JPH01231340A - Semiconductor wafer and mask for manufacture thereof - Google Patents

Abstract

PURPOSE:To remove a semiconductor device not related to a theoretical yield in the peripheral region of a semiconductor wafer positively on the basis of the result of the detection of the amount of light from the surface of the semiconductor, device before it is used for die bonding by making a wiring region of the semiconductor device in the peripheral region narrower than a wiring region of the semiconductor device in a region inner than the peripheral region. CONSTITUTION:Wiring regions in semiconductor devices 3 in a peripheral region 2 are made narrower than wiring regions in semiconductor devices inner than the peripheral region. Consequently, only wiring films as uppermost layers or the wiring films as the uppermost layers and wiring films as layers lower than the wiring films as the uppermost layers in the semiconductor pellets 3 in the peripheral region 2 are not formed completely in a wafer 1. According to such a wafer 1, the amounts of light of the pellets 3 are insufficient positively in decision discriminating a nondefective or a defective from the integral value of video signals acquired by image-sensing the surfaces of the semiconductor pellets after dicing and before die bonding, thus surely removing the pellets 3 from a process before die bonding.

Description

[Detailed description of the invention] The present invention will be described in the following order.

A. Industrial field of application B6 Summary of the invention C9 Background art [Fig. 3 D9 Problems to be solved by the invention [Fig. 4] E1 Means for solving the problems F6 Effects G. Examples [Fig. [Figure 1, Figure 2] Effects of the H8 invention (A, industrial application field) The present invention is directed to semiconductor wafers and masks used in their manufacture, especially when semiconductor devices in the peripheral area that are outside the theoretical yield are removed from the surface of the wafer. The present invention relates to a semiconductor wafer that can be reliably determined to be a defective product based on the detection result of the amount of light, and a mask used for manufacturing the semiconductor wafer.

(B. Summary of the Invention) The present invention provides a method for reliably detecting semiconductor devices with outside the theoretical yield in the peripheral area of a semiconductor wafer based on the detection result of the amount of light from the surface of the semiconductor device before being subjected to die bond deinking. In order to allow for quick removal, the wiring area of the semiconductor device in the peripheral area is made narrower than the wiring area of the semiconductor device inside the peripheral area.

(C, Background Art) [Figure 3] In IC5LSI, VLSI, etc., a large number of semiconductor devices are simultaneously formed on a single semiconductor wafer, and a needle (
After that, the semiconductor wafer is diced and separated into individual semiconductor devices (semiconductor pellets), and then the semiconductor devices are die-ponded into IC packages etc. using a die-ponder. Can be assembled.

By the way, in a die bonder, in order to prevent a large waste such as a package being wasted due to die bonding of a defective semiconductor pellet, for example, a third Measure the level of video No. 45 as shown in the figure,
For example, whether the product is defective or non-defective is determined based on whether or not the value is within a predetermined range (between the level that defines the -L limit and the two levels that define the lower limit). It is made so that it does not adsorb to the collect and is not subjected to die-ponding. The distinction between good and defective products is, in terms of physical appearance,
The light reflectance differs between the wiring area, such as aluminum 81, on the semiconductor pellet surface and the other areas, and the value obtained by scanning the surface of the semiconductor device and integrating the amount of light from the surface determines the type of IC. This is done by utilizing the principle that the value is determined by itself, and if the value is not within a certain range, it can be determined that the product is defective.

In addition, for semiconductor pellets that are determined to be defective in the pellet check performed at the stage before dicing (since they have not been diced yet, they should be referred to as pellets rather than pellets, but for convenience, they are called pellets). A black or other defective ink mark is automatically placed on the surface. In this way, when determining whether a defective semiconductor pellet is a good product or a defective product based on the detection result of the light rl from the surface of the semiconductor pellet during die bonding after dicing, the light wall is insufficient and the product is judged as a defective product. This is because it can be determined and removed from the die bonding target.

