TWI494561B - Method of mapping coordinates for inspecting a wafer - Google Patents

Description

Method for detecting alignment coordinates of wafers

The present invention relates to a method of aligning coordinates, and more particularly to a method for detecting aligned coordinates of a wafer.

Conventionally, when an automatic optical inspection device (AOI) is used to detect a die of a wafer, the position of the mask die provided by the mask file is compared with the position of the blank die of the wafer. However, in the process before the wafer is inspected, it is inevitable that fragmentation or poor material feeding will occur, resulting in a large number of blank crystal grains of the wafer, so that the position of the mask crystal grains is compared with the position of the blank crystal grains of the wafer. failure.

Therefore, the technician needs to manually specify the position of the blank die in order to allow the problematic wafer (eg, a partially fragmented wafer) to continue to be subjected to subsequent processes after inspection. However, manually specifying the position of the blank die is prone to a specified error, which not only consumes a large amount of detection time, but also causes the yield to be difficult to increase.

One aspect of the present invention is a method for detecting alignment coordinates of a wafer.

According to an embodiment of the invention, a method for detecting a pair of coordinates of a wafer includes the steps of: (a) obtaining coordinates of a plurality of mask dies corresponding to the wafer. (b) Using the coordinates of the reticle die to calculate a plurality of first distances from either of the reticle dies to the other reticle dies. (c) Find a plurality of blank dies based on the location of the scanned wafer. (d) Comparing the blank dies and the reticle grains according to the first distance to obtain a plurality of alignment coincidence times. (e) When the highest match is generated, the coordinates of the blank die are obtained using the coordinates of the mask die. (f) Calculating a second distance between the coordinates of one of the blank dies and the reference coordinate. (g) adjusting the reference coordinates according to the second distance to correspond to the coordinates of the reticle die.

In an embodiment of the invention, the step (c) includes: obtaining a position data of the scan wafer from the spot test program.

In an embodiment of the invention, the step (d) includes moving the reticle die to the blank dies to overlap at least one of the reticle grains and one of the blank dies.

In an embodiment of the invention, the step (e) includes: sorting the matching times.

In an embodiment of the invention, the step (e) includes: recording a position state of the mask dies and the blank dies when the highest one of the matching times is generated.

In an embodiment of the invention, the step (c) comprises: scanning the wafer using an automatic optical detecting device.

In an embodiment of the invention, the step (g) comprises: moving the photosensitive element of the automatic optical detecting device to the origin die of the wafer according to the reference coordinate.

In an embodiment of the invention, the step (b) includes: recording a first distance from the reticle die to the other reticle die.

In an embodiment of the invention, in the above step (c), the number of blank dies is the same as the number of reticle grains.

In an embodiment of the invention, in the above step (e), the highest of the matching times is equal to the number of blank dies.

In the above embodiment of the present invention, since the coordinates of the reticle die can calculate the first distance from the reticle die to the other reticle die, the first distance can be used to compare the blank die and the mask crystal. The grain, when the highest match is produced, indicates that the blank die corresponds to the position of the mask die, so that the coordinates of the blank die can be obtained by the coordinates of the mask die. In this way, the second distance between the coordinates of the blank die and the reference coordinate can be calculated, and the reference coordinate can be adjusted according to the second distance to conform to the coordinates of the mask dies. The method for comparing coordinates of the present invention can obtain the coordinates of the blank crystal grains from the coordinates of the mask die, and can obtain the coordinates of the blank crystal grains in an automatic manner, so that the wafer can obtain the reference coordinates after the detection for subsequent processes. .

Therefore, the detection time can be saved and the yield of the wafer can be improved.

110‧‧‧ wafer

112a‧‧‧ Blank crystal

112b‧‧‧ blank grain

112c‧‧‧ blank grain

112d‧‧‧ blank grain

120‧‧‧Photomask

122a‧‧‧Photomask grain

122b‧‧‧Photomask grain

122c‧‧‧mask grain

122d‧‧‧Photomask grain

132‧‧‧Reference coordinates

D1‧‧‧Second distance

D2‧‧‧Second distance

D3‧‧‧Second distance

D4‧‧‧Second distance

D1~d12‧‧‧first distance

S1‧‧‧ steps

S2‧‧‧ steps

S3‧‧‧ steps

S4‧‧‧ steps

S5‧‧ steps

S6‧‧ steps

S7‧‧ steps

FIG. 1 illustrates a method of comparing coordinates according to an embodiment of the present invention Flow chart.

