JP2002090115A - Detecting device and detecting method for measurement mark, and manufacturing method of semiconductor device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detecting device and detecting method for measurement mark and a manufacturing method of semiconductor device capable of reduction in the image contrast of a measurement mark when reducing the height of a measurement mark by a treatment after the formation of the measurement mark in the formation of a laminated film on the measurement mark or when the layer or bed structure having the measurement mark formed thereon having a reflectivity or refractive index hardly detectable by a measuring device, and never causing deterioration of measurement precision or impossibleness of measurement even if the forming state of the measurement mark is not good. SOLUTION: The axial direction M of the sensor of this measurement mark detecting device is inclined at an angle (a) not conformed to the normal direction L of a wafer having the measurement mark to be measured provided thereon, so that the wafer can be set non-movably. The normal line L of the wafer may be inclined at an angle b not conformed to the axial direction M of the sensor of the detecting device, so that the senor can be set non-movably. Consequently, the image contrast of the measurement mark when inclined can be reinforced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a measurement mark detection device, a detection method, and a method for manufacturing a semiconductor device, and more particularly to a measurement mark for alignment positioning of an overlay device or an exposure device in a process of manufacturing an IC or LSI. The present invention relates to a measurement mark detection device, a detection method, and a method for manufacturing a semiconductor device.

[0002]

2. Description of the Related Art Various measurement devices in lithography,
For example, in a superposition apparatus or an exposure apparatus, a method for surely performing measurement is required, and it is essential to eliminate a measurement error due to miniaturization of a product pattern. Therefore, conventionally, a method of detecting a measurement mark used for alignment positioning or the like has been used in order to eliminate a measurement error such as an overlay accuracy or the like and increase the measurement accuracy. However, when the image contrast of the measurement mark is weak, there is a problem that a measurement error occurs or measurement becomes impossible. It is conceivable that the measurement mark has an optimum structure or shape for the measurement apparatus. However, since the measurement mark is formed incidentally in the process of manufacturing an IC or LSI, it is not usually performed.

[0005] Problems in the conventional method for detecting a measurement mark will be exemplified below. (1) Problems when a laminated film is formed on a measurement mark. FIG. 14 illustrates a conventional method for detecting a measurement mark. 14A and 14B, reference numeral 13 denotes a wafer, 10 denotes an interlayer film formed on the wafer 13, 12 denotes a measurement mark to be detected, 8 denotes a resist formed on the measurement mark 12, and the like. is there. FIG.
(A) shows the contrast of the measurement mark 12 and the like measured from the upper surface. FIG. 14B is a top view of FIG. 14A. In other words, FIG. 14A is a cross-sectional view taken along a straight line R1R2 in FIG.

[0004] As shown in FIG. 14A, after a measurement mark 12 is formed on a wafer 13 or the like, the measurement mark 12 is formed.
In many cases, a resist 8 or another laminated film (not shown) is formed thereon. In this case, since the measurement mark 12 is detected through the formed resist 8 or another laminated film, (a) the measurement mark 12 becomes difficult to see. (B) The cut pattern of the measurement mark 12 may be buried or thinned, and may be burned out. (C) The shape of the edge of the measurement mark 12 is deteriorated, and the measurement accuracy is reduced. As a result, there is a problem that the image contrast of the measurement mark 12 is reduced as shown by a dotted line in FIG. At an actual implementation level, it is difficult to change the structure of the measurement mark 12 according to the measurement device. Therefore, there is no effective countermeasure when forming the resist 12 or another laminated film on the measurement mark 12.

(2) Problems in the case where the height of the measurement mark decreases in the processing after the formation of the measurement mark. After forming the measurement mark, various etching processes or CM
When a flattening process such as P or etch back is performed, the height of the measurement mark decreases. As a result, various problems are directly caused to lower the image contrast of the measurement mark. Although it is conceivable to provide a dedicated process for forming a measurement mark, there is a problem that the manufacturing process is complicated.

