KR20210142584A - Semiconductor device manufacturing method and laminate - Google Patents

Abstract

Provided is a method for manufacturing a semiconductor device in which cracks or defects are less likely to occur in chips during a manufacturing process even when the distance between adjacent chips after segmentation is small. A method for manufacturing a semiconductor device having a rectangular planar shape, wherein an adhesive sheet is attached to a surface of a wafer including a plurality of rectangular region to be divided into pieces arranged in a matrix along a short side direction of the region to be divided into pieces, It is a manufacturing method of a semiconductor device which grinds the back surface of the wafer to which the said adhesive sheet was affixed, and divides the said chip|tip along the division|segmentation predetermined line which defines the said segmentation schedule area|region.

Description

Semiconductor device manufacturing method and laminate

BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and to a laminate used for a method for manufacturing a semiconductor device.

As a manufacturing process of semiconductor devices, such as a semiconductor chip in which the semiconductor circuit was formed on the silicon substrate, the method called DBG (Dicing Before Grinding) is known. DBG is a method of dividing the wafer into individual semiconductor chips by forming a groove having a depth corresponding to the finished thickness in the street of the wafer and grinding the back surface of the wafer to expose the previously formed groove from the back surface of the wafer.

A method called SDBG (Stealth Dicing Before Grinding) has also been proposed for the purpose of increasing the number of chips obtained from one wafer. In SDBG, the light-converging point of a laser having a wavelength that is transparent to the wafer is located inside the wafer, the laser is irradiated to the wafer along a line to be divided, a modified layer by multiphoton absorption is formed inside the wafer, and then the wafer It is a processing method in which the wafer is thinned by grinding the back side of the , and the wafer is divided into individual semiconductor chips using the modified layer as the division starting point.

When a processing method in which the gap between the chips in the divided wafer is very small, like SDBG, is used, defects or cracks may occur in the divided semiconductor chip. For this reason, for example, in patent document 1, it is proposed to form the defect prevention layer which consists of a metal film etc. at each intersection of the division|segmentation schedule line of a wafer surface.

Japanese Laid-Open Patent Publication No. 2018-6653

However, the request|requirement for the miniaturization of a chip size is increasing more and more, and the problem of the crack or defect of a semiconductor chip has become remarkable with miniaturization of a semiconductor chip. According to the studies of the present inventors, when using a method in which the gap formed by dicing in DBG is as small as possible or a method in which the gap between neighboring chips is substantially zero at the time of dividing the wafer like SDBG, the chip size It became clear that the problem of cracks and defects due to contact between adjacent chips became more pronounced when the chip was downsized. Accordingly, there is a demand for a novel and useful method for manufacturing a semiconductor device capable of more effectively preventing chip defects and cracks.

In view of the above problem, the present invention provides a method for manufacturing a semiconductor device in which cracks or defects are less likely to occur in the chip during the manufacturing process even when the distance between adjacent chips after segmentation is small, and a laminate suitable therefor make it a task

MEANS TO SOLVE THE PROBLEM As a result of repeating earnest examination in order to solve the said subject, the present inventors solve the said subject by setting the sticking direction of the adhesive sheet affixed to the circuit layer formation surface of a wafer suitably based on the segmentation scheduled area of a wafer. Finding out what could be done, the present invention was completed.

That is, the present invention provides the following [1] to [6].

[1] A method for manufacturing a semiconductor device having a rectangular planar shape, the method comprising:

A pressure-sensitive adhesive sheet is attached to a surface of a wafer including a plurality of rectangular segmentation scheduled regions arranged in a matrix along a short side direction of the segmented segmentation region,

The manufacturing method of a semiconductor device which grinds the back surface of the wafer to which the said adhesive sheet was affixed, and divides the said wafer along the division|segmentation predetermined line which defines the said segmentation schedule area|region.

[2] After attaching the pressure-sensitive adhesive sheet to the surface of the wafer, a modified portion serving as a starting point of division is formed inside the wafer at a planar position corresponding to the division line,

The method for manufacturing a semiconductor device according to the above [1], wherein the back surface of the wafer to which the pressure-sensitive adhesive sheet is affixed is ground, and the wafer is divided along the division line.

[3] The method for manufacturing a semiconductor device according to [1] or [2], wherein an aspect ratio expressed by the length in the long side direction/the length in the short side direction of the region to be divided into pieces is 1.05 or more.

[4] The method for manufacturing a semiconductor device according to any one of [1] to [3], wherein the region to be divided into pieces has a length of 5 to 50 mm in the long side direction and 2 to 20 mm in the short side direction. .

[5] affixing a transfer sheet to the back surface of the wafer after grinding;

The method for manufacturing a semiconductor device according to any one of [1] to [4], wherein the pressure-sensitive adhesive sheet is separated from the wafer after the transfer sheet is pasted.

