JPH0947890A - Working method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a working method improving throughput. SOLUTION: In deciding the working order of a working block, a first candidate is the block nearest to the working completion position on the assumption that working was completed on an object in the preceding working block, and a second candidate is the next nearer block (step 106, 108); within these blocks of the first and the second candidate, the one block the distance of which is shorter from the working completion position of the preceding block to that of the present block is decided to be the next working block (step 110, 112, 114). Consequently, the relative scanning distance of a laser beam, in working the object on a substrate in a step 120, becomes shorter compared with the case in which simply the nearest block is successively worked and, as such, the throughput is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing method, and more particularly to a laser processing method for processing an object to be processed arranged on the substrate in a two-dimensional direction while relatively scanning the substrate with laser light. The present invention relates to a processing method suitable for application to an apparatus, for example, a laser repair apparatus for processing a redundant circuit switching fuse (hereinafter referred to as “fuse”) on a wafer by laser light.

[0002]

2. Description of the Related Art Conventionally, in a laser repair apparatus, an XY stage on which a wafer is placed or an optical axis of a processing laser is moved so that a fuse as a workpiece to be processed on the wafer is placed on the optical axis of the processing laser. The fuse is cut while it is positioned at. Therefore, if there are many processing points (processing points), the fuse (workpiece) to be processed is divided into several blocks due to communication restrictions, and sent from the control unit to the stage to repeat movement and processing for each block. ing.

This will be specifically described, for example, with reference to FIG.
As shown in (A), in a certain chip on the wafer,
When the fuse row group is arranged along the XY two-dimensional direction which is the moving direction of the XY stage, the fuse row group is divided into six blocks from the processing block A to the processing block F as shown in FIG. For example, when machining is started from the machining block A, as shown in FIG. 6, the machining block A [a → a ′] → machining block B [b →
b ′] → machining block D [d ′ → d] → machining block F
[F → f ′] → machining block C [c ′ → c] → machining block E [e → e ′] are sequentially processed with the block closest to the machining end position in each block as the next candidate. It was

[0004]

However, in the above-described conventional machining method, as is apparent from FIG. 6, in order to machine the remaining machining block E after machining the machining block C, the block C is processed. It is necessary to move the laser beam between C and E from C to E relative to the wafer, and this moving time adversely affects the processing capability, that is, it causes a decrease in throughput.

The present invention has been made in view of the disadvantages of the prior art, and an object of the present invention is to provide a processing method capable of improving throughput.

[0006]

According to a first aspect of the present invention, there is provided a processing method for processing a work piece arranged along a two-dimensional direction on the substrate while relatively scanning the substrate with a laser beam. Then, prior to the processing of the work piece in the certain area on the substrate, the work piece existing in the certain area is divided into one or a plurality of blocks in each of the first direction and the second direction. A first step of dividing into blocks; a second step of selecting any one block after the division into blocks and determining the block as a first processed block to be processed first
Steps; the block closest to the machining end position on the assumption that the machining of the workpiece in the first machining block has been completed is the first candidate, and the second closest block is the second candidate. Of the second candidate blocks, the third step of determining the block having the shorter distance from the machining end position of the first machining block to the machining end position of the first machining block as the second machining block to be machined second And; thereafter
From the third processing block to the final processing block,
Similar to the step, a fourth step of determining the shorter processing block from the processing end position of the previous block of the first and second candidates to the processing end position of the block as the next processing block;
Then, a fifth step of processing the workpiece on the substrate in accordance with the processing order determined in the second to fourth steps.

According to this, when determining the block to be machined next in the third and fourth steps, from the machining end position on the assumption that the machining of the workpiece in the previous machining block is completed. The closest block is the first candidate, the second closest block is the second candidate, and the distance from the machining end position of the preceding machining block to the machining end position of that block among these first and second candidate blocks. Is determined as the processing block to be processed next,
The relative scanning distance of the laser light when processing the workpiece on the substrate in the process becomes shorter than that in the case where the closest blocks are sequentially processed in the related art, and the throughput is improved accordingly. In this case, the processing order of the blocks is determined prior to the processing, and the blocks are sequentially processed according to the determined processing order.

According to a second aspect of the present invention, in the processing method according to the first aspect, the processing order of the workpieces in at least one block whose processing order is determined in the third step and the fourth step is It is characterized in that the entire distance from the processing end position of the block before the block to the processing start position of the block to be processed next to the block is set to be short.