(3) Problems in optical characteristics of measurement marks. The layer or the underlying structure on which the measurement mark is formed may have a reflectance or a refractive index that is difficult for the measurement device to detect. In this case, the image contrast of the measurement mark is reduced, and various problems occur. At the actual implementation level, it is difficult to change the structure of the measurement mark or the optical system of the measurement device in accordance with the measurement device, and there has been no effective countermeasure against the above-mentioned problem with the optical characteristics of the measurement mark.

(4) Problems related to the shape of the measurement mark. When the formation state of the measurement mark is not good, for example, when the shape, depth or height of the mark edge of the measurement mark varies, there is a problem that the measurement accuracy is reduced or the measurement becomes impossible. Become. At the actual implementation level, it is difficult to change the structure of the measurement mark according to the measurement device, and there has been no effective countermeasure against the above-mentioned problem with the shape of the measurement mark.

[0008]

As described above, (1)
When a laminated film is formed on the measurement mark, (2) when the height of the measurement mark is reduced by the processing after the formation of the measurement mark, or (3) when the layer or the base structure on which the measurement mark is formed is:
If the measurement device has a reflectance or a refractive index that is difficult to detect, there is a problem that the image contrast of the measurement mark is reduced. (4) When the formation state of the measurement mark is not good, there has been a problem that the measurement accuracy is reduced or the measurement becomes impossible.

Therefore, an object of the present invention is to solve the above-mentioned problem. (1) When a laminated film is formed on a measurement mark, (2) when a measurement mark is formed in a process after the formation of the measurement mark. (3) Prevent a decrease in the image contrast of the measurement mark even if the layer or the underlying structure on which the measurement mark is formed has a reflectance or a refractive index that is difficult to detect by the measurement device. And
(4) An object of the present invention is to provide a measurement mark detection device, a detection method, and a method of manufacturing a semiconductor device, which do not reduce measurement accuracy or make measurement impossible even when the formation state of a measurement mark is not good. .

[0010]

A measuring mark detecting device according to the present invention is a measuring mark detecting device for detecting a measuring mark provided on a wafer by a sensor, wherein the axial direction of the sensor is the same as that of the wafer. The wafer has a predetermined angle that does not coincide with the line direction, and the wafer is non-movably installed.

Here, in the measurement mark detection device according to the present invention, a predetermined angle which the axial direction of the sensor has with respect to the normal direction of the wafer can be variably set.

A measurement mark detection device according to the present invention is a measurement mark detection device for detecting a measurement mark provided on a wafer by a sensor, wherein a normal direction of the wafer does not coincide with an axial direction of the sensor. And the sensor is non-movably installed.

Here, in the measurement mark detecting device according to the present invention, a predetermined angle that a normal line direction of the wafer has with respect to an axial direction of the sensor can be variably set.

A measurement mark detection device according to the present invention is a measurement mark detection device for detecting a measurement mark provided on a wafer by a sensor, wherein an axial direction of the sensor does not coincide with a normal direction of the wafer. The normal direction of the wafer has a predetermined second angle that does not coincide with the axial direction of the sensor, and the predetermined first angle and the second angle can be set variably. There is something.

Here, in the measurement mark detection device of the present invention, the measurement mark can be used for overlay or alignment positioning in lithography.

A measurement mark detection method according to the present invention is a measurement mark detection method in which a measurement mark provided on a wafer is detected by a sensor, wherein a step of immovably installing the wafer provided with the measurement mark is provided. An angle setting step of setting the axial direction of the sensor to a predetermined angle that does not match the normal direction of the wafer, and a detection step of detecting a measurement mark at the angle set by the angle setting step. is there.

Here, in the measurement mark detecting method according to the present invention, after the detecting step, an angle that the axial direction of the sensor has with respect to a normal direction of the wafer is a predetermined angle set in the angle setting step. An angle resetting step of setting an angle to a symmetric angle with respect to the vertical, a redetection step of detecting a measurement mark at an angle set in the angle resetting step, and a result detected in the detection step and the redetection step. Correcting the result detected in the detection step by averaging the detected result.

A measurement mark detection method according to the present invention is a measurement mark detection method for detecting a measurement mark provided on a wafer by a sensor, wherein the sensor is immovably installed, and a normal line of the wafer is provided. The method includes an angle setting step of setting a direction to a predetermined angle that does not match the axial direction of the sensor, and a detection step of detecting a measurement mark at the angle set in the angle setting step.