[6] A wafer including a plurality of rectangular segmented regions arranged in a matrix;

A laminate comprising an adhesive sheet affixed to the surface of the wafer in a state in which tension is applied along the short side direction of the region to be separated into pieces.

ADVANTAGE OF THE INVENTION According to this invention, even when the distance between adjacent chips after fragmentation is small, in a manufacturing process, the manufacturing method of a semiconductor device which a chip|tip does not easily generate|occur|produce a crack or defect, and a laminated body suitable for it can be provided. .

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing of the semiconductor chip as a semiconductor device obtained by processing the wafer using the wafer with a circuit layer, the laminated body in which the adhesive sheet was affixed on the circuit layer of this wafer, and this laminated body.
It is explanatory drawing which shows the relationship between the sticking direction of the adhesive sheet with respect to a wafer, and the area|region to be separated on a wafer.
3 is a schematic cross-sectional view showing a manufacturing process of a laminate.
4 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device.
5 is a schematic cross-sectional view showing a manufacturing process of a semiconductor device.
Fig. 6 is a schematic plan view showing a wafer used in a method for manufacturing a semiconductor device according to an embodiment of the present invention and a wafer used in a method for manufacturing a semiconductor device according to a comparative example in contrast.

EMBODIMENT OF THE INVENTION Hereinafter, embodiment of this invention (Hereinafter, it may call "this embodiment") is described.

[Wafer, laminate, and semiconductor device]

The semiconductor device manufactured by the semiconductor device manufacturing method of this embodiment is equipped with the wafer part and the circuit part formed in the surface, The planar shape is rectangular shape. In this specification, the term "semiconductor device" refers to the overall device that can function by using semiconductor characteristics used for a processor, a memory, a sensor, and the like. Specifically, a wafer provided with an integrated circuit, a thinned wafer provided with an integrated circuit, a chip provided with an integrated circuit, a thinned chip provided with an integrated circuit, an electronic component comprising these chips, and the said chip Electronic devices provided with an electronic component, etc. are mentioned. Chips before packaging are also included.

A semiconductor device is obtained by separating into pieces the wafer in which the circuit layer was formed on the surface.

Moreover, in the process of processing a wafer with a circuit layer into a semiconductor device, the laminated body which affixed the adhesive sheet on the circuit layer formation surface of the wafer is used.

EMBODIMENT OF THE INVENTION Hereinafter, the wafer, laminated body, and semiconductor device which concern on embodiment of this invention are demonstrated using drawings.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic sectional drawing of the semiconductor chip as a semiconductor device obtained by processing the wafer with a circuit layer, the laminated body by which the adhesive sheet was affixed on the surface on which the circuit layer of this wafer was formed, and the said wafer.

As shown in FIG. 1(A) , first, a wafer W having a circuit layer C formed on its surface is prepared by a semiconductor formation process including a photolithography method.

Next, as shown in FIG.1(B), the adhesive sheet 1 is affixed on the surface in which the circuit layer C of the wafer W was formed, and the laminated body 10 is obtained.

Further, as shown in Fig. 1(C) , the back surface of the wafer W is ground as necessary, and the wafer W is divided along a division scheduled line defining a region to be divided into pieces, Let it be the later wafer WI. In this way, the wafer W which has the circuit layer C is divided into plural pieces, and the semiconductor chip CP as a semiconductor device is obtained. The area to be reorganized will be described in detail later.

<Wafer>

The wafer W is obtained by cutting high-purity single-crystal silicon into a disk shape. Although the diameter of the wafer W is not limited to this, For example, it is 12 inches.

The circuit layer (C) is a layer including a semiconductor circuit formed on the surface of the wafer (W) by a semiconductor manufacturing process.

A semiconductor process includes a process of forming a semiconductor circuit by photolithography after forming a thin film of silicon oxide, aluminum, etc. which become a material of a circuit on a silicon wafer by sputtering, electroplating, CVD, etc.

The photolithography method is a process of coating the thin film formed on a silicon wafer with a resist film, a process of irradiating the resist film with UV light through a mask on which a circuit pattern is formed, a process of developing an uncured portion of the resist film Selective removal process, process of etching and removing the thin film exposed by development, process of imparting semiconductor characteristics by implanting impurities such as phosphorus or boron into the silicon substrate exposed by etching, flash lamp or laser irradiation, etc. It has a process of activating impurity ions by the heat treatment used, and a process of peeling a resist film.

<Semiconductor device>

As an example, the wafer W is divided|segmented so that it may become the size of a planar view so that it may become a some semiconductor chip each with a size of about 12 mm x 6 mm. When dividing by this size, about 1,000 semiconductor chips are obtained from a wafer having a diameter of 12 inches.