2 is a top plan view of a wafer in accordance with an embodiment of the present invention.

3 is a top plan view of a reticle in accordance with an embodiment of the present invention.

Figure 4 is a schematic diagram showing the first distance from one of the reticle dies of Figure 3 to the other reticle dies.

Figure 5 is a schematic illustration of the first distance from the other of the reticle dies of Figure 3 to the other reticle dies.

Figure 6 is a schematic view showing the first distance from the reticle of the reticle of Figure 3 to the other reticle dies.

FIG. 7 is a schematic view showing a case where the blank crystal grains of FIG. 2 are aligned with the photomask crystal grains of FIG. 3.

FIG. 8 is a schematic view showing a case where the blank crystal grains of FIG. 2 are aligned with the photomask crystal grains of FIG. 3.

FIG. 9 is a schematic view showing a case where the blank crystal grains of FIG. 2 are aligned with the photomask crystal grains of FIG. 3.

Figure 10 is a schematic diagram showing the calculation of the second distance between the blank die and the reference coordinate of Figure 9.

The embodiments of the present invention are disclosed in the following drawings, and the details of However, it should be understood that these practical details are not intended to limit the invention. That is, in some embodiments of the invention, these practical details are not necessary. In addition, some of the conventions used to simplify the schema The structures and elements used in the drawings will be illustrated in a simplified schematic manner.

1 is a flow chart showing a method of comparing coordinates according to an embodiment of the present invention. As shown in the figure, the method for detecting the alignment coordinates of the wafer includes the following steps: First, in step S1, coordinates of a plurality of mask dies corresponding to the wafer are obtained. Next, in step S2, a plurality of first distances from the reticle die to the other reticle dies are calculated using the coordinates of the reticle die. Then in step S3, a plurality of blank dies are found based on the position information of the scanned wafer. Next, in step S4, the blank die and the mask die are compared according to the first distance to obtain a plurality of alignment match times. Then, in step S5, when the highest match is generated, the coordinates of the blank die are obtained using the coordinates of the mask die. Next, in step S6, a second distance between the coordinates of one of the blank dies and the reference coordinate is calculated. Finally, in step S7, the reference coordinates are adjusted according to the second distance to correspond to (conform to) the coordinates of the reticle die. At present, some of the fragmented wafers cannot be automated because some fragments and complete films have doubts about the wrong points and must be manually confirmed. This technology can be overcome by the technique of the present invention to make all products (including intact pieces and fragments). Automated work.

In the following description, each of the above steps will be specifically described.

2 is a top plan view of a wafer 110 in accordance with an embodiment of the present invention. 3 is a top plan view of a reticle 120 in accordance with an embodiment of the present invention. Referring also to Figures 2 and 3, wafer 110 has a plurality of blank dies 112a, 112b, 112c, 112d. The blank grains 112a, 112b, 112c, 112d may be, for example, a void region or a fragment region. The mask 120 has a plurality of mask dies 122a, 122b, 122c, 122d. In the first step, step S1 The coordinates of the mask dies 122a, 122b, 122c, and 122d corresponding to the mask 120 of the wafer 110 may be obtained first. The coordinates of the reticle dies 122a, 122b, 122c, and 122d may be obtained by the reticle file provided by the wafer 110 manufacturer or by the spot measurement file of the wafer 110.

Next, in step S2 of Fig. 1, a plurality of first distances d1, d2, d3 of the mask die 122a to the other mask dies 122b, 122c, 122d can be calculated using the coordinates of the mask die 122a. The first distance d1 is the distance between the reticle die 122a and the reticle die 122b. The first distance d2 is the distance between the reticle die 122a and the reticle die 122c. The first distance d3 is light. The distance between the mask die 122a and the mask die 122d.

4 is a schematic view showing the first distances d4, d5, and d6 of the reticle die 122b of FIG. 3 to the other reticle dies 122a, 122c, and 122d. Similarly, a plurality of first distances d4, d5, d6 of the reticle die 122b to the other reticle dies 122a, 122c, 122d can be calculated using the coordinates of the reticle die 122b. The first distance d4 is the distance between the reticle die 122b and the reticle die 122a. The first distance d5 is the distance between the reticle die 122b and the reticle die 122c. The first distance d6 is light. The distance between the mask die 122b and the mask die 122d.