Here, in the measurement mark detecting method according to the present invention, after the detecting step, an angle at which a normal line direction of the wafer faces the axial direction of the sensor is set to a predetermined angle set in the angle setting step. Angle resetting step of setting the angle of the angle to the symmetrical angle with respect to the vertical, a re-detecting step of detecting the measurement mark at the angle set in the angle resetting step, a result detected in the detecting step and the re-detecting step Correcting the result detected in the detection step by averaging the result detected in the detection step.

According to a seventh aspect of the present invention, there is provided a method for detecting a measurement mark, wherein the measurement mark provided on the wafer is detected by a sensor. The step of immovably installing the provided wafer, the angle setting step of setting the axial direction of the sensor to a predetermined angle that does not match the normal direction of the wafer, and the angle set by the angle setting step. A method of manufacturing a semiconductor device having a measurement mark detection method including a detection step of detecting a measurement mark.

[0021]

Embodiments of the present invention will be described below in detail with reference to the drawings.

Embodiment 1 FIG. 1 illustrates the principle of enhancing the image contrast of a measurement mark common to each embodiment of the present invention. 1A and 1B, reference numeral 13 denotes a wafer, 10 denotes an interlayer film formed on the wafer 13, 12 denotes a measurement mark to be detected, 8 denotes a resist formed on the measurement mark 12, and the like. is there. FIG. 1 (B)
Indicates the contrast of the measurement mark 12 and the like measured from the upper surface of FIG. FIG. 1B is a top view of FIG. 1A. In other words, FIG. 1A is a cross-sectional view taken along a straight line R1R2 in FIG.

In the conventional measurement mark detection method shown in FIG. 14A, the horizontal line and the straight line R of the wafer 13 are used.
Although the angle coincides with 1R2, in the detection method of the present invention shown in FIG. 1A, the normal M of the wafer 13 is inclined rightward by an angle r with respect to the normal L of the straight line R1R2. .
As shown in FIG. 1A, since the measurement mark 12 is a structure having a three-dimensional structure, the side wall 15 of the measurement mark 12 is aligned with the normal L and the axial direction by giving the inclination a. It is exposed to a measurement system (not shown) located above FIG. As a result, an effect can be obtained in which the image contrast is enhanced as indicated by a straight line in FIG. 1B, as compared with the conventional image contrast in the case of simple top surface measurement (FIG. 14B). . It is preferable that the angle r with respect to the normal L is 0 degree <r ≦ ± 45 degrees. However, the angle is not limited to the range of 0 degrees <r ≦ ± 45 degrees, and may be any angle at which the normal L and the normal M do not coincide.

FIG. 2 shows a measurement mark detection device according to the first embodiment of the present invention. In FIG. 2, portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and a description thereof will be omitted. 2A and 2B, reference numeral 11 denotes a sensor part of a measurement system (hereinafter, simply referred to as a “sensor”).
It is located above the measurement mark 12 along the normal L.

In FIG. 2A, the axial direction M of the sensor 11 and the normal L of the wafer 13 match, but in the first embodiment of the present invention, as shown in FIG. 11
Is tilted to the right by an angle a with respect to the normal L. Here, the wafer 13 is fixed (installed non-movably) while remaining horizontal in FIG. The angle may be set arbitrarily. For example, the angle between the surface direction of the wafer 13 fixed horizontally and the axial direction M of the sensor 11 may be set to a1.

FIG. 3 shows a case where the measurement mark 12 is detected from the sensor 11 located in the direction shown in FIG. In FIG. 3, portions denoted by the same reference numerals as those in FIGS. 1 (A) and 1 (B) indicate the same elements, and thus description thereof is omitted. In FIG. 3, reference numeral 32 denotes an image contrast of the measurement mark 12 detected by the sensor 11. FIG. 4 shows a case where the measurement mark 12 is detected from the sensor 11 located in the direction inclined rightward by the angle a shown in FIG. FIG. 4 and FIG.
Parts denoted by the same reference numerals as in (A) and (B) indicate the same elements, and a description thereof will be omitted. In FIG. 4, reference numeral 42 denotes an image contrast of the measurement mark 12 detected by the sensor 11.

