JPH11283938A - Dicing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct a cutting position for preventing errors of the cutting position before cutting, by correcting a stored street spacing corresponding to the amount of deviation between a formed street and a street, that is subjected to indexing and is sent out based on the stored street. SOLUTION: A street S1 is detected by an optical means, where the street S1 is formed in a region A of a semiconductor wafer. Also, a street 2 of a region B is detected by the optical means at a position, where the indexing and sending is made by the amount of street spacing being stored in advance. Then, the street S1 is compared with the street S2. When they do not match, an amount of deviation x μm in a Y-direction is measured by image processing. The amount of deviation of x μm is used as a correction value, and the street spacing stored in advance is corrected for dicing while indexing, and sending is made, thus cutting the center of the street without errors.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for dicing a street formed on a semiconductor wafer using a dicing apparatus. More specifically, an error occurs in a cutting position by correcting the cutting position before cutting. The present invention relates to a dicing method that avoids the above in advance.

[0002]

2. Description of the Related Art On a surface of a semiconductor wafer W before being diced shown in FIG. 6, a plurality of linear regions having a predetermined width and arranged in a grid at predetermined intervals are arranged in a vertical and horizontal direction. And a circuit pattern is applied to a rectangular area defined by the street S. And
Such a semiconductor wafer W is diced using a dicing apparatus 10 as shown in FIG.

When dicing a semiconductor wafer W using a dicing apparatus 10, the semiconductor wafer W is held on a frame F via a holding tape T and is suction-held on a chuck table 11. Then, the semiconductor wafer W held on the chuck table 11 is first positioned directly below the optical unit 12 by moving the chuck table 11 in the X-axis direction.

The optical means 12 is movable in the Y-axis direction, and magnifies and images the surface of the semiconductor wafer W while moving in the Y-axis direction. Then, pattern matching between a pattern previously stored in the storage means 13 such as a memory and an image obtained by imaging is performed, and a street S to be cut is detected. The movement of the optical means 12 is stopped at the position where the street S to be cut is detected, and the chuck table 11 is moved in the X-axis direction to receive the action of the cutting means 14.

Here, as shown in FIG. 8, the cutting means 14 has a configuration in which a rotary blade 18 is mounted on a spindle 17 rotatably supported by a drive source 16 in a spindle housing 15.

The movable portion 19 connected to the end of the spindle housing 15 is provided with a ball screw 2 arranged in the Z-axis direction.
The movable portion 19 is vertically moved as the ball screw 20 is rotated by being driven by a driving source 21 connected to the ball screw 20, and the spindle housing 15 is also vertically movable. The position information of the spindle housing 15 in the Z-axis direction is detected by the linear scale 22, and is used for precise control of the movement in the Z-axis direction.

The wall 2 on which the ball screw 20 is disposed
3 is screwed with a ball screw 25 arranged in the Y-axis direction. The base 24 is driven by a driving source 26 connected to the ball screw 25 and rotates as the ball screw 25 rotates. The table 24 is also movable in a required range in the Y-axis direction. Then, the position information of the base 24 in the Y-axis direction is detected by the linear scale 27 and used for precise control of the movement in the Y-axis direction.

Further, as shown in FIG. 9, the spindle housing 15 and the optical means 12 are connected to a common base and arranged in parallel, and the rotating blade 18 and the optical means 1 are arranged in parallel.
2 and the position in the Y-axis direction are equal. Accordingly, when the optical means 12 moves in the Y-axis direction, the rotating blade 18 also moves by the same amount in the same direction in conjunction with the movement, and the rotating blade 18 and the center of the optical means 12 are always positioned in a straight line. Is kept.

Street S to be cut by optical means
Is detected, the cutting means 14 descends while the rotating blade 18 rotates, and the chuck table 11
By moving in the axial direction, the detected street S
Is cut by the rotating blade 18.

When cutting the next street,
The indexing and feeding means 28 refers to the street interval stored in the storage means 13 in advance, moves the cutting means 14 in the Y-axis direction by the street interval, and
, And the position of the rotary blade 18 in the Y-axis direction is positioned at the next street to be cut. When the cutting means 14 is lowered while rotating the rotary blade 18 and the chuck table 11 is moved in the X-axis direction, the next street is cut. By sequentially indexing and feeding the rotating blades 18 in this manner, streets can be cut one after another.

[0011]

However, the ball screw 25 and the linear scale 27 may thermally expand, and if these expand thermally, an error may occur in the indexing feed of the rotary blade 18. In addition, the spindle 17 may also thermally expand, and in this case, an error occurs in the position of the rotating blade 18 indexed and fed. If an error occurs in the index feed as described above, a deviation occurs in the cutting position.

Further, there may be an error between the street interval stored in the storage means 13 and the actual street interval of the semiconductor wafer W. In such a case, an error occurs in the cutting position.

Further, a ball screw 25, a linear scale 2
7. If there is an error between the street interval stored in the storage means 13 and the actual street interval along with the thermal expansion of the spindle 17, the combination of these causes a shift in the cutting position.