FIG. 5 is a schematic view showing the first distances d7, d8, and d9 of the reticle die 122c of FIG. 3 to the other reticle dies 122a, 122b, and 122d. Similarly, a plurality of first distances d7, d8, d9 of the reticle die 122c to the other reticle dies 122a, 122b, 122d can be calculated using the coordinates of the reticle die 122c. The first distance d7 is the distance between the reticle die 122c and the reticle die 122a, and the first distance d8 is the reticle die 122c and the mask crystal. The distance between the particles 122b, the first distance d9 is the distance between the mask die 122c and the mask die 122d.

FIG. 6 is a schematic diagram showing the first distances d10, d11, and d12 of the reticle die 122d of FIG. 3 to the other reticle dies 122a, 122b, and 122c. Similarly, a plurality of first distances d10, d11, d12 of the reticle die 122d to the other reticle dies 122a, 122b, 122c can be calculated using the coordinates of the reticle die 122d. The first distance d10 is the distance between the reticle die 122d and the reticle die 122a. The first distance d11 is the distance between the reticle die 122d and the reticle die 122b. The first distance d12 is light. The distance between the mask die 122d and the mask die 122c.

The first distances d1 to d12 shown in Figures 3 to 6 can be recorded.

Referring to FIG. 2, then in step S3 of FIG. 1, blank crystal grains 112a, 112b, 112c, and 112d can be found based on the positional data of the scanning wafer 110. In this step, the wafer 110 can be scanned using an Automated Optical Inspection (AOI), and the position data of the scan wafer 110 can be obtained from the spot test program. In the present embodiment, the number of the blank dies 112a, 112b, 112c, and 112d of the wafer 110 is the same as the number of the reticle dies 122a, 122b, 122c, and 122d of the reticle 120 of FIG. However, it is not intended to limit the invention.

FIG. 7 is a schematic view showing the blank crystal grains 112a, 112b, 112c, and 112d of FIG. 2 aligned with the mask crystal grains 122a, 122b, 122c, and 122d of FIG. Then, in step S4 of FIG. 1, the blank crystal grains 112a, 112b, 112c, 112d and the mask crystal grains can be aligned according to the first distances d1 to d12. 122a, 122b, 122c, 122d to obtain a plurality of alignment matches. When the blank dies 112a, 112b, 112c, 112d and the reticle dies 122a, 122b, 122c, 122d are aligned, the reticle dies 122a, 122b, 122c, 122d can be moved to the blank dies 112a, 112b, 112c, 112d, at least one of the mask dies 122a, 122b, 122c, 122d is overlapped with one of the blank dies 112a, 112b, 112c, 112d.

In the present embodiment, the mask crystal grains 122d overlap the blank crystal grains 112a, and the remaining mask crystal grains 122a, 122b, and 122c are not overlapped with the blank crystal grains 112b, 112c, and 112d, and therefore the number of coincidences is 1.

FIG. 8 is a schematic view showing the blank crystal grains 112a, 112b, 112c, and 112d of FIG. 2 aligned with the mask crystal grains 122a, 122b, 122c, and 122d of FIG. In the present embodiment, the mask die 122b overlaps the blank die 112a, and the mask die 122d overlaps the blank die 112c. The remaining mask dies 122a, 122c are not overlapped with the blank dies 112b, 112d, so the alignment match is two.

FIG. 9 is a schematic view showing the blank crystal grains 112a, 112b, 112c, and 112d of FIG. 2 aligned with the mask crystal grains 122a, 122b, 122c, and 122d of FIG. In the present embodiment, the mask die 122a overlaps the blank die 112a, the mask die 122b overlaps the blank die 112b, the mask die 122c overlaps the blank die 112c, and the mask die 122d and the blank The crystal grains 112d overlap. Therefore, the match count is 4.

Since the number of blank dies 112a, 112b, 112c, 112d and the number of reticle dies 122a, 122b, 122c, 122d of the reticle 120 are both four, the number of coincidences may be included once (as shown in Fig. 7). Shown), 2 Conditions (as shown in Figure 8) and 4 times (as shown in Figure 9), and these conditions can be sorted. In step S5 of the first step, when the highest one of the matching coincidence times is generated, the coordinates of the blank crystal grains 112a, 112b, 112c, and 112d can be obtained by the coordinates of the mask crystal grains 122a, 122b, 122c, and 122d. The positional state of the mask dies 122a, 122b, 122c, 122d and the blank dies 112a, 112b, 112c, 112d at the time of the highest number of coincidences is recorded. When the highest match is generated, it indicates that the blank dies 112a, 112b, 112c, 112d correspond to the positions of the reticle dies 122a, 122b, 122c, 122d. In the present embodiment, the highest match ratio is 4, which is equal to the number of blank dies 112a, 112b, 112c, 112d.