Since the measurement mark 12 is a structure having a three-dimensional structure as described above, the side wall 15 of the measurement mark 12 is inclined by inclining the sensor 11 to the right by an angle a with respect to the normal L. It will be exposed to the sensor 11. As a result, it is possible to obtain an effect that the image contrast 42 of the measurement mark 12 when tilted is enhanced as compared with the detected image contrast 32 of the measurement mark 12 when tilted. It is preferable that the angle a satisfies 0 degree <a ≦ ± 45 degrees with respect to the normal L. But 0
The angle is not limited to the range of degree <a ≦ ± 45 degrees, and may be any angle at which the axial direction M of the sensor 11 and the normal L of the wafer 13 do not match. The angle a1 is preferably 45 degrees ≦ a1 ≦ 135 degrees (excluding a1 = 90 degrees) with respect to the plane direction of the horizontally fixed wafer 13. However, the angle is not limited to the range of 45 degrees ≦ a1 ≦ 135 degrees (excluding a1 = 90 degrees), and may be any angle as long as the axial direction M of the sensor 11 and the normal L of the wafer 13 do not match.

FIGS. 5A and 5B show a measuring method of a measuring mark and a measuring method including correction in the first embodiment of the present invention. In FIG. 5, portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and thus description thereof will be omitted.

As shown in FIG. 5A, first, a wafer 13 provided with a measurement mark 12 is non-movably installed. Next, the axial direction M of the sensor 11 is set to a predetermined angle that does not match the normal direction L of the wafer 13, for example, an angle a (angle setting step). The measurement mark 12 is detected at this angle a (detection step). The above is the method of measuring the measurement mark 12.

FIG. 5B shows a correction method for detecting the measurement mark 12 with higher accuracy. After detecting the measurement mark 12 at the angle a, as shown in FIG. 5B, the angle that the axial direction M of the sensor 11 has with respect to the normal direction L of the wafer 13 is perpendicular to the above angle (in this case, The angle is set to the symmetry angle −a with respect to the normal direction L) (angle resetting step). The measurement mark 12 is detected again at the symmetry angle -a (redetection step). Next, by averaging the result detected at the angle a and the result detected at the symmetric angle −a,
The result detected at the first angle a is corrected. As a result,
The measurement mark 12 can be detected with higher accuracy as compared with the case where measurement is performed only at the angle a.

FIG. 6 shows another correction method according to the first embodiment of the present invention. In FIG. 6, portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and a description thereof will be omitted.
In FIG. 6, reference symbol Xa denotes a sensor 11 tilted by an angle a.
, The apparent amount of displacement of the measurement mark when the measurement mark 12 is viewed from, Y is the distance between the measurement mark 12 and the sensor 11.

As shown in FIG. 6, the relationship between the apparent measurement mark shift amount Xa and the distance Y is as follows.

[0033]

(Equation 1) Can be requested. By matching the measurement mark deviation amount Xa obtained by the equation 1 with the result measured only at the angle a, the measurement mark 12 can be detected with higher accuracy as compared with the case where measurement is performed only at the angle a.

As described above, according to the first embodiment, the axial direction M of the sensor 11 of the measurement mark detecting device coincides with the normal direction L of the wafer 13 on which the measurement mark 12 to be measured is provided. The wafer 13 can be installed non-movably by inclining at an angle a. As a result, it is possible to obtain an effect that the image contrast 42 of the measurement mark when tilted is enhanced as compared with the image contrast 32 of the measurement mark when tilted.

Further, after detecting the measurement mark 12 at the angle a, the angle that the axial direction M of the sensor 11 has with respect to the normal direction L of the wafer 13 with respect to the perpendicular of the above angle (in this case, the normal direction L). The symmetric angle -a is set, and the measurement mark 12 is detected again at this symmetric angle -a. By averaging the result detected at the angle a and the result detected at the symmetric angle −a, the result detected at the first angle a can be corrected. As a result, the measurement mark 12 can be detected with higher accuracy as compared with the case where measurement is performed only at the angle a.