As mentioned above, the semiconductor chip which is a semiconductor device is equipped with the wafer part originating in the wafer W, and the circuit part originating in the circuit layer C formed in the surface.

The semiconductor chip obtained by the manufacturing method of the semiconductor device of this embodiment has a rectangular planar shape. For this reason, various functions can be provided to a semiconductor chip, and the top and bottom of a semiconductor chip can be grasped|ascertained easily.

<Laminate>

The laminate 10 is one in which the pressure-sensitive adhesive sheet 1 is affixed on the surface of the wafer W on which the circuit layer C is formed.

(adhesive sheet)

The pressure-sensitive adhesive sheet 1 is a laminate including a base layer and an adhesive layer laminated on the base layer, typically, a base layer, a buffer layer formed on at least one surface side of the base layer, and a base layer It is a laminated body containing the adhesive layer formed in the other surface side. The pressure-sensitive adhesive sheet 1 may include other constituent layers other than these, for example, a primer layer may be formed on the surface of the substrate on the pressure-sensitive adhesive layer side, and on the surface of the pressure-sensitive adhesive layer, to protect the pressure-sensitive adhesive layer until use The release sheet for this purpose may be laminated|stacked. Moreover, a single layer may be sufficient as a base material, and a multilayer may be sufficient as it. The buffer layer and the pressure-sensitive adhesive layer are also the same. When the pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet 1 is in contact with the circuit layer C of the wafer W, and the pressure-sensitive adhesive sheet 1 is attached to the wafer W, the pressure-sensitive adhesive sheet 1 is formed of the wafer W It serves as a protective film for protecting the circuit layer (C).

(substrate layer)

Although the material in particular of a base material layer is not restrict|limited, Compared with paper or a nonwoven fabric, since there is little dust generation, it is preferable for the processing member of an electronic component, It is preferable that it is a resin film from a viewpoint of easy availability. When an adhesive sheet has a base material layer, the shape stability of an adhesive sheet can be improved, or elasticity can be provided to an adhesive sheet. Moreover, even when the unevenness|corrugation of the circuit layer C of the wafer W is large, it becomes easy to keep the surface opposite to the pasting surface of an adhesive sheet smooth.

The base material layer may be a base layer composed of a single layer film composed of one resin film, or a base material layer composed of a multilayer film in which a plurality of resin films are laminated.

The thickness of the base layer is preferably 5 to 250 µm, more preferably 10 to 200 µm, still more preferably from the viewpoint of imparting moderate elasticity to the pressure-sensitive adhesive sheet, and from the viewpoint of handling properties at the time of winding the pressure-sensitive adhesive sheet. It is 25-150 micrometers.

As a resin film that can be used for the base layer, for example, a polyolefin-based film, a halogenated vinyl polymer-based film, an acrylic resin-based film, a rubber-based film, a cellulose-based film, a polyester-based film, a polycarbonate-based film, a polystyrene-based film, The film which consists of a polyphenylene sulfide type film, a cycloolefin polymer type film, and the hardened|cured material of the energy-beam curable composition containing a urethane resin is mentioned.

The polyester film used for the base layer may be a film made of a copolymer of polyester, or a resin mixed film comprising a mixture of the polyester and a relatively small amount of another resin. Among these polyester films, a polyethylene terephthalate film is preferable from a viewpoint that an acquisition is easy and thickness precision is high.

(Adhesive layer)

The pressure-sensitive adhesive layer formed on the base layer or the intermediate layer protects the circuit layer (C) by reliably fixing the pressure-sensitive adhesive sheet to the circuit layer (C) of the wafer (W).

The pressure-sensitive adhesive layer contains a pressure-sensitive adhesive. As an adhesive, an acrylic adhesive, a rubber-type adhesive, a urethane adhesive, a silicone adhesive, a polyvinyl ether type adhesive, an olefin adhesive etc. are mentioned, for example. You may use these adhesives 1 type or in combination of 2 or more type.

Although the thickness of an adhesive layer can be suitably adjusted according to the size of the unevenness|corrugation of the circuit layer used as a protection object, Preferably it is 5-200 micrometers, More preferably, it is 7-150 micrometers, More preferably, it is 10-100 micrometers.

(middle floor)

The intermediate layer is not particularly limited, but is preferably formed of a resin composition containing a urethane (meth)acrylate and a thiol group-containing compound from the viewpoint of obtaining good water absorbency.

The thickness of the intermediate layer can be appropriately adjusted according to the size of the unevenness on the surface of the semiconductor to be protected, but from the viewpoint of making it possible to absorb relatively large unevenness, preferably 50 to 400 µm, more preferably 70 to 300 µm, more preferably 80 to 250 µm.

