JPS62193124A - Pattern position aligning method - Google Patents

Abstract

PURPOSE:To shorten an adjusting time; by providing a target center of each target mark on the extend line of a scribe line from the center in the longitudinal direction between elements, providing manual alignment marks on the extended lines from chip centers, and performing offset adjustment. CONSTITUTION:Target centers TC of target marks 4 in key patterns 1 and 2 are alignment with scribe centers SC. Manual alignment marks 3...3 are provided at a blank part of each element pattern 5 or on scribe lines 6 in the lateral direction on the extended parts from neighboring chip centers C. When, a pair of objective lenses are moved to the inside from the target centers TC, by (l) the manual alignment mark 3 at the chip center C of each element pattern 5 on the right side is observed on the side of the key pattern 1, and the manual alignment mark 3 at the chip center C of each element pattern 5 on the left side on the side of the key pattern 2 is observed. When the lenses are moved to the outside from the target centers TC by (l), the manual alignment marks 3...3 on the opposite side can be simultaneously observed. Thus the offset adjusting time can be shortened.

Description

DETAILED DESCRIPTION OF THE INVENTION (A) Field of Industrial Application The present invention relates to a pattern alignment method, and more particularly to a pattern alignment method when manufacturing a semiconductor device using a pair of objective lenses.

(b) Conventional technology The degree of integration of semiconductor devices is increasing year by year, and patterns are becoming increasingly finer. Accordingly, changes are occurring in semiconductor device manufacturing equipment, and optical phosphorography technology is also shifting from a contact exposure method to a reflective projection exposure method.

Specifically, as for exposure technology, the latest LS
As described in I Process Technology, pages 261 to 264, contact exposure method, proximity exposure method, reflective projection method, and reduction projection exposure method are known, and 1:1 exposure method and 5. It can be broadly divided into reduction exposure methods such as :1 or 10:1.

In the contact exposure method, proximity exposure method, or reflection projection method that uses a 1:1 exposure method, the third
As shown in the figure and FIG. 4, a pair of key patterns (11) and (12) are provided on the left and right sides of the mask, and a manual alignment mark (13) is provided on each element, respectively. FIG. 3 is a top view showing the positions where the key patterns (11) and (12) are provided.
1) (12) is provided. FIG. 4 is an enlarged view of the left and right key patterns (11) (12) in FIG. 3 and the respective element patterns (14) . . . <14) around them. Normally, the key patterns (11) and (12) occupy one element pattern (14) and are formed by a target mark in the shape of a square. Each element pattern (14)... (14) includes a pattern (not shown) necessary for forming each element and a manual alignment mark (13) on the blank area inside the pattern such as the periphery or on the scribe line. It is provided.

In the conventional exposure method, the mask and wafer are automatically aligned using a mask alignment device using key patterns (11) and (12), and then each manual alignment mark (13) is aligned using an objective lens. After adjusting the offset using a photolithography system, each element pattern is printed by exposure. This offset adjustment is to manually correct errors between the key patterns (11) and (12) and each element pattern that occur when creating a mask, and errors due to distortion of the wafer that occurs during manufacturing.

(C) Problems to be Solved by the Invention However, in the conventional exposure method, the manual alignment mark (13) is placed on the extension of the target center TC, which is the apex of the key patterns (11) and (12). It was set up like this. This is because fine adjustment is performed by simultaneously viewing the left and right manual alignment marks (13) using a pair of objective lenses during offset adjustment. This is because the pair of objective lenses has a mechanism that moves the same distance inward or the same distance outward, so that when positioned on the target center TC, the left and right manual alignment marks (13) can be captured simultaneously.

However, fixing the position of the manual alignment mark (13) has the disadvantage that the degree of freedom in pattern design is extremely lost. If the positions of the manual alignment marks (13) are different to avoid this, it will not be possible to view the left and right manual alignment marks (13) at the same time with a pair of objective lenses during offset adjustment, and it will take a lot of time to adjust the offset. In addition, there was a drawback that alignment accuracy was also lowered.

(d) Means for Solving the Problems The present invention has been made in view of the above-mentioned drawbacks, and the target mark of the key pattern is provided on the extension of the scribe center of the scribe line, and the target mark of the key pattern is provided in a similar manner to the extension of the scribe center of the scribe line. Since the manual alignment mark is provided on the extension of the chip center, the manual alignment mark can be set at a position other than the extension of the conventional target center, thereby providing a pattern alignment method that allows freedom in pattern design.

(e) Function According to the present invention, since the manual alignment mark is provided on the extension of the chip center C, the pair of objective lenses are automatically aligned using the key pattern using the mask alignment device. You can see the manual alignment mark at the same time when moving left or right, making it easy to make offset adjustments.

(f) Example A pattern alignment method according to the present invention will be described in detail with reference to FIGS. 1 and 2.