As described above, when the cutting position is shifted,
There is an inconvenience that a portion other than the street that should not be cut is cut and the chip is damaged.

On the other hand, after cutting the street, the position of the cut groove formed by the cutting is confirmed by the optical means 12 and the deviation from the center of the street is detected to detect the error of the index feed amount. In the past, performing subsequent cutting in consideration of this error has been performed,
In this case, there is a problem that a deviation at the time of the first cutting cannot be detected.

Therefore, even if the ball screw, the linear scale, and the spindle have thermal expansion, there is also an error between the street interval stored in the storage means and the actual street interval of the semiconductor wafer W. However, there is a problem to be solved by always performing precise cutting from the beginning without being affected by these.

[0017]

SUMMARY OF THE INVENTION As specific means for solving the above-mentioned problems, the present invention comprises at least an optical means for detecting a street formed on a semiconductor wafer, and a method for cutting a street detected by the optical means. A cutting means having a rotating blade, an indexing means for relatively moving the semiconductor wafer and the cutting means to index and feed the rotating blade to a street to be detected next, and a street interval to be indexed and sent in advance. A first step of detecting a street formed on a semiconductor wafer by an optical means, and performing indexing and feeding based on a street interval previously stored in the storage means, in a dicing apparatus including a storage means stored therein. The second step and the street after being indexed and sent by optical means A third step of outputting, a fourth step of confirming whether the street detected in the first step and the street detected in the third step match, and a fourth step of: Street detected in step and 3rd
If it is confirmed that the detected street matches the detected street, the correction value is set to 0. If it is determined that the street does not match, the deviation amount is measured, and the deviation amount is stored in the storage means as a correction value. There is provided a dicing method comprising: a fifth step of storing; and a sixth step of performing dicing while indexing and feeding a rotating blade based on a street interval and a correction value stored in storage means. Things.

Further, the present invention provides at least an optical means for detecting a street formed on a semiconductor wafer, a cutting means provided with a rotary blade for cutting the street detected by the optical means, a semiconductor wafer and the cutting means. And indexing means for relatively moving and indexing and sending the rotating blade to the next street to be detected,
In a dicing apparatus including a storage unit in which a street interval to be indexed and sent is stored in advance, a street formed on a semiconductor wafer is detected by an optical unit, and a center line of the street and a hairline formed in the optical unit are detected. A first step of matching, a second step of performing indexing based on a street interval stored in advance in the storage means, and a third step of detecting a street after indexing by optical means. A fourth step of checking whether the hairline matches the centerline of the street detected in the third step, and the hairline matches the centerline of the street detected in the third step. If it is confirmed, the correction value is set to 0, and if the A fifth step of measuring a shift amount and storing the shift amount as a correction value in the storage means, and indexing and sending the rotating blade based on the street interval and the correction value stored in the storage means. And a sixth step of performing dicing.

According to such a dicing method, when the ball screw, the linear scale, and the spindle constituting the cutting means have thermal expansion, or when the street interval stored in the storage means and the actual street interval are provided. Even if there is an error, the rotating blade can be positioned on the street in consideration of the error. Further, since the distance to be indexed and fed before cutting can be calculated in advance based on the measured correction value, it is possible to always perform cutting without deviation from the beginning.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a dicing method according to the present invention will be described with reference to a flowchart shown in FIG. Note that the dicing apparatus used in the embodiment of the present invention may be configured in the same manner as the dicing apparatus 10 described in the related art, and in this embodiment, the semiconductor device is manufactured using the dicing apparatus 10 shown in FIG. A case in which dicing of a wafer is performed will be described as an example.

First, the chuck table 11 is positioned immediately below the optical means 12 to detect, for example, a street S1 formed in the area A of the semiconductor wafer W shown in FIG. In this case, as in the related art, the surface of the semiconductor wafer W is imaged as shown in FIG. 3A while the optical unit 12 is moved in the Y-axis direction as necessary, and stored in the storage unit 13 in advance. Pattern matching with the existing pattern. Then, at the time of the matching, the image at that time is stored in the storage means 13 (first step).

Next, by the indexing and sending means 28, the street interval (y) stored in the storage means 13 in advance is used.
μm), the cutting means 14 is moved and the rotary blade 18 is indexed and fed (second step). Then, the street S2 of the area B at the position after the index feed is detected again by the optical means 12 (third step).

Next, the image of the street S1 stored in the storage means 13 in the first step is compared with the image of the street S2 stored in the storage means 13 in the third step. It is checked whether it is (fourth step).

As a result, when they match, the thermal expansion of the ball screw 25, the linear scale 17, and the spindle 17 and the distance between the street interval stored in the storage means 13 and the actual street interval of the semiconductor wafer W are determined. Since no error occurs, the correction value is set to 0 and stored in the storage means (fifth step).

On the other hand, as shown in FIG. 3B, when the two streets do not match, the shift in the Y-axis direction is measured by image processing, and this shift (xμm) is stored in the storage means as a correction value. It is stored (fifth step).

When the correction value x μm is stored in the storage means 13 in this way, the indexing and feeding means 28 refers to the correction value x μm when cutting, and is a value obtained by subtracting the correction value x from the street interval y (y -X) By indexing and feeding by μm, the center of the street can be cut without error.