(Attaching direction of the adhesive sheet)

2 : is explanatory drawing which shows the relationship between the sticking direction of the adhesive sheet 1 with respect to the wafer W, and the area|region R to be separated into pieces on the wafer W. As shown in FIG.

As shown in Fig. 2(A) , on the surface of the wafer W, a V-notch Wv indicating a reference direction for processing or processing on the wafer W, and an individual defined by a division line E A semiconductor circuit formed in the region R to be divided into pieces is formed. The semiconductor circuit is formed on the basis of the direction indicated by the V notch Wv. Moreover, bonding of the adhesive sheet mentioned later is performed on the basis of the direction which V-notch (Wv) shows as a reference.

Here, the area|region R to be divided into pieces is rectangular shape in planar view. The division scheduled line E defining the segmentation scheduled area R is virtual, and individual circuits need only be formed so as not to exceed the division scheduled line E, and the division defining the segmentation scheduled area R It is not necessary to physically form the predetermined line E on the surface of the wafer W or the circuit layer C. However, in order to make it easier to recognize the region R to be divided into pieces or to allow the division of the wafer W to proceed smoothly, even if a processing groove serving as the division line E is formed in advance by a photolithography method, etc. do.

By making the segmentation scheduled area|region R into square shape, the shape of the semiconductor chip finally obtained also becomes a square shape.

In the example shown in FIG.2(A), the short side direction d2 of each segmentation scheduled area|region R may correspond with the direction d3 (henceforth also referred to as a longitudinal direction) indicated by the V-notch Wv. Each circuit of (C) is formed. Thereby, the long side direction d1 of the segmentation scheduled area|region coincides with the direction (hereinafter also referred to as a transverse direction) orthogonal to the direction d3 indicated by the V-notch Wv.

The length in the longitudinal direction of the region R to be divided into pieces is preferably 5 to 50 mm, More preferably, it is 7-40 mm, More preferably, it is 10-30 mm.

The length in the short side direction of the region R to be divided into pieces is preferably 2 to 20 mm, more preferably 3 to 18 mm, from the viewpoint of improving handling ease or making it easy to provide the minimum necessary function to the semiconductor chip. mm, More preferably, it is 4-15 mm.

The aspect ratio expressed by the ratio of the length in the long side direction to the length in the short side direction of the region R to be divided into pieces (long side length/short side direction length) is the ability to suppress defects or cracks in the semiconductor chip during the manufacturing process. , from the viewpoint of appropriately maintaining the balance of function imparting properties to the semiconductor chip, preferably 1.05 or more, more preferably 1.10 or more, still more preferably 1.15 or more, and preferably 10 or less, more preferably It is 7.0 or less, More preferably, it is 5.0 or less.

In addition, in this embodiment, since the wafer W is divided|segmented by SDBG when manufacturing a semiconductor device as mentioned later, the distance between adjacent chips is substantially zero. For this reason, the length of the longitudinal direction and the lateral direction of the segmentation scheduled area|region R correspond to the length of the longitudinal direction and lateral direction of a semiconductor chip.

In addition, the semiconductor circuit may not be formed other than the segmentation scheduled region R, and an unused semiconductor circuit may be formed as a dummy circuit other than the segmentation segmentation area|region R.

As shown in FIG. 2(B) , the pressure-sensitive adhesive sheet 1 has a length and a width that can cover the entire surface of the wafer W. When using the wafer W with a diameter of 12 inches, as the adhesive sheet 1, a long thing with a width of 400 mm can be used, for example. In addition, in FIG.2(B), in order to make understanding easy, the wafer W covered with the adhesive sheet 1 and its segmentation scheduled area|region R are shown with the thin line. When the adhesive sheet 1 uses what has light transmittance, the shape and the alignment direction of the area|region R to be separated into pieces can be confirmed through the adhesive sheet 1 .

When affixing the adhesive sheet 1, the wafer W is set in the bonding apparatus on the basis of the direction d3 which the V-notch Wv shows. At this time, the wafer W is set so that the sticking direction d4 of the adhesive sheet 1 by a sticking apparatus may follow the direction d3 which the V-notch Wv shows. Thereby, in this embodiment, the short side direction d2 of the segmentation scheduled area R follows the direction d3 shown by the V notch Wv.

After the adhesive sheet 1 is affixed on the circuit layer C of the wafer W, the adhesive sheet 1 which protruded from the wafer W is cut|disconnected and removed as needed. As will be described later, when the pressure-sensitive adhesive sheet 1 is pasted by a method of pasting while applying tension so as to eliminate warpage of the pressure-sensitive adhesive sheet 1, tension is applied along the pasting direction d4 of the pressure-sensitive adhesive sheet 1 The pressure-sensitive adhesive sheet 1 is affixed on the circuit layer (C). Thereby, the laminated body 10 is formed in the state to which the tension was added in the direction along the short side direction d2 of the segmentation scheduled area|region R.