(D. Invention or problem to be solved) [Figure 4] By the way, semiconductor pellets have a square or rectangular shape, whereas semiconductor wafers are basically circular, so the surrounding area of the semiconductor wafer This results in an incomplete semiconductor pellet (hereinafter referred to as a "half-chip semiconductor pellet") in which a portion of the region is notched. This should naturally be a defective product, but it is determined to be a defective product after dicing and before tie bonding, and is removed from the process without being adsorbed by the vacuum collet. It is a bad item and should also be treated as a defective product (marked with defective ink) by pellet check. Despite this, there have been cases where the material has been attracted to the vacuum collet and die-pond, or it has been stuck in the vacuum suction hole of the vacuum collet. If the chipped conductor pellets are tied-boarded, a large amount of waste will occur, and if the vacuum suction holes become clogged with the chipped semiconductor pellets, a more serious problem will occur.

This is because even if a half-chip semiconductor pellet is clogged, it is not impossible for air to pass through the vacuum suction hole, and if you continue die-ponding on other semiconductor pellets in that state, die-ponding will automatically occur. '4j It can happen as long as it has been said.

As a result, the surface of the semi-chip semiconductor pellets clogged in the vacuum suction hole or the semiconductor pellets that are successively suctioned by the vacuum collet may be damaged, and the entire lot may be defective due to the scratches. It is.

This can happen because, as mentioned above, firstly, a semi-chip semiconductor pellet may not be determined to be a defective product when determining whether it is a good product or a defective product after dicing and before die bonding. This occurs because even if the semiconductor pellet is slightly chipped, the amount of light may not be insufficient and the amount of light may still be within the standard depending on the condition of the wiring area of the semiconductor pellet or the way the light is reflected. It is.

Second, because the bullet check is not performed on half-chip semiconductor pellets in the peripheral area of the semiconductor wafer, even though the half-chip semiconductor pellets are defective, they are not marked as defective with ink. This is because it will be done. To explain this point in detail, a bullet check should originally be performed on all semiconductor pellets, regardless of whether they are solid or not. This is done by applying a predetermined needle pressure, and is equipped with a complicated mechanism that ensures that the pressure of each measuring needle is a predetermined strength. However, as shown in FIG. 4, d! When you try to hit the fixed needle C, C1...
An unbalance of pressure occurs between the needles c, c,... that hit the bullet b and the needles C1C1... corresponding to the chipped parts, and each d! 11. There is a risk that the mechanism that tries to maintain the pressure of the fixed needle at a certain value may go awry or may even malfunction.

Therefore, the pellet check is not performed on the i-conductor pellets in the surrounding area where there are half-chip semiconductor pellets, that is, semiconductor pellets with outside the theoretical yield (by the computer program that controls the automatic measuring device, The actual situation is that the measurement target can be set arbitrarily using software. Therefore, 'I! outside the theoretical yield! - Conductor pellets are diced without inking defective marks;
It becomes impossible to determine whether a product is good or defective based on the detection results of stars of light from the surface of the semiconductor pellet. Therefore, if it is determined that the product is defective, there is a possibility that the half-chip semiconductor pellet will clog the vacuum suction hole as described above. Although the probability of this happening is very low, if it happens once, all lots will be defective, which could result in huge losses.

The present invention has been made to solve these problems, and when semiconductor devices in the peripheral area of a semiconductor wafer with outside the theoretical yield are subjected to die bonding, the amount of light from the surface of the semiconductor device is reduced. The purpose is to ensure removal based on the detection results.

(E. Means for Solving the Problems) In order to solve the above problems, the present invention makes the wiring area of the semiconductor device in the peripheral area narrower than the wiring area of the semiconductor device in the area inside the peripheral area. It is characterized by the fact that it is made to be.

(F. Effect) According to the present invention, the wiring area of the semiconductor device in the peripheral area is
Since the peripheral area is made smaller than the wiring area of the semiconductor device inside, the semiconductor device in the peripheral area is judged to be defective by judgment based on the detection result of the amount of light from the surface of the semiconductor device, without performing a pellet check and marking it as defective. This can be determined reliably and removed from the process. Therefore, it is possible to reliably prevent an iμ change in which a half-chip semiconductor pellet is attracted to the vacuum collet and becomes clogged.