The center of the street can be cut without error by the method shown in the flowchart of FIG. 4 in the same manner as described above. That is, in the method of FIG. 4, FIG.
As shown in FIG.
The center line 1 is matched with the hair line 30 formed on the optical means 12 (first step), and then the indexing is performed based on the street interval stored in the storage means 13 (second step). ), The street S2 after the index feed is detected by the optical means 12 (third step).

Then, it is confirmed whether or not the hairline 30 matched with the center line of the street S1 in the first step matches the centerline of the street S2 detected in the third step (fourth step). If they match, the correction value is set to 0, and if they do not match, the hairline 30 and the center line 31 shown in FIG.
Is stored in the storage unit 13 as a correction value (fifth step). When the correction value is stored in the storage unit 13 in this way, the indexing and sending unit 28 sends out the index by (y−x) μm which is a value obtained by subtracting the correction value x from the street interval y stored in the storage unit 13. Thus, the center of the street can be cut without error (sixth step).

[0029]

As described above, according to the dicing method according to the present invention, when the ball screw, the linear scale, and the spindle constituting the cutting means have thermal expansion, the street interval stored in the storage means and Even if there is an error with the actual street interval, the indexing distance can be adjusted in consideration of the error. Further, since the distance to be indexed and fed before cutting can be calculated in advance based on the measured correction value, it is possible to always perform cutting without deviation from the beginning. Therefore, dicing can be performed without damaging the chip, and chip quality and yield are improved.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating a dicing method according to the present invention.

FIG. 2 is a plan view showing a semiconductor wafer diced by the dicing method.

FIG. 3A is an explanatory view showing a street of a semiconductor wafer in an enlarged manner. (B) is an explanatory view showing, on an enlarged scale, a street after indexing and sending a semiconductor wafer.

FIG. 4 is a flowchart illustrating a dicing method according to the present invention.

FIG. 5A is an explanatory diagram showing a street and a hairline of a semiconductor wafer in an enlarged manner. (B)
It is explanatory drawing which expanded and showed the street and the hairline after index sending of a semiconductor wafer.

FIG. 6 is a plan view showing a semiconductor wafer held by a frame.

FIG. 7 is a perspective view showing the appearance of a dicing apparatus for dicing a semiconductor wafer.

FIG. 8 is an explanatory diagram mainly showing a configuration of a cutting means and its periphery in the dicing apparatus.

FIG. 9 is an explanatory diagram showing a positional relationship between an optical unit and a rotating blade in the dicing apparatus.

[Explanation of symbols]

10 Dicing device 11 Chuck table
12 Optical means 13 Memory means 14 Cutting means 15 Spindle housing 16 Drive source 17 Spindle 18 Rotating blade 19 Movable part 20 Ball screw 21 Drive source 22 ... Linear scale 23 ... Wall 24 ... Base 25 ... Ball screw 26 ... Drive source
27 Linear scale 28 Indexing means 30 Hairline 3
1 ... Center line

Claims (2)

[Claims] At least an optical unit for detecting a street formed on a semiconductor wafer, a cutting unit provided with a rotary blade for cutting a street detected by the optical unit, and the semiconductor wafer and the cutting unit A dicing apparatus comprising: indexing means for relatively moving the rotating blade to index and send the rotating blade to the next street to be detected; and storage means in which a street interval to be indexed and sent is stored in advance. A first step of detecting a street formed on a semiconductor wafer; a second step of performing indexing based on a street interval stored in advance in the storage means; A third step of detecting by optical means, and a detection in the first step A fourth step of checking whether the streets detected in the third step match the streets detected in the third step; and, in the fourth step, the street detected in the first step and the street detected in the third step. If it is confirmed that the values match, the correction value is set to 0.
If it is determined that they do not match, the shift amount is measured and the shift amount is stored in the storage unit as a correction value.
And a sixth step of performing dicing while indexing and feeding the rotating blade based on the street interval and the correction value stored in the storage means. 2. At least an optical unit for detecting a street formed on a semiconductor wafer, a cutting unit provided with a rotary blade for cutting a street detected by the optical unit, and the semiconductor wafer and the cutting unit A dicing apparatus comprising: indexing means for relatively moving the rotating blade to index and send the rotating blade to the next street to be detected; and storage means in which a street interval to be indexed and sent is stored in advance. A first step of detecting a street formed in the semiconductor wafer and matching a center line of the street with a hairline formed in the optical means; and determining the street based on a street interval previously stored in the storage means. The second step of performing the feed, and the street after the index feed A third step of detecting whether the hairline matches the center line of the street detected in the third step; and a third step of determining whether the hairline matches the centerline of the street detected in the third step. In the case where it is confirmed that the center line of the detected street matches, the correction value is set to 0, and when it is confirmed that the center line does not match, the amount of deviation is measured and the amount of deviation is stored as a correction value in the storage. And a sixth step of performing dicing while indexing and feeding the rotating blade based on the street interval and the correction value stored in the storage means. .