JP2013041965A - Semiconductor device manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent degradation of a dicing blade and prevent an occurrence of chipping to enable manufacturing of a high quality semiconductor device.SOLUTION: A semiconductor device manufacturing method comprises: a filler-containing resin layer formation process S2 of forming a resin layer 14 containing a filler on one surface of a semiconductor wafer W0; and a dicing process S3 of collectively cutting the semiconductor wafer and the resin layer using a dicing blade to singulate the semiconductor wafer.

Description

  The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a technique suitable for use in dicing a device having a resin layer formed on a silicon wafer surface.

In a semiconductor wafer that has been processed at a wafer level, such as a wafer level chip size package (WLCSP), there is a protective resin layer for protecting devices formed on the semiconductor wafer and wiring formed by the package processing. Is formed.
In WLCSP, a protective resin layer is formed and then separated into pieces using a dicing blade attached to a dicing saw.
When dicing to separate a semiconductor wafer into individual semiconductor chips, a cutting blade of the dicing blade cuts a line located between devices called dicing lines formed on the semiconductor wafer.

  Recently, as shown in Patent Document 1, when a semiconductor wafer is diced, the semiconductor wafer main body and the protective resin layer are sometimes collectively cut using a dicing blade.

JP 2011-91453 A

  However, when a semiconductor wafer such as silicon is cut, the dicing blade deteriorates as the dicing is continued, and the cutting ability decreases. Then, chipping of silicon called chipping is likely to occur, and it becomes difficult to manufacture a high-quality semiconductor device.

  Further, when cutting a wafer bonded with glass, it cannot be cut with a silicon wafer cutting blade, so a special blade called a resin blade is required. Since this resin blade is thicker than a silicon blade, chipping is also greatly generated. Therefore, the influence on the deterioration of the quality of the semiconductor device is considerably large, and there has been a demand for improvement.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to reduce the occurrence of chipping by suppressing deterioration of a dicing blade during dicing so that a high-quality semiconductor device can be manufactured. It is.

A manufacturing method of a semiconductor device according to claim 1 of the present invention includes a filler-containing resin layer forming step of forming a resin layer containing a filler on one surface of a semiconductor wafer;
A dicing step of cutting the semiconductor wafer and the resin layer together using a dicing blade to separate the semiconductor wafer;
It is characterized by having.
According to a second aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to the first aspect, wherein an average particle size of the filler is set smaller than an average particle size of abrasive grains included in the dicing blade. .
According to a third aspect of the present invention, there is provided a method for manufacturing a semiconductor device according to the first or second aspect, wherein the filler has a Mohs hardness of 3 or more and 8 or less.
A method of manufacturing a semiconductor device according to a fourth aspect of the present invention is the method for manufacturing a semiconductor device according to any one of the first to third aspects, wherein a glass substrate is bonded to the other surface side of the semiconductor wafer, and the glass substrate is also collectively subjected to the dicing step. It is characterized by cutting.

  According to the present invention, the semiconductor wafer and the resin layer are collectively cut using a dicing blade, so that the cutting edge of the dicing blade is worn by the filler contained in the resin layer, and new abrasive grains are always added. It can be expressed. Thereby, even if dicing is continuously performed, there is an effect that a high-quality semiconductor device can be manufactured without deterioration of the dicing blade.

FIG. 1 is a cross-sectional view showing steps in a first embodiment of a method for manufacturing a semiconductor device according to the present invention. FIG. 2 is a flowchart showing steps in the first embodiment of the semiconductor device manufacturing method according to the present invention. FIG. 3 is a cross-sectional view showing steps in the second embodiment of the method for manufacturing a semiconductor device according to the present invention. FIG. 4 is a view showing an image of a cross section cut by a dicing blade as an experimental example of the method for manufacturing a semiconductor device according to the present invention. FIG. 5 is a diagram showing an image of a cross section cut by a dicing blade as an experimental example of the method for manufacturing a semiconductor device according to the present invention.

A semiconductor device manufacturing method according to a first embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view illustrating steps of a method for manufacturing a semiconductor device according to the present embodiment, and FIG. 2 is a flowchart illustrating steps of the method for manufacturing a semiconductor device according to the present embodiment. It is a semiconductor wafer.

  In this embodiment, as shown in FIG. 2, it has a filler-containing resin layer forming step S2 and a dicing step S3, and these are shown in FIG. As described above, a semiconductor wafer W0 having a plurality of device formation regions is prepared so that the regions 13 in which the devices are formed are separated from each other by a dicing line 12 having a predetermined width dimension.