Here, the sticking direction d4 of the pressure-sensitive adhesive sheet is set to follow the direction d3 indicated by the V notch Wv (that is, in this example, the short side direction d2 of the region R to be separated into pieces). As shown in 2(B), the sticking direction d4 of the adhesive sheet 1 may be set so that it may become within the fixed angle (theta) with respect to the direction d3 which the V-notch Wv shows. Here, θ is in the range of preferably ±45°, more preferably ±40°, still more preferably ±35° with respect to the direction d3 indicated by the V notch Wv.

[Method for producing a laminate]

3 is a schematic cross-sectional view showing a manufacturing process of a laminate. 3(A) is a diagram showing a state in which a wafer W with a circuit layer C formed thereon is mounted on a support 100, and FIG. 3(B) is a circuit of the wafer W It is a figure which shows the mode that the adhesive sheet 1 is affixed on the layer (C), and FIG. 3(C) shows a mode that the adhesive sheet 1 is affixed on the circuit layer (C) of the wafer (W). It is a drawing.

As shown in Fig. 3(A), after the wafer W is placed on the support body 100 so that the back surface of the wafer W on which the circuit layer C is formed is in contact with the support body 100, Fig. 3(B) ), the adhesive sheet 1 is affixed on the circuit layer C of the wafer W. As shown in FIG. In this example, one end of the pressure-sensitive adhesive sheet 1 is wound with a winding member or gripped by a gripping member to keep the pressure-sensitive adhesive sheet 1 from the other end while floating from the wafer W. ), the pressure-sensitive adhesive sheet 1 is affixed to the surface on which the circuit layer C of the wafer W is formed.

At this time, a certain tension is applied in the longitudinal direction of the pressure-sensitive adhesive sheet 1 (that is, the sticking direction of the pressure-sensitive adhesive sheet 1) in order to eliminate the sagging of the pressure-sensitive adhesive sheet 1 as much as possible, or a pressing force by a pressing body is applied to the pressure-sensitive adhesive. By being added in the longitudinal direction of the sheet 1, the adhesive sheet 1 is affixed to the wafer W in the state to which the tension was applied in the pasting direction d4. In the width direction of the adhesive sheet 1, the adhesive sheet 1 is affixed to the circuit layer C of the wafer W in the state to which almost no tension was applied.

After the adhesive sheet 1 is affixed on the circuit layer C, the adhesive sheet 1 which protruded from the wafer W is cut|disconnected and removed as needed. In this way, as shown in FIG.3(C), the laminated body 10 by which the adhesive sheet 1 was affixed on the circuit layer C of the wafer W is manufactured.

In addition, there is no restriction|limiting in particular in the material which comprises the support body 100, For example, metal materials, such as stainless steel, are used.

[Method for manufacturing semiconductor device]

An example of the manufacturing method of the semiconductor device of the present embodiment is to process a laminate in which an adhesive sheet is affixed on the circuit layer of the wafer, divide the wafer and grind the back surface of the wafer, A step of affixing a transfer sheet to a surface opposite to the circuit layer formation surface (that is, the back surface of the wafer), removing the adhesive sheet, and then dividing the wafer together with the transfer sheet into pieces is included. Hereinafter, each process is demonstrated sequentially. In addition, the transfer sheet is a sheet for holding the wafer by being affixed to the back surface of the wafer and then transferring the wafer to the surface after the wafer is separated from the pressure-sensitive adhesive sheet.

4 and 5 are schematic cross-sectional views showing a manufacturing process of a semiconductor device.

FIG. 4(A) is a diagram showing a state in which the laminate 10 is mounted on a support 200 separate from the support 100 . As shown in FIG.4(A), the laminated body 10 is mounted on the support body 200 so that the adhesive sheet 1 may contact|connect the support body 200. As shown in FIG. In addition, as the support body 200, the thing of the same material as the support body 100 or a ceramic porous table can be used, for example.

Fig. 4B is a diagram showing a state in which a laser is irradiated to the wafer W from the back side. As shown in Fig. 4(B), using the condenser 102, the laser 103 is positioned so that the light-converging point of the laser 103 having a wavelength that is transparent to the wafer W is inside the wafer W. The laser 103 is irradiated onto the wafer W from the back side while relatively moving the laser 103 and the wafer W along the predetermined division line E defining the segmentation scheduled region R. do. Thereby, the modified part M is formed in the inside of the wafer W in the planar position corresponding to the dividing line E. The modified portion M is a portion where the wafer W is modified by laser irradiation, and serves as a starting point at which the wafer W is cut.