The left and right patterns shown in Figure 1 are key patterns (1>(2)
and an enlarged view of each element pattern (not shown) around it.

The alignment mark according to the present invention is a key pattern (1)
It consists of (2) and manual alignment mark (3). Key patterns (1) and (2) are provided spaced apart on the left and right, as shown in Figure 2, and each key pattern D)
(2) is formed so as to occupy usually two portions of the element pattern (5). The shape of the key pattern (1) (2> is formed by a V-shaped target mark (4), and a V-shaped mark on the wafer is placed in the middle of two sets of parallel V-shaped marks provided on the mask side. Align the key patterns (1) and (2) by setting the target mark (4) to 1 in Figure 1.
Although there are only seeds, there are multiple types of target marks (4), and the dashed line connecting the vertices of the target marks (4) is called a target center TC. Therefore, each target mark (4) has a different target center TC.

Manual alignment marks (3)...(3) are provided for each element pattern (5), and are formed by providing instruction marks corresponding to various process steps such as diffusion and etching within a square or rectangular frame. be done.

The feature of the present invention lies in the positional relationship between the key patterns (1) and (2) and the manual alignment marks (3)...(3). In other words, target center TC of target mark (4) of key patterns (1) and (2) is moved to scribe center S.
Align it with C and mark the manual alignment mark (3).
...(3) is provided on the margin of each element pattern (5) or on the adjacent horizontal scribe line (6) on the extension of each chip center C. Target mark (4
) matches the target center TC with the scribe center SC, so the key patterns (1) and (2) are formed using two of each adjacent element pattern (5).

Therefore, if the lateral size of the chip is 22, each manual alignment mark (3)...(3) will be formed on each element pattern (5) at a distance of P to the left and right from the target center TC. . Note that the triangular manual alignment marks (7)...(7) provided on the extension of the target center TC are based on conventional rules, and in the present invention, either the present invention or the conventional alignment mark can be selected. It will be like that.

According to the present invention, when the pair of objective lenses is moved inward from the target center TC by 2, the chips of each element pattern (5) on the right side as shown by the arrow on the key pattern (1) side shown on the left side of FIG. The manual alignment mark (3) can be seen at the center C, and on the key pattern (2) side shown on the right side of Figure 1, the manual alignment mark at the chip center C of each element pattern (5) on the left side can be seen as shown by the arrow. (3) can be seen. Conversely, by moving the pair of objective lenses outward from the target center TC, the manual alignment marks (3) on the opposite side can be viewed simultaneously.

After that, by moving the pair of objective lenses inward or outward by the horizontal size 22 of each element pattern (5), the manual alignment marks (3)...(3) of each adjacent element pattern (5) can be aligned one after another. can be viewed simultaneously using a pair of objective lenses.

According to the present invention, after automatic alignment is performed mechanically using key patterns (1) and (2), offset adjustment is performed using a pair of objective lenses. This offset adjustment is performed from the target center TC, that is, from the scribe center SC.
Manual alignment marks (3) separated by...
- Perform (3) by moving the pair of objective lenses outward or inward, making sure to capture both fields of view at the same time.

(g) Effect of the invention According to the invention, manual alignment mark (3)
...Since <3) can be set other than on the extension of the conventional target center TC, manual alignment mark <3) ... The 11τ of <3) can be selected, greatly improving the degree of freedom in pattern design. can.

Next, in the present invention, manual alignment mark (3)
...Even if you change the position of (3), you can make the offset adjustment while looking at the left and right manual alignment marks 3)...(3) at the same time in both fields of view of the pair of objective lenses, just like before. Adjustment time can be shortened and alignment accuracy can be improved.

[Brief explanation of drawings]

FIG. 1 is a top view illustrating the pattern alignment method of the present invention, FIG. 2 is a top view illustrating the position of the key pattern used in the present invention, and FIG. 3 is a top view illustrating the position of the conventional key pattern. 4 are top views illustrating a conventional pattern positioning method. (1) (2) are key patterns, (3)... (3) are manual alignment marks, (4) are target marks, (5) are each element pattern, (6) are scribe lines, TC is target center , C is the chip center, SC
is the scribe center. Applicant: Sanyo Electric Co., Ltd. and 1 other representative: Shizuo Sano, patent attorney Figure 1 Figure 2 Figure 4

Claims (1)

[Claims] (1) After performing automatic alignment using the key pattern using a mask that has a key pattern and manual alignment marks provided for each element, offset adjustment is performed using a pair of objective lenses using left and right manual alignment marks. In the pattern alignment method that performs
The target center of the target mark of the key pattern is provided on an extension of the center of the vertical scribe line between each element, the manual alignment mark is provided on an extension of the chip center of each element pattern, and the pair of objective lenses A pattern positioning method characterized in that offset adjustment is performed by looking at the manual alignment mark at the same time.