The semiconductor wafer W0 is made of, for example, silicon. A plurality of device regions 13 are formed on the surface of the semiconductor wafer W0. In addition, a dicing line 12 serving as a portion for cutting the semiconductor wafer W0 in the subsequent dicing step S3 is provided between the adjacent device regions 13. A plurality of device regions 13 in which devices such as ICs and memories are formed are formed on the surface of the semiconductor wafer W0 so as to be separated from each other with a predetermined width as dicing lines 12. In this embodiment, the width of the dicing line A is set to be about 10 to 20% larger than the width dimension of the dicing blade of about 150 μm.
The semiconductor wafer W0 may be subjected to a thinning process by back grinding (backside polishing) using mechanical means, chemical means, and a combination of these means.

[Filler-containing resin layer forming step S2]
In the filler-containing resin layer forming step S2, as shown in FIG. 1B, as a wafer level package processing step, the filler-containing resin layer 14 is formed on the entire surface of the semiconductor wafer W0.
The filler-containing resin layer 14 is a protective resin layer for protecting the device region 13 and is formed on the entire surface of the semiconductor wafer W0, but is formed excluding the portion 15 for forming bumps as necessary. The filler-containing resin layer 14 is formed by application such as spin coating method, dipping method, roll coating method, spray method, or means formed by sticking as a sheet, and heat treatment is performed thereon. Alternatively, it can be formed using a photolithography process.

The filler-containing resin layer 14 contains a filler.
This filler is one of the additives mixed in the resin, and is used for the purpose of improving the performance of the resin and imparting functions. In the present embodiment, the average particle size is about 0.3 to 1.0 μm, which is smaller than abrasive grains contained in a dicing blade described later. The ratio of the average particle size of the abrasive grains and filler contained in the dicing blade is set to be, for example, about 10 μm / 0.3 μm = 30, in other words, in the range of 10 to 500.
Further, the Mohs hardness of the filler is set to 3 or more and 8 or less, and can be made of, for example, an inorganic material or an organic material such as silica or barium sulfate. When the Mohs hardness of the filler is less than 3, it is difficult to obtain the effect of wearing the cutting edge of the dicing blade. When the Mohs hardness is higher than 8, the cutting edge of the dicing blade is damaged, and high-quality dicing becomes difficult. .

[Dicing step S3]
In the dicing step S3, as shown in FIG. 1C, a dicing blade (not shown) made of silicon in which abrasive grains having an average particle size of about 4 to 10 μm are incorporated with a predetermined concentration is rotated at a high speed. Then, the object to be cut is cut by being brought into contact with each other and diced into chips 18 that are separated.
In the dicing process of this embodiment, the filler-containing resin layer 14 and the semiconductor wafer W0 are cut together at the time of cutting with a dicing blade.

By cutting the filler-containing resin layer 14 and the semiconductor wafer W0 together, the filler serves as abrasive grains for the dicing blade. Even when the blade is clogged or clogged, by continuing the cutting, the dicing blade is worn by the filler and new abrasive grains are conspicuous. As a result, the abrasive grains of the dicing blade can maintain a state where normal cutting is possible.
Accordingly, it is possible to prevent the abrasive particles of the dicing blade from becoming clogged, causing crushing, and causing the chipping generated by applying a load to the cutting portion to become so large as to reach the device formation region.

  Chipping is generated by applying a force different from normal to the semiconductor wafer when the abrasive grains in the blade are clogged and clogged. However, by cutting the semiconductor wafer W0 together with the filler-containing resin layer 14 containing the filler, the filler plays the role of abrasive grains, and cutting can be performed without causing any chipping even when the blade is clogged. Is possible.

  In the present invention, the filler-containing resin layer forming step S2 for forming the filler-containing resin layer 14 containing the filler on one surface of the semiconductor wafer W0, and the semiconductor wafer W0 and the filler-containing resin layer 14 using the dicing blade are collectively performed. And the dicing step S3 for cutting the semiconductor wafer W0 into pieces, the cutting edge of the dicing blade is conspicuous by the filler contained in the filler-containing resin layer 14, and new abrasive grains are always exposed. The state to be made can be maintained. Thereby, even if it continues dicing, a dicing blade does not deteriorate. As a result, a high-quality semiconductor device with reduced chipping defects can be manufactured.

  In the present invention, since the average particle size of the filler is set smaller than the average particle size of the abrasive grains of the dicing blade, the cutting edge of the dicing blade is not damaged by the filler that is too large.

  In the present invention, when the Mohs hardness of the filler is set to 3 or more and 8 or less, the cutting edge of the dicing blade can be more effectively worn.

Hereinafter, a second embodiment of a method of manufacturing a semiconductor device according to the present invention will be described with reference to the drawings.
FIG. 3 is a cross-sectional view showing the steps of the semiconductor device manufacturing method according to the present embodiment. The present embodiment is different from the first embodiment shown in FIG. 1 in that a glass substrate W1 is bonded to a semiconductor wafer W0. Description is omitted.

