JPS63237909A - Manufacture of semiconductor device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a method for dividing a plurality of semiconductor integrated circuit pellets arranged on a semiconductor wafer into individual pellet units, and particularly relates to a method for dividing a plurality of semiconductor integrated circuit pellets arranged on a semiconductor wafer into individual pellet units. The present invention relates to a method for manufacturing a semiconductor device in which a cutting groove is formed on a cutting line.

(Prior Art) Semiconductor integrated circuits (ICs) are manufactured by forming a plurality of semiconductor integrated circuit pellets on a semiconductor wafer using various techniques such as diffusion technology and photolithography. A separation groove is formed using a method such as a blade or laser beam irradiation on a cutting line called a scribe line set in the wafer, and then the wafer is divided into individual pellets by splitting the wafer along this groove. This is done by

Conventionally, when cutting grooves for dividing are formed on a scribe line, the depth of the grooves is set to a constant depth within a wafer. For example, the thickness of a wafer with a diameter of about 10 cm is reduced to about 70% or more, and the groove depth is usually 2.
The depth is set at a constant depth in the range of 00 um to 250 um.

That is, in the conventional method, as shown in the plan view of FIG. 3, grooves are formed at a constant depth on the scribe lines 11 in the X and Y directions that intersect with each other formed on the surface of the semiconductor wafer 10. , the depth of the groove 12 formed along the scribe lines in both directions is constant even at point A and point 8 where the scribe lines in both directions intersect, as shown in the cross-sectional views of FIGS. It is.

This method forms grooves with a constant depth, so when a blade is used, machine operations such as setting the cutting blade are easy, and it is often convenient for product production. Used for division.

However, the conventional method described above has a problem in that it is difficult to obtain a sufficient yield. That is, when grooves are formed on a semiconductor wafer and the pellets are separated along the grooves, chipping occurs at the corners of the pellets, which often causes good pellets to become defective. This tendency is particularly noticeable when the length of one side of the pellet is 5 mm or more. Further, even if the pellet does not chip, distortion remains in the semiconductor substrate portion. For example, in a dynamic memory element, this distortion causes a change in the amount of cell charge corresponding to stored logic information, resulting in defective pellets after division, which is extremely inconvenient in terms of yield and reliability. For this reason, some kind of improvement measures have been required in the past.

(Problems to be Solved by the Invention) As described above, in the conventional method, dividing grooves are formed at a constant depth, which causes many problems in terms of yield and reliability.

This invention was made in consideration of the above-mentioned circumstances, and its purpose is to maintain the characteristics of semiconductor integrated circuits before dividing even after dividing into pellets, thereby achieving high yield and high reliability. An object of the present invention is to provide a method for manufacturing a semiconductor device that allows the manufacture of semiconductor devices.

[Structure of the Invention] (Means for Solving the Simple Problem and Its Effects) In the method for manufacturing a semiconductor device of the present invention, cutting lines, [the portions where the cutting lines intersect when forming grooves for dividing pellets in the By making the depth of the groove the deepest and giving different depths to the dividing grooves, chipping and distortion of the corners of the pellets can be prevented when dividing the pellets.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

The method of this invention, as shown in the plan view of FIG.
When forming dividing grooves on the scribe lines 11 in the X and Y directions that are formed on the surface of the wafer 10 and intersect with each other, the point where the scribe lines in both directions intersect, for example, A shown in the figure.
The grooves are formed so that they are the deepest at points and points above.

The specific cross-sectional shape of the groove 12 is shown in FIGS. 1(a) and (b).
shown in the cross-sectional view. When the groove 12 having such a shape is cut on the scribe line from one end of the semiconductor wafer to the other end using a cutting blade, the length of one side of the pellet is one period, and the scribe line is mutually It is obtained by cutting so that the maximum cutting depth is achieved at points A, B, etc. that intersect. Furthermore, such a cutting shape can be easily achieved by adjusting the pressure applied to the blade.

The dividing grooves formed by the method of this invention have the deepest cutting depth at the parts where the scribe lines intersect with each other, so when dividing the wafer into pellets, the corners of the pellets are the most likely to be damaged. It can be easily broken without causing any chips.

Thereby, pellet division can be performed normally.

In addition, by setting the cutting depth at points A and B, where the scribe lines intersect with each other, to approximately 10% or more of the wafer thickness, for example, 300 μm or more when the thickness of the semiconductor wafer is approximately 450 μm, a large It turned out to be effective.

FIG. 2 is a characteristic diagram showing the relationship between pellet long side length (mm) and yield (%) of ICs manufactured by the conventional method and the method of the present invention. are the characteristics of those manufactured by the conventional method. Assuming square pellets, as shown in the figure, when the pellet size exceeds 5 mm, the conventional method causes a significant decrease in yield, but the method of the present invention shows an improvement in yield. That is, when the pellet size is 5 mm or less, the effect of the method of this invention is that the yield is improved by only a few percent compared to that of the conventional method. However, it can be seen that the degree of yield improvement by the method of the present invention increases rapidly from around 5 mm onwards.

In addition, even if there is no noticeable damage to the corners of the pellet,
As described above, distortion may be present inside the substrate. Introducing such distortion may deteriorate the memory retention characteristics of the dynamic memory element or change the resistance value of the diffused resistor often used in general semiconductor devices. However, it has been confirmed that the method of the present invention is effective in this regard as well. Therefore, by using the method of the present invention, highly reliable semiconductor devices can be manufactured at a high yield.

It goes without saying that the present invention is not limited to the above-mentioned embodiments, and that various modifications can be made. For example, in the above embodiment, the case where a cutting blade is used to form the grooves has been described, but this can also be applied to the case where a so-called laser scriber, which forms the grooves by irradiating a laser beam, is used. In some cases, grooves having the shape described above can be obtained by adjusting the laser output.

[Effects of the Invention] As described above, according to the present invention, it is possible to provide a method for manufacturing a semiconductor device that can manufacture a semiconductor device with high yield and high reliability.

[Brief explanation of the drawing]

Fig. 1 is a sectional view for explaining the invention in detail;
The figures are characteristic diagrams for explaining the present invention, FIG. 3 is a plan view of a semiconductor wafer, and FIG. 4 is a cross-sectional view for explaining the conventional method. 10... Semiconductor wafer, 11... Scribe line, 1
2... Groove. Figure 1 Figure 2 Figure 3 X □ y Figure 4

Claims (3)

[Claims] (1) When forming pellet dividing grooves on the cutting lines formed on the semiconductor wafer and set in the boundary area of the semiconductor integrated circuit pellet, the depth of the grooves is the deepest at the part where the cutting lines intersect. A method for manufacturing a semiconductor device, characterized by making the semiconductor device deeper. (2) The method for manufacturing a semiconductor device according to claim 1, wherein the semiconductor integrated circuit pellet has a length of at least one side of 5 mm or more. (3) The method of manufacturing a semiconductor device according to claim 1, wherein the depth of the groove at the intersection of the cutting lines is approximately 70% or more of the thickness of the semiconductor wafer.