclobutene. 6. A method of manufacturing a semiconductor device in which an element pattern is formed on a first surface of a substrate and a second surface which is a back surface of the first surface, wherein a through hole penetrating from the first surface to the second surface is formed. A filling step of filling the through hole with a filler from a first surface so as to be exposed from a second surface to form an alignment mark; and a first surface of a substrate using the alignment mark. A semiconductor device comprising: an alignment step of aligning an element pattern formed on a second surface with an element pattern formed on a second surface; and an element forming step of forming an element pattern on the second surface. Device manufacturing method. 7. A semiconductor device in which elements are formed on a first surface of a substrate and a second surface which is a back surface of the first surface, wherein a through-hole penetrating from the first surface to the second surface is provided. A semiconductor device having an alignment mark that is filled with a filler from a first surface so as to be exposed.