According to this, the processing order of the workpieces in at least one block, the processing order of which is determined in the same manner as in the case of the invention described in claim 1, is set to the processing end of the block before the block. Since the overall distance from the position to the machining start position of the block to be machined next to that block is determined to be short, the machining order within the machining block can be changed depending on the situation, so it is possible to change between machining blocks The relative scanning distance of the laser beam between the processing block → the processing block → the next processing block can also be shortened.

According to a third aspect of the present invention, in the processing method according to the second aspect, the processing order of the workpieces in all the blocks whose processing order is determined in the third step and the fourth step is set as follows. It is characterized in that the entire distance from the processing end position of the block before the block to the processing start position of the block to be processed next to the block is determined to be short.

According to this, as a result, the total distance of relative scanning of the laser light when processing the workpiece on the substrate in the fifth step becomes the shortest.

According to a fourth aspect of the present invention, there is provided a processing method of processing a workpiece arranged along the two-dimensional direction on the substrate while relatively scanning the substrate with laser light. A first step of dividing a workpiece existing in the certain region into one or a plurality of blocks in each of the first direction and the second direction when processing the workpiece in the certain region; A second step of processing a workpiece in any one of the blocks after the block division; after the processing of the second step, the block closest to the position is the first candidate, and the second closest block is the block. Of the blocks of the first and second candidates, the block having the shorter distance from that position to the processing end position of the block is selected as the second candidate, and the workpiece in the block is processed. Process;
Thereafter, every time the machining of the workpiece in each block is completed, the machining end position of the previous block of the first and second candidates is processed to the machining end position of the block in the same manner as the third step. A fourth step of sequentially selecting blocks having shorter distances and processing the workpiece in the blocks.

According to this, as in the case of the first aspect of the invention, when the blocks having the closest relative scanning distance of the laser beam when processing the workpiece on the substrate are sequentially processed, The length is shorter than that in comparison, and the throughput is improved accordingly. In this case, processing of blocks, determination of blocks to be processed next, and processing of blocks are performed alternately.

According to a fifth aspect of the present invention, in the processing method according to the fourth aspect, when a block to be processed next is selected in the third step and the fourth step, the workpiece in the block is selected. Is determined so that the entire distance from the processing end position of the block before the block to the processing start position of the block to be processed next to the block becomes shorter.

According to this, as in the case of the second aspect of the invention, since the processing order in the processing blocks can be changed depending on the situation, the relative scanning distance of the laser beam between the processing blocks can be shortened.

[0016]

【Example】

<< First Embodiment >> A first embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a schematic configuration of a laser processing apparatus (laser repair apparatus) 10 according to a first embodiment for carrying out the processing method according to the present invention. The laser processing apparatus 10 includes an XY stage 12 that moves in a two-dimensional direction in a horizontal plane (reference plane) orthogonal to the paper surface of FIG. 1, and a Z stage 14 provided on the XY stage 12.
An irradiation optical system (which will be described later) that irradiates a laser beam for processing on a wafer W as a substrate placed on the Z stage 14 and an optical system for observing a processed portion (which will be described later). Laser interferometer 16 for detecting the movement position of the XY stage 12, and the XY stage 1
2 and a main controller 18 for controlling the laser light emission timing and the like.

The irradiation optical system is a light quantity adjusting section 2 for adjusting the quantity of the laser light L1 emitted from the laser light source 20.
2 and the laser light L1 that has passed through the light quantity adjusting unit 22
Beam splitter 24 that reflects toward the Y stage 12
And the laser light L reflected by the beam splitter 24
1. The objective lens 26, whose optical axis is arranged in a state of being orthogonal to the reference plane, is formed in the forward direction of 1.

The observation optical system includes a half mirror 30 for reflecting the observation illumination light L2 from the illumination light source 28 toward the objective lens 26, and the observation illumination light L2 having the same optical axis as the laser light L1. The objective lens 26 for irradiating the wafer W with the CCD camera 32 for receiving the reflected light from the wafer W through the objective lens 26, the beam splitter 24 and the half mirror 30 and the CCD camera 32 placed at a position conjugate with the surface of the wafer W. It is composed of. This CCD camera 32
A television monitor 34 is installed side by side.