(G. Embodiment) [FIGS. 1 and 2] Hereinafter, a conductor wafer of the present invention and a mask used for manufacturing the same will be described in detail according to the illustrated embodiment.

FIG. 1 is a plan view showing one embodiment 1 of the semiconductor wafer of the present invention. In the figure, reference numeral 2 denotes a peripheral region (indicated by diagonal lines) of the semiconductor wafer 1, and semiconductor pellets 3, 3, . It should be removed from the process at this stage.

4 is a region inside the peripheral region 2, and semiconductor pellets 5, 5, . . . within the region 4 are ordinary semiconductor pellets. Note that the shape of each semiconductor pellet 5 is complicated and is therefore not shown in the drawings.

In this semiconductor wafer 1, the semiconductor pellets 3.3... in the peripheral region 2 have only the uppermost layer wiring film, or the uppermost F layer wiring film and one more layer wiring film formed thereon. do not have. In this respect, the semiconductor pellets 3.3, . . . in the peripheral region 2 are completely different from the semiconductor pellets 4.4, . That is, originally, a semiconductor pellet has several layers of wiring films made of aluminum, for example, but the semiconductor pellets 3, 3, . At least the uppermost layer wiring film is not formed.

According to such a semiconductor wafer 1, the surface of the semiconductor pellet with die bonding of 0η after dicing is imaged and 1;
In determining whether the product is good or defective based on the 41-minute value of the video signal, the semiconductor pellets 3, 3, .
. . will definitely be insufficient in light quantity, so that the semiconductor pellets 3, 3, . . . in the surrounding area 2 can be reliably removed from the die bonding process. And, semiconductor pellet 3.3... Due to the absence of a wiring film on the surface, light! The judgment result that the product is defective due to lack of 11 is definitely IT! Now, Ushiku is determined to be defective based on the result of the pellet check without having to perform a pellet check on the semiconductor pellets 3, 3, ... in the peripheral area 2. The supposed semiconductor pellet 3.
3. The problem no longer occurs even if the defect mark is not marked with ink. Therefore, the bullet check is performed on the semiconductor bullets 5, 5, . All you have to do is just do it.

FIG. 2 shows an exposure mask 6 for photoetching the wiring film of the semiconductor wafer 1 shown in FIG.

Reference numeral 7 denotes a region inside the peripheral region 2 of the semiconductor wafer 1 in the mask 6. In the region 7, a light shielding layer 1 (made of chromium, for example) having the same pattern as the wiring film to be formed is formed. This light-shielding film has a complicated shape, so it is not shown in the drawings.

Reference numeral 8 denotes a peripheral region (indicated by diagonal lines) outside the region 7, and no light shielding film is formed within the peripheral region 8. In other words, it is so-called white.

Using the mask 7 as shown in FIG. 2, the positive type photoresist on the wiring film (not yet patterned) of the semiconductor wafer 1 shown in FIG. 1 is exposed to light.
If etching is continued, no wiring film will be formed in the peripheral region 2 of the semiconductor wafer 1. Incidentally, when exposing a negative type photoresist, a mask in which a light shielding film is entirely formed in the peripheral region 8 is used.

Incidentally, if a mask 7 as shown in FIG. 2 is used, the yield can be indirectly improved. To explain this point, in general, the mask is completely different from the mask 6 shown in FIG. Many of the patterns required to make one semiconductor pellet are arranged in the same way, so it is not often possible to perfectly match the center 0 of the mask 6 with the center 0 of the semiconductor wafer 1 when aligning the masks. do not have. Therefore, exposure etc. are often performed with some deviation between the two. However, due to aberrations and other problems, the best yield can be achieved when the mask center 0 and the wafer center 0 are perfectly aligned. Therefore, the decrease in yield due to the deviation between the center 0 and the 0 edge cannot be ignored.