As another correction method, the measurement mark deviation amount Xa obtained from the relationship between the apparent measurement mark deviation amount Xa and the distance Y (Equation 1) is matched with the result measured only at the angle a. , The measurement mark 12 can be detected with higher accuracy as compared with the case where the measurement is performed only at the angle a.

Embodiment 2 FIG. 7 shows a measurement mark detection device according to Embodiment 2 of the present invention. FIG. 1 and FIG.
Parts denoted by the same reference numerals as in (A) and (B) indicate the same elements, and a description thereof will be omitted.

In FIG. 7A, the axial direction M of the sensor 11 and the normal L of the wafer 13 match, but in the second embodiment of the present invention, as shown in FIG. 1
3 is inclined rightward by an angle b with respect to the axial direction M. Here, the sensor 11 is fixed (installed non-movably) while remaining vertical in FIG. 7B. How to take the angle is arbitrary,
For example, the angle between the axial direction M of the sensor 11 fixed vertically and the surface direction of the wafer 13 may be b1.

FIG. 8 shows a case where the measurement mark 12 is detected from the sensor 11 located in the direction shown in FIG. In FIG. 8, the portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and thus description thereof will be omitted. In FIG. 8, reference numeral 82 denotes an image contrast of the measurement mark 12 detected by the sensor 11. FIG. 9 shows a case where the measurement mark 12 is detected from the sensor 11 located in the direction inclined rightward by the angle b shown in FIG. 7B. FIG. 9 and FIG.
Parts denoted by the same reference numerals as in (A) and (B) indicate the same elements, and a description thereof will be omitted. 9, reference numeral 92 denotes an image contrast of the measurement mark 12 detected by the sensor 11.

As described above, the measurement mark 12 is a structure having a three-dimensional structure.
Is tilted to the right by the angle b with respect to the axial direction M of
The side wall 15 of the measurement mark 12 is exposed to the fixed sensor 11. As a result, it is possible to obtain an effect that the image contrast 92 of the measurement mark 12 when tilted is enhanced as compared with the detected image contrast 82 of the measurement mark 12 when tilted. The angle b is preferably 0 degree <b ≦ ± 45 degrees with respect to the axial direction M of the sensor. However, the angle is not limited to the range of 0 degrees <b ≦ ± 45 degrees, and may be any angle as long as the axial direction M of the sensor 11 and the normal L of the wafer 13 do not match. The angle b1 is 45 degrees ≦ b1 ≦ 135 degrees (excluding b1 = 9) with respect to the axial direction M of the sensor 11 fixed while being vertical.
0 degree). But 45 degrees ≦ b1 ≦
The angle is not limited to the range of 135 degrees (excluding b1 = 90 degrees), and may be any angle as long as the axial direction M of the sensor 11 and the normal L of the wafer 13 do not match.

FIGS. 10A and 10B show a measuring method of a measuring mark and a measuring method including correction according to the second embodiment of the present invention. In FIG. 10, the portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and thus description thereof will be omitted.

As shown in FIG. 10A, first, the sensor 11 is immovably installed. Next, the normal direction L of the wafer 13 is set to a predetermined angle that does not coincide with the axial direction M of the sensor 11, for example, an angle b (angle setting step). The measurement mark 12 is detected at this angle b (detection step). The above is the method of measuring the measurement mark 12.

FIG. 10B shows a correction method for detecting the measurement mark 12 with higher accuracy. After detecting the measurement mark 12 at the angle b, the normal direction L of the wafer 13 is changed to the axial direction M of the sensor 11 as shown in FIG.
Is set to the symmetry angle −b with respect to the perpendicular (in this case, the axial direction M) of the above angle (angle resetting step). The measurement mark 12 is detected again at the symmetry angle −b (redetection step). Next, by averaging the result detected at the angle b and the result detected at the symmetry angle −b,
The result detected at the first angle b is corrected. As a result,
The measurement mark 12 can be detected with higher accuracy as compared with the case where the measurement is performed only at the angle b.