According to this observation optical system, the illumination light L2
After being reflected by the half mirror 30, the objective lens 26
Thus, the wafer W is irradiated with the same optical axis as the laser light L1. The illumination light L2 applied to the wafer W is reflected by the wafer W, the reflected light is detected by the CCD camera 32, and the processing state can be observed by the television monitor 34.

The XY stage 12 is driven by a drive system 36 including a motor (not shown), and the drive system 36 is controlled by the main controller 18. The drive system 36 is
The drive system for the X drive of the XY stage, the drive system for the Y drive, and the drive system of the Z stage 14 are representatively shown.
Therefore, the Z stage 14 is also driven by the drive system 36 along the optical axis direction of the objective lens 26.

The main controller 18 is composed of a microcomputer or a minicomputer, and the main controller 18 monitors the measurement value of the laser interferometer 16 and monitors the processing points stored in an internal memory (not shown). While positioning the XY stage 12 on the optical axis of the objective lens 26 via the drive system 36 according to the data and a predetermined procedure,
By controlling the emission timing of the laser light of the laser light source 20, a fuse group as a workpiece arranged in the XY two-dimensional directions on the wafer is processed. Here, in practice, the X-axis laser interferometers 16X and Y
Although there is a laser interferometer 16Y for axes, these are typically shown as the laser interferometer 16 in FIG.

Next, the processing method by the laser processing apparatus 10 of the present embodiment will be described with reference to the flowchart of FIG. 2 showing the main control algorithm of the CPU in the main controller 18.

In step 100, the fuse group on the wafer is divided into blocks based on the processing data stored in the internal memory (not shown). Thereby, for example, in FIG.
A fuse group in a chip as shown in FIG.
Blocks are divided into 6 blocks, that is, a processing block A to a processing block F as shown in FIG. 6B, and information of this block division is stored in the internal memory.

At the next step 102, an arbitrary block is determined as a processing block (first processing block) to be processed first by a predetermined method, and the result is stored in the internal memory. The determination of this first processing block is, for example,
The block closest to the machining end position of the previous chip is determined as the first block. Thereby, for example, in FIG.
The processing block A of (B) is determined as the first processing block.

At the next step 104, the counter (not shown) is incremented by 1. This counter is reset (n ← 0) at the start stage of this control algorithm.

At the next step 106, the coordinates of the machining end position of the n-th machining block (first machining block at first) are obtained. Specifically, the processed data in the internal memory and step 102 (or step 112 described later,
114 and step 116) based on the information stored in the internal memory. As a result, for example, in FIG.
The coordinate position of a ′ in (A) is obtained.

In the next step 108, the machining block closest to the machining end position of the n-th machining block obtained in step 106 is selected as the first candidate, and the machining block closest to the second is selected as the second candidate. This allows, for example,
In the example of FIG. 3, the processing block B is selected as the first candidate, and the processing block E is selected as the second candidate.

In the next step 110, n calculated in step 106 from the machining end position of the first candidate machining block.
It is determined whether or not the distance L ₁ to the machining end position of the second machining block is equal to or less than the distance L ₂ from the machining end position of the second candidate machining block to the machining end position of the nth machining block. And if this decision is positive,
In step 112, the first candidate processed block is determined as the next candidate, that is, the (n + 1) th processed block to be processed. On the other hand, if the determination in step 110 is negative, the process proceeds to step 114 and the second candidate processed block is determined as the next candidate. For example, in the example of FIG. 3, the distance L ₁ = [a′−b ′]> distance L ₂ = [a′−
e ′], the determination at step 110 is denied,
In step 114, block E is determined as the next candidate.

In the next step 116, step 112
Alternatively, the processing direction of the processing block determined as the next candidate in 114 (that is, the processing order of the fuses in the block) is determined. This determination is made after the processing of the next candidate is completed from the processing end position of the n-th processing block, and then the next candidate (specifically, the second candidate when the first candidate is determined as the next candidate,
When the second candidate is determined as the next candidate, the processing direction is determined such that the total distance to the processing start position of the first candidate) becomes shorter. Specifically, using the example of FIG. 3, [a'-e
Since -e'-b]>[a'-e'-e-b], the processing direction of e '→ e is determined as the processing direction of the block E as the next candidate.