FIG. 10 is a schematic diagram showing the calculation of the second distances D1, D2, D3, and D4 between the blank crystal grains 112a, 112b, 112c, and 112d and the reference coordinates 132 in FIG. After the coordinates of the blank dies 112a, 112b, 112c, and 112d are obtained, in the first step S6, the second distance D1 between the coordinates of the blank dies 112a and the reference coordinates 132 of the wafer 110 can be calculated. A second distance D2 between the coordinates of the die 112b and the reference coordinate 132 of the wafer 110, a second distance D3 between the coordinates of the blank die 112c and the reference coordinate 132 of the wafer 110, and the coordinates of the blank die 112d are calculated. A second distance D4 between the reference coordinates 132 of the wafer 110.

Finally, in step S7 of FIG. 1, the reference coordinates 132 can be adjusted according to the second distances D1, D2, D3, and D4 to correspond to (conform) the coordinates of the mask dies 122a, 122b, 122c, and 122d, and specify the reference coordinates. 132 is the origin grain. In this way, the photosensitive element of the automatic optical detecting device can move to the origin die of the wafer 110 according to the reference coordinate 132.

The method for detecting the coordinate of the wafer is compared with the prior art. Since the coordinates of the reticle die can calculate the first distance from the reticle die to the other reticle die, the first The distance can be used to compare the blank die and the mask die. When the highest match is generated, it indicates that the blank die corresponds to the position of the mask die, so the blank crystal can be obtained by using the coordinates of the mask die. The coordinates of the grain. In this way, the second distance between the coordinates of the blank die and the reference coordinate can be calculated, and the reference coordinate can be adjusted according to the second distance to conform to the coordinates of the mask dies. The method of comparing the coordinates can obtain the coordinates of the blank die from the coordinates of the mask die, and the coordinates of the blank die can be obtained by automated operation, so that the reference mark can be obtained after the wafer is used for subsequent processes. Therefore, the detection time can be saved and the yield of the wafer can be improved.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and the present invention can be modified and modified without departing from the spirit and scope of the present invention. The scope is subject to the definition of the scope of the patent application attached.

S1‧‧‧ steps

S2‧‧‧ steps

S3‧‧‧ steps

S4‧‧‧ steps

S5‧‧ steps

S6‧‧ steps

S7‧‧ steps

Claims (10)

A method for detecting alignment coordinates of a wafer, comprising the steps of: (a) obtaining coordinates of a plurality of reticle grains corresponding to a wafer; and (b) calculating coordinates of the reticle grains a plurality of first distances from the mask die to the other of the mask dies; (c) finding a plurality of blank dies according to the position of the wafer; (d) according to the first Comparing the blank dies with the reticle dies to obtain a plurality of alignment matches; (e) utilizing the coordinates of the reticle grains when the highest number of alignment matches is generated Obtaining coordinates of the blank crystal grains; (f) calculating a second distance between a coordinate of one of the blank crystal grains and a reference coordinate; and (g) adjusting the reference coordinate according to the second distance to conform to the The coordinates of the reticle grains. The method of claim 1, wherein the step (c) comprises: obtaining a location data of the wafer from the one-point test program. The method of claim 1, wherein the step (d) comprises: moving the mask dies to the blank dies, at least one of the reticle dies and one of the blank dies Overlapping. The method of claim 1, wherein the step (e) comprises: sorting the alignment matches. The method of claim 1, wherein the step (e) comprises: recording a position state of the mask dies and the blank dies when the highest one of the comparison matches is generated. The method of claim 1, wherein the step (c) comprises: scanning the wafer using an automated optical inspection device. The method of claim 6, wherein the step (g) comprises: moving a photosensitive element of the automatic optical detecting device to an origin die of the wafer according to the reference coordinate. The method of claim 1, wherein the step (b) comprises: recording the first distances of the reticle dies to other of the reticle dies. The method of claim 1, wherein in the step (c), the number of the blank dies is the same as the number of the reticle dies. The method of claim 1, wherein in the step (e), the The highest number of comparisons is equal to the number of blank dies.