KR940004953Y1 - Aligning target structure for laser repair - Google Patents

Abstract

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Description

Structure of laser target array target

1 is a layout view of a conventional arrangement target.

Figure 2 is a detailed view of the main portion of Figure 1, showing the structure of a conventional arrangement target.

3 is a layout view of the arrangement target in the conventional stepper equipment.

4 (a) and 4 (b) are laser beams X and Y scans of a conventional array target.

5 is a layout view of the array target according to the present invention.

6 is a detailed view of the main part of Figure 5, showing the structure of the arrangement target according to the present invention.

7 is an X, Y scan of the array target according to the present invention.

8 is a view showing an embodiment of the present invention, an arrangement target arrangement diagram in a wafer chip.

* Explanation of symbols for main parts of the drawings

5: fuse 6: intersection

7: reference point 11: array target

12 semiconductor chip 13: scribe line

14: final insulating film P: maximum reflectance

The invention of the present invention relates to the structure of the laser target array target, and in particular, the structure of the laser target array target suitable for minimizing the error rate during alignment of the laser repair system. It is about.

In the laser rescue equipment, when a laser beam is injected into a fuse in a memory chip (4MDRAM), one of four targets installed in the scribe line of the chip is used to check whether the beam is located at the center of the fuse. After selecting two or more targets to be arranged, scan the laser beam in the X and Y-axis directions for the targets, set the maximum reflectance point, and compare it with the distance (coordinate) of the fuse input to the equipment. In order to determine whether or not the relief is possible, the conventional array target 1 is arranged on the scribe line 3 of each chip 2 as shown in FIG. This arrangement target 1 is in the form of an " L " having a width of 10 mu m and 75 mu m as shown in FIG.

In addition, a final insulating film (Passivation) (4) is formed at the lower side of each of the array targets (1), the size of the opening of the final insulating film (4) has a shape of the letter "A" having a width of 60㎛ 135㎛ mounted. .

In addition, the material of the array target 1 is made of aluminum, and the final insulating film and the PIQ (Polyimid Iso indro quinazo line dione) film on each array target 1 are removed.

In the drawing, reference numeral 5 denotes a fuse installed in the chip, and 72 such fuses 5 are disposed in the chip, and 36 X (Low) fuses (2EA / block) and 36 Y (column) fuses. (4EA / block).

On the other hand, as shown in FIG. 3, in the stamper equipment, three chips are shot in one shot, and the array targets 1 are arranged on the scribe line 3 of each chip 2 so that the laser It is intended to be used as an array target for relief equipment.

The operation of the conventional laser relief array target configured as described above is as follows.

That is, in the laser rescue equipment, when the laser beam is injected into the fuse in the memory chip (4MDRAM), an array target disposed in the scribe line 3 of the chip 2 in order to check whether the laser beam is located at the center of the fuse exactly. (1) Scan the laser beam in (select two or more) and scan it in the X and Y axis directions, and as shown in FIG. 4, the intersection point 6 where the maximum point P of the reflectance intersects to the equipment. By comparing with the coordinates of the input fuse, that is, the reference point 7, it is determined whether or not the chip can be saved, and the relief is performed.

In other words, by comparing the intersection point 6 and the reference point 7, if the scan tolerance (α) is within ± 0.5 μm, the remedy proceeds. If the error range is exceeded, the laser is placed at the center of the fuse within 2 μm of the thickness. It becomes impossible to scan the beam, and the chip is unable to rescue.

Here, the value of the tolerance α ± 0.5 μm is a value calculated in consideration of the distance (coordinate) at which the fuse is fixed from the reference point 7.

However, the conventional array targets as described above should be arranged using only targets C and D, as shown in FIG. 4, so that foreign matters on one side of the target (C or D) due to process problems may cause relief equipment. After scanning the laser beam on the array target and scanning it on the X and Y axes, the maximum reflectance cannot be found. Therefore, the array error occurs and the chip cannot be repaired without a countermeasure.

In addition, as shown in FIG. 3 when working on the stepper, the array target of the overlapping part is broken, so that an array error occurs during laser rescue, and thus, a case where the rescue is impossible frequently occurs.

In other words, if the Tolerance of the pattern due to the array error when working on the stepper exceeds ± 0.3㎛ at maximum, it may cause the array error during the target array in the laser rescue equipment.