At the next step 118, it is judged whether or not the count value n of the counter reaches the total number N of blocks (N = 6 in the example of FIG. 3) divided into blocks at step 100, and this judgment is denied. If so, the process returns to step 104 to repeat the above-described processing / judgment. In this way, when the determination of the processing order of all the processing blocks is completed and the determination in step 118 is affirmed, the drive system 36 is operated in accordance with the processing order determined by the processing of steps 100 to 118. While the XY stage 12 is driven in the two-dimensional direction to sequentially position the processing points on the optical axis of the objective lens, the irradiation timing of the laser light source is controlled to perform the processing, and after the processing of the final processing block is completed, this routine is executed. Then, the series of processing of is ended. After that, the processing of the fuse group in the next chip is performed in the same manner as above.

FIG. 4 shows a processing route when the fuse group of FIG. 3 is processed by the above method. According to FIG. 4, machining is performed in the order of A → E → B → D → F → C. As is clear from comparison with the case of the conventional example of FIG. Since there is no part to return to, the processing capacity can be improved.

Further, regarding the processing direction in the block (processing order of the fuse rows in the block), the processing block A
When the processing block E is selected as the next candidate of
-E-e'-b]>[a'-e'-e-b], the machining block E is machined in the order of e '→ e, so the moving distance between the machining blocks is short. Therefore, the processing capacity can be further improved.

As described above, according to the first embodiment, the processing blocks scattered can be processed efficiently, and the moving distance of the XY stage 12 for processing can be shortened, and the throughput can be improved. There is. Also,
In the first embodiment, the processing order of the blocks is determined prior to the processing of the fuse group in the chip, so that the processing order of the next chip can be determined in parallel while processing one chip. By doing so, it is possible to further improve the throughput.

<< Second Embodiment >> Next, a second embodiment of the present invention will be described with reference to FIG. The second embodiment is different from the first embodiment only in the control algorithm of the CPU in the control device 18, and the device configuration and the like are the same as those in the first embodiment.
The description thereof will be omitted, and here, the processing method will be described with reference to the main controller 1.
This will be described with reference to the flowchart of FIG.

In steps 200 to 204, the same processing as steps 100 to 104 in the first embodiment is performed. In the next step 206, the nth machining block (first,
The first processing block) is processed. Specifically, based on the processed data in the internal memory and the information stored in the internal memory in step 202 (or steps 212, 214 and 216 described later), the drive system 36
The XY stage 12 is driven in the two-dimensional direction via the to position the processing points on the optical axis of the objective lens in sequence, and the irradiation timing of the laser light of the laser light source 20 is controlled, whereby the n-th processing block The fuse row is processed.

In the next step 208, the machining block closest to the current position (the machining end position of the n-th machining block) is set as the first candidate, and the machining block closest to the second is the second candidate.
Select as a candidate.

In the next step 210, is the distance L ₁ from the machining end position of the first candidate machining block to the current position less than or equal to the distance L ₂ from the machining end position of the second candidate machining block to the current position? Determine whether or not. If this determination is affirmative, the routine proceeds to step 212, where the first candidate machining block is determined as the next candidate, that is, the (n + 1) th machining block. On the other hand, if the determination in step 210 is negative, step 2
Proceeding to 14, the second candidate processed block is determined as the next candidate.

At the next step 216, similarly to step 116 of the first embodiment, step 212 or 214 is executed.
The machining direction of the machining block determined as the next candidate in (
The processing order of the fuses in the block is determined.

In the next step 218, it is judged whether or not the count value n of the counter reaches the total number N of blocks divided into blocks in step 200. If the judgment is negative, the process returns to step 204, The above processing and judgment are repeated. In this way, when the processing of all the processing blocks is completed and the determination in step 218 is affirmed, the series of processing of this routine is ended.

Also in this second embodiment, the fuse group of FIG. 3 is processed in the processing order shown in FIG. Therefore,
An effect equivalent to that of the first embodiment can be obtained.

In the above first and second embodiments, when the machining block of the next candidate is determined, the movement distance is also shortened in the machining direction of the block. Step 116 in the embodiment and step 216 in the second embodiment can be omitted. In this case, in the example of FIG.
The processing is performed in the order of [a → a ′] → E [e → e ′] → [b → b ′] ... However, even in such a case, FIG.
Compared with the conventional example, the total movement distance of the XY stage 12 is shorter and the throughput can be improved. Further, in the above-mentioned first and second embodiments, the case in which the machining direction in the block is determined so that the movement distance becomes shorter in step 116 or step 216 is illustrated for all the machining blocks determined as the next candidates. However, this is to minimize the total movement distance of the XY stage 12 from the processing start to the processing end of the fuse group in the chip,
This is the case, and the machining direction within a block may be determined for only some of the machining blocks.