FIG. 11 shows another correction method according to the second embodiment of the present invention. In FIG. 11, portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and thus description thereof will be omitted. In FIG. 11, reference symbol Xb denotes an apparent measurement mark shift amount when the measurement mark 12 on the wafer 13 inclined by the angle b is viewed from the fixed sensor 11, and Y denotes a distance between the measurement mark 12 and the sensor 11. Distance.

As shown in FIG. 11, the relationship between the apparent measurement mark deviation amount Xb and the distance Y is as follows.

[0046]

(Equation 2) Can be requested. By matching the measurement mark deviation amount Xb obtained by Expression 1 with the result measured only at the angle b, it is possible to detect the measurement mark 12 with higher accuracy than in the case where measurement is performed only at the angle b.

As described above, according to the second embodiment, the normal direction L of the wafer 13 is inclined at an angle b that does not coincide with the axial direction M of the sensor 11 of the measuring apparatus, and the sensor 11 is non-movably installed. Can be. As a result, it is possible to obtain an effect that the image contrast 92 of the measurement mark when tilted is enhanced as compared with the image contrast 82 of the measurement mark when not tilted.

Further, after the measurement mark 12 is detected at the angle b, the angle that the normal direction L of the wafer 13 has with respect to the axial direction M of the sensor 11 is defined with respect to the perpendicular of the angle (in this case, the normal direction L). The symmetric angle -b is set, and the measurement mark 12 is detected again at this symmetric angle -b. By averaging the result detected at the angle b and the result detected at the symmetry angle −b, the result detected at the first angle b can be corrected. As a result, the measurement mark 12 can be detected with higher accuracy as compared with the case where measurement is performed only at the angle b.

As another correction method, the measurement mark deviation amount Xb obtained from the relationship (Equation 2) between the apparent measurement mark deviation amount Xb and the distance Y is matched with the result measured only at the angle b. , The measurement mark 12 can be detected with higher accuracy as compared with the case where the measurement is performed only at the angle b.

The first embodiment and the second embodiment are different from each other in that
The only difference is whether the wafer 13 is fixed or the sensor 11 is fixed. Therefore, after fixing the wafer 13 in the above-described first embodiment, the sensor 1
1 and the angle b at which the sensor 13 in Embodiment 2 described above is fixed and the wafer 13 is tilted, the axial direction M of the sensor 11 and the normal direction L of the wafer 13
The same angle can be considered as a relative angle between. In this case, Xa in Equation 1 and Xb in Equation 2 match.

Third Embodiment FIG. 12 shows a measurement mark detection device according to a third embodiment of the present invention. In FIG. 12, portions denoted by the same reference numerals as those in FIGS. 1A and 1B indicate the same elements, and a description thereof will be omitted. In the third embodiment,
In addition to the first embodiment, the angle p that the axial direction M of the sensor 11 has with respect to the normal L of the wafer 13 can be sequentially changed during measurement. In this case, the wafer 13 is immovably fixed as in the first embodiment.

FIG. 13 shows another measurement mark detection device according to the third embodiment of the present invention. FIG. 1 (A) in FIG.
Parts denoted by the same reference numerals as in (B) indicate the same elements, and a description thereof will be omitted. In the third embodiment, in addition to the second embodiment, the angle q that the normal line direction L of the wafer 13 has with respect to the axial direction M of the sensor 11 can be sequentially changed during measurement. In this case, the sensor 11 is immovably fixed as in the second embodiment.

As described above, according to the third embodiment, when measuring the measurement mark 12, the wafer 13 is immovably fixed and the angle between the axial direction M of the sensor 11 and the normal direction L of the wafer 13 is measured. Measurement can be performed while changing p sequentially. Therefore, the measurement can be performed at an angle at which the optimum image contrast of the measurement mark 12 can be obtained, so that the measurement can be performed with higher accuracy as compared with the first or second embodiment.

Further, at the time of measurement of the measurement mark 12, the measurement is performed while the sensor 11 is immovably fixed and the angle q between the axial direction M of the sensor 11 and the normal direction L of the wafer 13 is sequentially changed. be able to. Therefore, the measurement mark 12
Can be measured at an angle at which the optimum image contrast can be obtained, so that the measurement can be performed with higher accuracy as compared with the first or second embodiment.