FIG. 4(C) is a diagram showing a state in which the back surface side of the wafer W is ground. As shown in FIG. 4(C) , the back surface of the wafer W is ground using the grinder 104 until a desired thickness is obtained. By this process, the wafer W is reduced in thickness and weight. At the same time, starting from the reforming portion M, the wafer W is cut along the planned division line E defining the segmentation scheduled region R. Moreover, the modified part M formed in the wafer W is removed by grinding.

In SDBG, when a wafer is divided during grinding, only cracks due to stealth dicing (symbol P in Fig. 4(C)) exist between neighboring chips, and the distance between the chips is substantially zero. For this reason, the chip is shifted by a slight stress or impact, and it is easy to generate|occur|produce contact, pressurization, friction, collision, or the like between the chips, which is a situation in which cracks are likely to occur. Moreover, when affixing adhesive sheets, such as a protective sheet for back grinds, in order to apply tension in the sticking direction, and to stick, it becomes easy for stress to remain|survive in the laminated body after sticking an adhesive sheet. For this reason, by grinding the back surface of the wafer, the wafer W is split into individual chips starting from the modified portion M, and the stress in the laminate is released, and the chips move easily in the sticking direction of the pressure-sensitive adhesive sheet. As a result, it is presumed that the chips contact, press, rub, or collide to cause cracks.

In the semiconductor device manufacturing method of the present embodiment, the reason for suppressing chip breakage and cracking is not limited to this, but one of the following reasons can be considered. In other words, by making the length in the longitudinal direction of the chip different from the length in the transverse direction and attaching the pressure-sensitive adhesive sheet along the short side direction of the chip, compared to the case where the pressure-sensitive adhesive sheet is pasted along the long side direction of the chip, the sticking direction of the pressure-sensitive adhesive sheet The number of cutting lines between chips in the Thereby, it is estimated that the amount of movement of the chip|tip in the sticking direction is disperse|distributed by more chips|tips, the contact, pressurization, friction, collision, etc. of chip|tips decrease, leading to suppression of a crack and a defect.

In addition, although the modified part is removed by grinding in this embodiment, for example, in applications where thinning of the wafer is not required or when the original thickness of the wafer is thick, at least a part of the modified part remains on the wafer even after grinding. do.

FIG. 5(A) shows a step of separating the stacked body 11 in which the wafer W is ground and divided from the support 200 . FIG. 5(B) shows a step of adhering the laminate 11 in which the wafer W is ground and divided to the transfer sheet held by the ring frame 300 . FIG. 5(C) shows a step of separating the pressure-sensitive adhesive sheet 1 from the laminate 11 affixed to the transfer sheet 303 . FIG. 5D is an expand process for separating individual chips together with the transfer sheet 303 .

As shown in FIG. 5(A), the stacked body 11 in which the wafer W is ground and divided, separated from the support 200, is formed by a ring frame 300 as shown in FIG. 5(B). It is adhered to the film adhesive 301 of the transfer sheet 303 including the film adhesive 301 and the support sheet 302, the periphery being held. And as shown in FIG.5(C), the adhesive sheet 1 is isolate|separated from the laminated body 11 by which the wafer W was ground and divided|segmented, Furthermore, as shown in FIG.5(D), the support sheet By pulling (302), the film adhesive 301 is also cut to fit the chips (the film adhesive after cutting is denoted by reference numeral 301a), leaving a gap G between the chips, and separating them into individual chips.

In addition, as the transfer sheet 303, for example, on a support sheet 302 including a base material made of the same material as the base material layer of the pressure-sensitive adhesive sheet 1 described above, an adhesive layer is interposed if necessary, What is formed with the film-like adhesive 301 which has curability can be used.

According to the above manufacturing method, while suppressing generation|occurrence|production of a chip|chip defect and a crack during a manufacturing process, a semiconductor device can be manufactured with a high yield rate.

In addition, although the wafer is divided|segmented by SDBG in this embodiment, it is not limited to this, For example, you may divide|segment a wafer using DBG. When DBG is used, when the distance between chips formed by dicing is small, the effect of preventing chip breakage and cracking is likely to be exhibited. When DBG is used, after half-cutting a wafer from the front surface of the wafer with a circuit layer, an adhesive sheet is affixed to the circuit formation surface of a wafer, and what is necessary is just to grind the back surface of a wafer after that.

Example

Next, specific examples of the present invention will be described, but the present invention is not limited by these examples at all.

[Examples and Comparative Examples]

The chips of Examples 1-3 and Comparative Examples 1-4 were manufactured in the following procedure. In Examples 1 to 3 and Comparative Examples 1 to 4, all mirror wafers in which no circuit layer was formed were used from the viewpoint of matching the experimental conditions as much as possible and facilitating the experiment.