Therefore, the present invention has been devised to solve the above-mentioned conventional defects, and the array target is arranged in a + shape, and the shape of the final insulating film on the lower side is also square to form a target in the laser rescue equipment. By arranging four targets can be selected and arranged at the time of arranging, the probability of arranging errors can be reduced to a minimum. This will be described in detail with the accompanying drawings.

That is, as shown in FIGS. 5 and 6, the array targets 11 according to the present invention are formed in a + -shape having a width of 12 µm and 44 µm, respectively, and installed on the scribe line 13 of each chip 12. The final insulating film 14 formed under each of the array targets 11 is formed in a square having a width of 14 µm and a thickness of 40 µm.

The array target 11 is formed of a material such as aluminum or polysilicon.

Referring to the operation and effects of the array target according to the present invention configured as described above are as follows.

As shown in FIG. 7, the laser beam is scanned on the array targets 11 in the chip in the laser relief equipment, and then scanned in the X and Y directions to compare the point where the maximum points of the reflectances cross with the reference point 7. If the tolerance is within ± 0.5㎛, the process of remedy is the same as before, but if array error occurs by scanning targets C and D, that is, the error between intersection point and reference point is more than ± 0.5㎛, If the contrast is not clear because of the foreign matter, the maximum reflectance does not appear. By using the secondary targets A + B, A + C, and B + D, the chip is re-scanned.

In addition, when target C is scanned, foreign matters are on it, so if the maximum reflectance is not found, target B is scanned, target D is scanned by Y to find the maximum reflectance, and remedy. If it is buried and the reflectance does not come out, the target A is used for Y-scanning before remedy.

That is, the scan target can use targets of A + B, A + C, and B + D in addition to C + D. Therefore, the scan target can be reduced to a minimum by using the C + D target. have.

On the other hand, in order to use the auxiliary targets A and B as described above, the target position (coordinates) is entered into the equipment setup file (set up file) so that a program can be arbitrarily selected from the targets A, B, C, and D on the menu. If you do, it will be available.

As described above, the array target according to the present invention forms four targets (C + D, A + B, A + C, and B + C) by forming and installing an array target installed on the scribe line of each chip in a + shape. Since it can be selected and arranged, there is an advantage of minimizing the probability of misalignment when arranging the target in the laser rescue equipment.

That is, in the conventional L-shaped array target, when there is an arrangement error, there is no countermeasure, and the chip which cannot be saved can be saved by applying the + -shaped array target according to the present invention.

8 is a view showing an embodiment of the array target according to the present invention, as shown in the embodiment of the array target according to the present invention, the + -shaped array target 11 is arranged on the upper left and lower right of the wafer chip, respectively. It is characterized by arranging one by one.

In addition, this embodiment has two array targets of one chip in the target array in the laser rescue equipment and the other configuration is similar to the present invention described above.

In the embodiment of the present invention as described above, the arrangement target 11 is not arranged in the scribe line 13, but is arranged in the chip 12 as shown, so that two arrangement targets in the chip are saved when the chip is rescued. This will minimize the array error rate.

That is, by arranging the array target in the chip, as described in the problems of the prior art, there is an effect of minimizing the array error during laser rescue caused by the array target breakage of the overlapping portion.

Claims (6)

In the structure of the laser target array target, the array target 11 installed in the scribe line 13 of each chip 12 is formed into a + shape and the final insulating film 14 below is formed into a square to form a target array. The structure of the laser target array target, characterized in that it is configured to minimize the array error. The structure of a laser rescue array target according to claim 1, wherein the array target (11) is formed with a width of 12 µm and 44 µm. The structure of the laser rescue array target according to claim 1, wherein the size of the opening of the final insulating film (14) is 14 µm in width and 40 µm in mounting. In the structure of the laser rescue array target, the laser rescue array target 11 is arranged at the upper left side and the lower right side of the wafer chip 12 so as to minimize the array error in the target array. Structure of laser target array target. The structure of a laser rescue array target according to claim 4, wherein the array target (11) disposed in the wafer chip (12) is formed in a + -shape having a width of 12 占 퐉 and a mounting 44 占 퐉. The structure of a laser rescue array target according to claim 4 or 5, wherein a square final insulating film (14) having a width of 14 µm and a mounting size of 40 µm is formed below the array target (11).