However, as shown in FIG. 2, when using the mask 6 in which the peripheral region 8 is outlined (when using a positive type photoresist), the center of the semiconductor wafer 1 and the mask 6. , 0, a part of the peripheral region 8 of the mask 6 will correspond to the inner region 4 of the semiconductor wafer 1, and the defective semiconductor pellet will be placed on the semiconductor wafer l.
Since a large number of them will definitely occur in area 4, it is necessary to perform exposure processing by properly aligning the centers o and o, and as a result, the yield decrease due to the deviation of the center 0.0 is reduced. This will lead to a higher passing rate.

In the above embodiment, the peripheral area 2 of the semiconductor wafer 1
Each of the semiconductor pellets 3.3, . . . had no wiring film on the entire surface. However, the area of the semiconductor pellets 3.3, . . . in the peripheral region 2 is larger than the area of each semiconductor pellet 5.5, . . . in the region 4 inside the peripheral region 2, 1! i! It is sufficient that the area of the region is significantly small, and it is not necessarily necessary that no wiring film exists on the surface of each semiconductor pellet 3, 3, . . . .

(H, Effect of the Invention) As described above, the present invention is characterized in that the wiring area of the semiconductor device in the peripheral area is narrower than the wiring area of the semiconductor device inside the peripheral area. be.

Therefore, according to the present invention, since the wiring area of the semiconductor device in the peripheral area is made narrower than the wiring area of the semiconductor device inside the peripheral area, there is no need to perform a pellet check and mark the semiconductor device as defective in the peripheral area. By making a determination based on the detection result of the amount of light from the surface of the semiconductor device, it is possible to reliably determine that it is a defective product and remove it from the process. Therefore, it is possible to reliably prevent a partially chipped semiconductor pellet from being attracted to or clogging the vacuum collet.

[Brief explanation of the drawing]

FIG. 1 is a plan view showing one embodiment of the semiconductor wafer of the present invention, FIG. 2 is a plan view showing an actual/Ih example of the mask of the present invention, and FIG. 3 is a screen diagram for explaining the background art. The waveform diagram of the image signal and FIG. 4 are cross-sectional views of a semiconductor wafer for explaining the problem. Explanation of symbols 1... Semiconductor wafer, 2... Peripheral area, 3... Semiconductor device in the peripheral area, 4... Area inside the peripheral area, 5... Semiconductor device in the inner area , 6... Mask, 7... Inner area, 8... Surrounding area. Island Fig. 1 3 East 1 degree 16 flat field A Plan view of the device mask Fig. 2 Situation of the vertical stomach video signal - waveform diagram (Seikyo technique removed〒sensou) Fig. 3 Wafer/) Cross-sectional view (problem) (Explanation of points) Figure 4 Procedural Neho Authorization (Spontaneous) December 1988 29E1 Director General of the Japan Patent Office Yoshi 1) Moon Takeshi 2 Name of the invention Semiconductor wafer and mask used in its manufacture 3 Case of person making amendments Relationship Patent applicant address: 6-7-35, Kitashinyo, Tokyo Parts Store Name (2
+8) Sony Corporation 4, Agent Address: Room 6, 703, New House Nishi-Nippori, 2-53-5, Nishi-Nippori, Arakawa-ku, Tokyo Contents of Amendment (1) On page 4, line 8 of the statement tube, "Collect" has been changed to " Corrected to ``Colette.'' (2) In the 800th line F of the specification, "made" is corrected to "made". (3) On page 9, line 1 of the specification, "defective product" is corrected to "good product." (4) On page 11, line 9 of the specification, insert "[or only the underlying wiring film]" between "only" and "or". (5) On page 13, line 14 of the specification, "phenomenon" is corrected to "development."

Claims (2)

[Claims] (1) A semiconductor wafer formed with a plurality of semiconductor devices, characterized in that the wiring area of the semiconductor devices in the peripheral area is narrower than the wiring area of the semiconductor devices in the area inside the peripheral area. wafer (2) A mask having a pattern for simultaneously forming a plurality of semiconductor devices on a semiconductor wafer, characterized in that the wiring area in the peripheral area of the pattern is narrower than the wiring area in the area inside the peripheral area. semiconductor wafer