<Example 1>

A mirror wafer of single crystal silicon having a diameter of 12 inches is prepared, and with the V notch formed in the mirror wafer as a reference, the adhesive sheet is applied to one side of the wafer along the direction indicated by the vertex of the V notch (hereinafter referred to as the longitudinal direction). It affixed on the surface (henceforth a 1st surface). As the adhesive sheet, a back grind tape "E-3135KN" manufactured by Lintec Co., Ltd. was used. The sticking of the adhesive sheet uses a sticking device ("RAD-3510F/12" manufactured by Lintec Co., Ltd.), a press-in amount of 15 µm, a protrusion amount of 150 µm, a sticking speed of 5 mm/s, a sticking stress of 0.35 MPa, and a sticking temperature of 23 It was carried out under the conditions of °C.

Next, SDBG was performed so that the length of the longitudinal direction was set to 6 mm, and the length of the direction orthogonal to the longitudinal direction (hereinafter, referred to as the transverse direction) was 12 mm. Specifically, using a stealth dicing laser saw "DFL7361" manufactured by Disco Co., Ltd., laser irradiation is performed from the surface (hereinafter referred to as the second surface) opposite to the first surface of the wafer, and the length is 6 mm. The modified layer was formed inside the wafer so that the area|region to be segmented into the size of 12 mm x width|variety was formed in a row in 980 matrix form.

Further, using a back surface grinding device ("DPG8760" manufactured by Disco Co., Ltd.), the other side of the wafer (hereinafter referred to as a second surface) is ground until the thickness of the wafer is 30 µm, whereby the inside of the wafer is While the reformed layer was removed, the wafer was cut along the dividing line that defines each segmented region.

Next, the dicing tape ("D-175" manufactured by Lintec Co., Ltd.) installed on a tape mounter "RAD-2700" manufactured by Lintec Co., Ltd. was affixed to the second surface of the separated wafer, and the adhesive sheet was removed. And the presence or absence of crack generation|occurrence|production from the 1st surface side was observed using the IR camera installed in the stealth dicing laser saw, and the number of the chip|tip which a crack generate|occur|produced was counted.

The crack occurred in one chip out of 980, and the crack occurrence rate was 0.10%.

<Example 2>

In the same procedure as in Example 1 along the longitudinal direction, with respect to the wafer to which the pressure-sensitive adhesive sheet was affixed on the first surface, the same procedure as in Example 1, except that the length in the longitudinal direction was 4 mm and the length in the transverse direction was 12 mm. SDBG processing was performed on the wafer under the same conditions, and the wafer was divided into 1471 chips.

As a result of carrying out observation similarly to Example 1, the crack generation rate was 0.07 % as one of 1471 chips in which the crack generate|occur|produced.

<Example 3>

In the same procedure as in Example 1, in the longitudinal direction, with respect to the wafer to which the pressure-sensitive adhesive sheet was affixed on the first surface, the length in the longitudinal direction was 8 mm and the length in the transverse direction was 12 mm. SDBG processing was performed on the wafer under the same conditions, and the wafer was divided into 735 chips.

As a result of carrying out observation similarly to Example 1, the crack occurrence rate was 0.13 % of the chip|tip in which the crack generate|occur|produced as 1 in 735 pieces.

<Comparative Example 1>

In the same procedure as in Example 1, in the longitudinal direction, with respect to the wafer to which the pressure-sensitive adhesive sheet was affixed on the first surface, the length in the longitudinal direction was 12 mm and the length in the transverse direction was set to 6 mm. SDBG processing was performed on the wafer under the same conditions, and the wafer was divided into 980 chips.

Fig. 6 is a schematic plan view showing an example of the present invention and a comparative example in comparison. As shown in Fig. 6(A), in the wafers W1 of Examples 1 and 2, the sticking direction d4 of the pressure-sensitive adhesive sheet 1 and the short-side direction d2 of the region R to be separated into pieces, It coincides with the direction d3 indicated by the V notch Wv. On the other hand, as shown in FIG. 6(B) , in the wafer W2 of Comparative Example 1, the V-notch is the sticking direction d4 of the adhesive sheet and the long side direction d1 of the region R to be separated into pieces. It coincides with the direction (d3) shown.

As a result of carrying out observation similarly to Example 1, the crack generation rate was 1.12 % of the chip|tip which a crack generate|occur|produced as 11 pieces out of 980.

<Comparative Example 2>

In the same manner as in Example 1, with respect to the wafer with the adhesive sheet affixed on the first surface, the wafer was subjected to the same conditions as in Example 1, except that the length in the longitudinal direction was 12 mm and the length in the transverse direction was 4 mm. On the other hand, it was processed by SDBG, and it was divided into pieces so that it might become 1471 chips.

As a result of carrying out observation similarly to Example 1, the crack generation rate was 0.95 % as 14 of the 1471 chips|tips which crack generate|occur|produced.

