JPS6046047A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To enhance the working efficiency of manufacturing a semiconductor device by heating a metal film formed on the surface of a semiconductor substrate along a dicing line of a wafer to generate mechanical distortion on the surface of the substrate, quenching the wafer, and dividing into chips, thereby reducing improper dicing. CONSTITUTION:The surface of a semiconductor substrate 12 is etched substantially along the center line of a scribing line 14 between semiconductor elements 11, thereby forming a groove 15. Metal which mainly contains aluminum is covered thereon, and linear metal film 16 of narrow line width and metal films 161, 162 for electrodes are formed. Then, a large current is flowed from the films 161, 162 to the film 16 to sufficiently heat them, and when a wafer 10 is introduced into water to quench it, the wafer 10 is divided along the scribing line dur to mechanical distortion occurred in the substrate 12, thereby readily dicing the chip of long rectangular shape.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for manufacturing a semiconductor device, and particularly to a method for manufacturing a semiconductor device at the stage of cutting a wafer into chips.

[Technical background of the invention and its problems]

In a series of semiconductor device manufacturing processes, waes on which predetermined elements have been formed and the uni process has been completed are subjected to a die sort test (testing the quality of a large number of semiconductor elements formed on a wafer in the wafer state). After that, it is divided into individual elements to form semiconductor tyrannos. Conventional methods for dividing a wafer into semiconductor chips include the following.

(1) Diamond? Indian scribing method A diamond edge cut is made on a portion of the wafer's dicing line (scribe line), and the wafer is divided into chips along the scribe line. With this method, it is difficult to dice efficiently due to the crystal orientation of the wafer, and a cutting margin of about 30 μm is required, and when considering the wafer torn off with the scribing machine, the scribe line is usually at least 100 μm wide. is necessary. In addition, it has the drawback that wafer cutting chips (silicon chips) are likely to be generated, and the production efficiency is poor and a long manufacturing time is required.

(2) Laser scribing method A laser beam is scanned along the dicing line of the wafer to form a cut groove on the scribe line, and then the Que/S is divided along the cut groove. In this method, the silicon vaporized by the laser beam hardens again and sticks to the wafer, and the heat generated by the laser beam causes the wafer to dry.
There are disadvantages such as the problem that microcracks occur inside the semiconductor chip and deteriorate the characteristics of the semiconductor chip, and the equipment is bulky and expensive.

(3) Guising Two Method This is a method in which the wafer is cut along dicing lines using a dicing saw. This method does not depend on the crystal orientation of the wafer, and has the advantage of having little residual strain.
A certain amount of cutting allowance is required, and the scribe line usually needs to be set to a width of 100 μm or more to account for blurring when cutting with a dicing saw. In addition, silicone waste is likely to be generated, and since water is used when cutting the shrivel, the water and silicone waste mix in a mud-like state, which tends to stain the surface of the shive vise.

In this way, each of the conventional methods of dividing sea urchins has its own drawbacks, and in each case, the size of the sea urchin is 1.1 mm x 37.5 mm, such as the CCD 17 near-eye meso sensor.
Or 1.1 mX 72. When dicing chips having a long side shape such as Ottan, there is a problem in that it is difficult to separate the chips one by one and the yield of chips decreases.

[Purpose of the invention]

The present invention has been made in view of the above points, and it is an object of the present invention to provide a simple semiconductor device manufacturing method that reduces dicing defects, has high work efficiency, and can easily dice long-sided chips. It is something.

[Summary of the invention]

That is, 1! of the semiconductor device according to the present invention! ! In the sending method,
After exposing the surface of the semiconductor substrate by etching along the dicing line of the wafer, a metal film with a narrow line width is deposited on the dicing line with an appropriately extremely thin insulating film interposed therebetween. Then, energize so that the current flows through all of the narrow metal films formed along the scribe line,
This method generates heat in the metal film to generate mechanical strain on the surface of the semiconductor substrate underneath the metal film, then rapidly cools the wafer and divides the wafer into pieces along dicing lines.

In addition, the dicing line of UNINO 1 is equipped with a normal wafer.
In Zorocess, etching is repeated to prevent upper films such as insulating films from adhering, but the appropriate timing for these etchings is determined by adjusting the width of the dicing line at the final stage of the wafer process. It is even better if a narrow groove is formed in the center of the groove by etching, and the metal film is deposited on this groove.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a plan view of a semiconductor wafer 10 having a rectangular chip shape and having a CCDCD linear image sensor.Semiconductor elements 11 forming semiconductor chips are formed in rows and columns on a semiconductor wafer 10. A predetermined impurity region (not shown) is formed in the element 11, and an upper film such as a silicon oxide film, polysilicon, aluminum wiring layer, etc. is stacked on the upper surface of the semiconductor substrate, and PSG (!) is formed on the top of the layer. A thick protective film (silicate glass) is formed.