Further, in the above embodiment, the case where the laser irradiation optical system including the objective lens 26 is fixed and the wafer W moves in the two-dimensional direction is illustrated, but the present invention is not limited to this. The wafer W may be fixed and the objective lens 26 may be moved in a two-dimensional direction.
In short, it suffices that the laser beam can be scanned relative to the wafer.

The processing method according to the present invention is a laser
It seems that it can be suitably applied to a laser processing device such as a marker (character information embedding machine).

[0045]

As described above, according to the present invention,
The relative scanning distance of the laser light to the substrate can be shortened, and even when the processing blocks are scattered on the substrate, the processing can be efficiently performed, and thus the throughput can be improved. There is no excellent effect.

[Brief description of drawings]

FIG. 1 is a diagram showing a schematic configuration of a laser processing apparatus according to a first embodiment for carrying out a processing method of the present invention.

FIG. 2 is a flowchart showing a main control algorithm of a CPU in a main control device of the first embodiment.

3A is a diagram showing an example of arrangement of fuse groups on a wafer, and FIG. 3B is a diagram showing results of dividing the fuse groups of FIG.

FIG. 4 is a diagram for explaining the effect of the first embodiment, and is a diagram showing a processing route when the fuse group of FIG. 3 is processed by the processing method according to the present invention.

FIG. 5 is a flowchart showing a main control algorithm of a CPU in a main control device of the second embodiment.

FIG. 6 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

 10 Laser Processing Device 18 Main Controller W Wafer (Substrate) AF Block (Block of Workpiece)

Claims (5)

[Claims] 1. A processing method for processing a workpiece arranged along a two-dimensional direction on the substrate while relatively scanning the substrate with a laser beam, wherein the workpiece within a certain region on the substrate is processed. Prior to processing the object,
A first step of dividing a workpiece existing in the certain region into one or a plurality of blocks in each of a first direction and a second direction; and selecting any one block after the block division And a second step of determining the block as a first machining block to be machined first; a block closest to a machining end position on the assumption that machining of a workpiece in the first machining block is completed. Is the first candidate and the second closest block is the second candidate, and one of these first and second candidate blocks that has a shorter distance from the machining end position of the first machining block to the machining end position of the block. Of the first and second candidates from the third processing block to the final processing block are determined as the second processing block to be processed second. A fourth step in which the shorter distance from the machining end position of the block to the machining end position of the block is determined as the next machining block; thereafter, according to the machining order determined in the second to fourth steps. A fifth step of processing a workpiece on the substrate. 2. The processing order of the workpieces in at least one block, the processing order of which has been determined in the third step and the fourth step, is set from the processing end position of the block before the block to that of the block. The processing method according to claim 1, wherein the processing is determined such that the entire distance of the block to be processed to the processing start position is shortened. 3. The machining order of the workpieces in all the blocks whose machining order is determined in the third step and the fourth step is processed from the machining end position of the block before the block to the next of the block. The processing method according to claim 2, wherein the entire distance to the processing start position of the block is determined so as to be short. 4. A processing method for processing a workpiece arranged along the two-dimensional direction on the substrate while relatively scanning the substrate with a laser beam, wherein the workpiece within a region on the substrate is processed. A first step of dividing a workpiece existing in the certain region into one or a plurality of blocks in each of a first direction and a second direction when processing the object; A second step of processing a workpiece in one block; and the second step
After processing the process, the block closest to that position is first
The candidate, the block closest to the second is set as the second candidate, and the block having the shorter distance from that position to the processing end position of the block is selected from the blocks of the first and second candidates, and the block in the block is selected. A third step of processing the work piece;
Thereafter, every time the machining of the workpiece in each block is completed, the machining end position of the previous block of the first and second candidates is processed to the machining end position of the block in the same manner as the third step. And a fourth step of sequentially selecting blocks having shorter distances and processing a workpiece in the blocks. 5. When a block to be processed next is selected in the third step and the fourth step, the processing order of the workpieces in the block is changed from the processing end position of the block before the block to the processing end position. The processing method according to claim 4, wherein the entire distance to the processing start position of the block to be processed next to the block is determined to be short.