<Comparative example 3>

In the same manner as in Example 1, with respect to the wafer having the pressure-sensitive adhesive sheet affixed on the first surface, the length in the longitudinal direction was 12 mm and the length in the transverse direction was 12 mm. On the other hand, SDBG processing was performed, and it was divided into pieces so that it might become 490 chips.

As a result of carrying out observation similarly to Example 1, the crack generation|occurrence|production rate was 1.22 % of the chip|tip which crack generate|occur|produced as 6 pieces out of 490.

<Comparative Example 4>

In the same manner as in Example 1, with respect to the wafer having the pressure-sensitive adhesive sheet affixed on the first surface, the length in the longitudinal direction was 12 mm and the length in the transverse direction was 8 mm. On the other hand, it was processed by SDBG, and it was divided into pieces so that it might become 735 chips.

As a result of carrying out observation similarly to Example 1, the crack occurrence rate was 1.22 % of the chip|tip in which the crack generate|occur|produced 9 out of 735 pieces.

Table 1 shows the results of Examples 1-3 and Comparative Examples 1-4.

As is clear from the results in Table 1, in Examples 1 to 3 in which the sticking direction of the pressure-sensitive adhesive sheet and the short side direction of the chip coincide with each other, the number of cracked chips is small, and the crack occurrence rate also shows a very small value. Able to know.

On the other hand, in Comparative Examples 1, 2, and 4 which made the sticking direction of an adhesive sheet and the long side direction of a chip|tip coincide, the number of the chip|tip which a crack generate|occur|produced is increasing. In particular, it can be seen that in Comparative Examples 1 and 2, the value of the crack occurrence rate is increased to 10 times or more, respectively, compared to Examples 1 and 2, and Comparative Example 4 is also increased to close to 10 times as in Example 3.

Also in Comparative Example 3, in which the chip shape was square and the length of one side was equal to the length of the long side of the chips of Examples 1 to 3, the number of cracked chips increased, and the value of the crack occurrence rate was , It can be seen that, compared with Examples 1 and 2, it rises 10 times or more, respectively, and it rises close to 10 times that of Example 3.

Industrial Applicability

In the semiconductor device manufacturing method of the present invention, even if a processing method such as SDBG in which the wafer is divided so that the distance between the chips is very small, chip defects or cracks do not easily occur, and semiconductors used for processors, memories, sensors, etc. It can be preferably applied to the manufacture of a chip. Moreover, the laminated body of this invention can be used suitably for the manufacturing method of the said semiconductor device.

1: adhesive sheet
10: laminate
11: Laminate body in which the wafer part was ground and divided
100, 200: support
101: pressurized body
102: light collector
103: laser
104: grinder
300: ring frame
301: film adhesive
301a: cut film adhesive
302: support sheet
303: transfer sheet
C: circuit layer
CP: semiconductor chip (semiconductor device)
d1 : long side direction
d2: short side direction
d3 : direction indicated by the V notch
d4: sticking direction (tension direction)
E: Scheduled division line
G: Gap
M: reformed part
P: crack
R: Area to be reorganized
Wv: V notch
W: Wafer
WI : Segmented wafer

Claims (6)

A method for manufacturing a semiconductor device having a rectangular planar shape, the method comprising:
A pressure-sensitive adhesive sheet is attached to the surface of a wafer including a plurality of rectangular segmentation scheduled regions arranged in a matrix along the short side direction of the segmented segmentation region;
The manufacturing method of the semiconductor device which grinds the back surface of the wafer to which the said adhesive sheet was affixed, and divides the said wafer along the division|segmentation predetermined line which defines the said segmentation schedule area|region. The method of claim 1,
After attaching the pressure-sensitive adhesive sheet to the surface of the wafer, a modified portion serving as a starting point of division is formed in the inside of the wafer at a planar position corresponding to the division line,
The manufacturing method of the semiconductor device which grinds the back surface of the said wafer to which the said adhesive sheet was affixed, and divides the said wafer along the said division|segmentation line. 3. The method according to claim 1 or 2,
The method for manufacturing a semiconductor device, wherein an aspect ratio expressed as a length in a long side direction/length in a short side direction of the region to be divided into pieces is 1.05 or more. 4. The method according to any one of claims 1 to 3,
The method of manufacturing a semiconductor device, wherein the segmented region has a length of 5 to 50 mm in a long side direction and 2 to 20 mm in a short side direction. 5. The method according to any one of claims 1 to 4,
A transfer sheet is affixed to the back surface of the wafer after grinding,
A method for manufacturing a semiconductor device, wherein the pressure-sensitive adhesive sheet is separated from the wafer after the transfer sheet is pasted. A wafer comprising a plurality of rectangular segmentation scheduled regions arranged in a matrix;
A laminate comprising an adhesive sheet affixed to the surface of the wafer in a state in which tension is applied along the short side direction of the region to be separated into pieces.

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