Another wafer L like this! The area between the semiconductor elements 11 is usually called a scribe line or a dicing line, and is an area where the surface of the semiconductor plate 12 is exposed. That is, in the process of forming the various upper films described above, the material deposited on the scribe line 14 is etched during patterning of the upper film so as to remove it.

After layering such a wafer 10 by a conventional method, it is formed into a layer as shown in FIG. To,
The semiconductor substrate 1 is placed along approximately the center line of the scribe line 14.
The surface part of 2 is etched by ordinary photoetching method,
A groove portion 15 is formed. Note that 13 in FIG. 3 indicates the upper film.

Subsequently, a metal whose main component is aluminum is deposited on this wafer 10 and patterned to form a linear metal film 16 having a narrow line width. At this time, we
As shown in FIG. 1, an electrode metal film 161.16□ is formed over a wide area in the peripheral area where the semiconductor element 11 is not formed.

Next, a die sort test is performed on the semiconductor element 1 formed on the wafer L1, and electrode metal films 161, 1 are formed on both ends of the wafer L1 so as to sandwich the thin linear metal film 16.
A large current is passed through the linear metal film 16 from 62 . At this time, by passing a current through the linear metal film 16, the linear metal film 16 generates heat. Immediately after generating sufficient heat, the wafer 10 is placed in water, for example, and rapidly cooled. here,
The wafer 10 cracks along the silicon scribe line due to mechanical strain generated within the semiconductor substrate 1.

Here, in the past, it was difficult to break the semiconductor chip especially along the long side, but in this case, a cut is made in the wafer 10 along the long side of the chip, and a light external force is applied to the wafer 10. The wafer 10 can be easily made into semiconductor chips.

According to the method described above, the entire scribe line of one wafer can be simultaneously heated and rapidly cooled, so that the wafer can be divided into a large number of semiconductor chips at once.

Furthermore, this method is particularly effective for long-sided semiconductor chips, which have traditionally been difficult to dice, and can improve the yield of chips.

Furthermore, the width of the scribe line has been reduced to about 100% compared to the conventional one.
Since the width can be narrowed from ~150 μm to 50 μm and 8 degrees, the wafer can be used effectively, and the chip yield can also be improved from this point of view.

In this embodiment, a case has been described in which the groove portion 15 is formed along the scribe line 14, but if the semiconductor substrate 12 is thin, it is not necessary to form the groove portion 15. Further, the groove portion 15 may be formed during the wafer process for forming each part of the semiconductor element 10, and similarly, the linear metal film 16 and the electrode metal films 16□, 162 may also be formed during the wafer process. It is good if it is formed at the right time.

In addition, after etching is performed along the scribe line of a predetermined semiconductor wafer to expose the semiconductor substrate surface, a very thin insulating film is formed by oxidation treatment, etc., and then the very thin insulating film on the scribe line is By forming a linear metal film on
Thereafter, the sea urchins may be broken along the scribe line by applying current to the linear metal film 16 and rapidly cooling the sea urchins.

Furthermore, the shape of the electrode metal MI6X r16x is not limited to that shown in FIG. The formation location and shape of the electrode metal film 163 may be changed as appropriate so that current is passed through the electrode metal film 161 e16zt on the periphery of the wafer 10 as one electrode and the electrode metal film 161 e16zt on the periphery of the wafer 10 as the other electrode.

Moreover, the linear metal film 16 and the electrode metal film 161,
As the material for 162, in addition to aluminum-based metals, materials whose main components are high-melting point metals such as molybdenum, tantalum, tungsten, and titanium can be used.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide a simple semiconductor device manufacturing method that reduces dicing defects, has high work efficiency, and can easily dice long-sided chips.

[Brief explanation of drawings]

FIG. 1 is a diagram showing one process of the semiconductor wafer in the method for manufacturing a semiconductor device according to the present invention, and is a sectional view showing the 2N cross section. 10... To semiconductor wafer, 11... Semiconductor element, 1
2... Semiconductor substrate, 13... Upper film, 14... Scribe line, 15... Groove, 16... Linear metal film, 161, J62... Metal film for electrode.

Claims (1)

[Scope of Claims] (Li) A step of etching and etching the semiconductor wafer along the scribe line to expose the semiconductor substrate surface, and forming an extremely thin insulating film as appropriate on the exposed surface of the semiconductor substrate along the scribe line. a step of depositing a metal film through the wafer, a step of applying current to this metal film to generate heat in the metal film along the scribe line, and a process of rapidly cooling the wafer after the metal film generates heat, and then moving the wafer along the scribe line. (2) In the step of exposing the surface of the semiconductor substrate by etching, etching is performed under the area where the metal film is to be formed along the scribe line. A method for manufacturing a semiconductor device according to claim 1, characterized in that the metal film is deposited on the exposed groove on the surface of the semiconductor substrate. A method for manufacturing a semiconductor device according to claim 1 or 2, characterized in that a metal whose main component is aluminum is used as the material. (4) A high melting point metal is used as the material of the metal film. Claim 1 characterized in that a metal is used as a component.
A method for manufacturing a semiconductor device according to item 1 or 2.