  In the present embodiment, as a substrate preparation step S1, which is a previous step, as shown in FIG. 3A, a composite substrate in which a glass substrate W1 is attached to the back surface of a semiconductor wafer W0 is prepared. Thereafter, as in the first embodiment, as shown in FIG. 3B, the filler-containing resin layer 14 is formed as the filler-containing resin layer forming step S2.

[Dicing step S3]
In the dicing step S3 in the present embodiment, as shown in FIG. 3 (c), a dicing blade (not shown) in which abrasive grains having an average particle size of about 4 to 10 μm are incorporated with a predetermined concentration is rotated at high speed. The object to be cut is cut by bringing it into contact with the body, and dicing is performed so that each chip 18 is obtained.
In the dicing process of this embodiment, the filler-containing resin layer 14, the semiconductor wafer W0, and the glass substrate W1 are cut together at the time of cutting with a dicing blade.

In the dicing step S3, the filler-containing resin layer 14, the semiconductor wafer W0, and the glass substrate W1 are cut together so that the filler serves as abrasive grains for the dicing blade. Even when the blade is clogged or clogged, by continuing the cutting, the dicing blade is worn by the filler and new abrasive grains are conspicuous. As a result, the abrasive grains of the dicing blade return to a normal cutting state, and the semiconductor wafer W0 and the glass substrate W1 are cut together.
Accordingly, it is possible to prevent the abrasive particles of the dicing blade from becoming clogged, causing crushing, and causing the chipping generated by applying a load to the cutting portion to become so large as to reach the device formation region.

According to the present invention, a glass substrate is bonded to the other side of the semiconductor wafer, and the glass substrate is also cut at the same time in the dicing process, so that even if it is a composite substrate in which the blade is likely to deteriorate, high quality A simple semiconductor device can be manufactured.
Conventionally, when a wafer bonded with glass is cut with a normal silicon blade, a special blade called a resin blade is required. This resin blade has a blade that is smaller than that of a silicon blade. Since it is thick and prone to chipping, the influence on the deterioration of the quality of the semiconductor device was considerably large, but this problem can be solved.

Experimental examples according to the present invention will be described below.
FIG. 4 shows an image of a cross section obtained by laminating the filler-containing resin layer 14 on the semiconductor wafer (silicon wafer) W0 and cutting with a dicing blade as in the embodiment described above.
Here, the filler has an average particle size of about 0.5 μm and is made of a mixture of silica having a Mohs hardness of 6.5 or barium sulfate having a Mohs hardness of 3.5 to 4, and the dicing blade has an average particle size Abrasive grains having a diameter of about 4 to 10 μm are made of silicon incorporated with a predetermined concentration.

From the result of FIG. 4, it can be seen that no large chipping of the silicon wafer occurs near the interface between the filler-containing resin layer 14 and the silicon wafer W0. This means that the dicing blade was abraded by the filler contained in the filler-containing resin layer 14, and good dicing without chipping was realized.
Similarly, FIG. 5 shows an image of a cross section obtained by laminating a resin layer 14 that does not contain a filler on a semiconductor wafer (silicon wafer) W0 and cutting it with a dicing blade.
From the result of FIG. 5, it can be seen that chipping of the silicon wafer occurs. In the drawing, the portion surrounded by a broken-line circle is a portion where a crack or a cavity is generated in the silicon wafer WO, that is, a chipping occurrence portion.

  In this way, when the silicon wafer WO and the resin layer are cut at once, the cutting edge of the dicing blade is worn by the filler contained in the resin layer to constantly expose new abrasive grains, thereby continuing dicing. It can be seen that the presence or absence of the filler affects whether the dicing blade does not deteriorate and chipping occurs.

W0 ... Semiconductor wafer W1 ... Glass substrate 12 ... Dicing line 13 ... Device region 14 ... Filler-containing resin layer

Claims (4)

A filler-containing resin layer forming step of forming a resin layer containing a filler on one surface of a semiconductor wafer;
A dicing step of cutting the semiconductor wafer and the resin layer together using a dicing blade to separate the semiconductor wafer;
A method for manufacturing a semiconductor device, comprising:   2. The method of manufacturing a semiconductor device according to claim 1, wherein an average particle size of the filler is set smaller than an average particle size of abrasive grains contained in the dicing blade.   3. The method of manufacturing a semiconductor device according to claim 1, wherein the filler has a Mohs hardness of 3 or more and 8 or less.   4. The method of manufacturing a semiconductor device according to claim 1, wherein a glass substrate is bonded to the other surface side of the semiconductor wafer, and the glass substrate is also collectively cut in the dicing process. 5. .