In the above description, the measurement was performed while one of the wafer 13 and the sensor 11 was fixed and the other was sequentially moved. However, the wafer 13 and the sensor 1
It is also possible to measure while simultaneously moving both of them simultaneously.

The above-described measurement mark detection device can be applied to various measurement devices such as an overlay device in lithography and an alignment mechanism of an exposure device.

As described above, according to the measurement mark detection apparatus, the detection method, and the semiconductor device manufacturing method of the present invention, the relative movement of the wafer or the sensor enables (1) the measurement mark When forming a laminated film on
(2) When the height of the measurement mark is reduced in the processing after the formation of the measurement mark, or (3) When the layer or the base structure on which the measurement mark is formed has a reflectance or a refractive index that is hard to be detected by the measurement device. (4) a measurement mark detection device that prevents a decrease in image contrast of a measurement mark even when the measurement mark is formed, and (4) does not reduce measurement accuracy or disable measurement even when the formation state of the measurement mark is not good; A detection method and a method for manufacturing a semiconductor device can be provided.

[0057]

[Brief description of the drawings]

FIG. 1 is a diagram illustrating the principle of enhancing the image contrast of a measurement mark common to the embodiments of the present invention.

FIG. 2 is a diagram showing a measurement mark detection device according to the first embodiment of the present invention.

FIG. 3 is a diagram showing a case where a measurement mark 12 is detected from a sensor 11 located in a direction shown in FIG.

FIG. 4 is a diagram showing a case where a measurement mark 12 is detected from a sensor 11 located in a direction inclined rightward by an angle a shown in FIG. 2 (B).

FIG. 5 is a diagram illustrating a measurement method of a measurement mark and a measurement method including correction according to the first embodiment of the present invention.

FIG. 6 is a diagram showing another correction method according to the first embodiment of the present invention.

FIG. 7 is a diagram illustrating a measurement mark detection device according to a second embodiment of the present invention.

8 is a diagram showing a case where a measurement mark 12 is detected from a sensor 11 located in a direction shown in FIG. 7 (A).

FIG. 9 is a diagram showing a case where a measurement mark 12 is detected from a sensor 11 located in a direction inclined rightward by an angle b shown in FIG. 7 (B).

FIG. 10 is a diagram illustrating a measurement method of a measurement mark and a measurement method including correction according to the second embodiment of the present invention.

FIG. 11 is a diagram showing another correction method according to the second embodiment of the present invention.

FIG. 12 is a diagram illustrating a measurement mark detection device according to a third embodiment of the present invention.

FIG. 13 is a diagram showing another measurement mark detection device according to the third embodiment of the present invention.

FIG. 14 is a diagram illustrating a conventional method for detecting a measurement mark.

[Explanation of symbols]

8 resist, 10 interlayer film, 11 sensor, 1
2 measurement marks, 13 wafers, 15 sidewalls,
32, 42, 82, 92 Image contrast.

Claims (11)

[Claims] 1. A measurement mark detection device for detecting a measurement mark provided on a wafer by a sensor, wherein an axial direction of the sensor has a predetermined angle that does not coincide with a normal direction of the wafer, A measurement mark detection device, wherein the wafer is non-movably installed. 2. The measurement mark detection device according to claim 1, wherein a predetermined angle that the sensor axis direction has with respect to a normal direction of the wafer can be variably set. 3. A measurement mark detection device for detecting a measurement mark provided on a wafer by a sensor, wherein a normal direction of the wafer has a predetermined angle that does not coincide with an axial direction of the sensor, A measurement mark detection device, wherein the sensor is non-movably installed. 4. The measurement mark detection device according to claim 3, wherein a predetermined angle that a normal line direction of the wafer has with respect to an axial direction of the sensor can be set variably. 5. A measurement mark detection device for detecting a measurement mark provided on a wafer by a sensor, wherein an axis direction of the sensor has a predetermined first angle that does not coincide with a normal direction of the wafer. The normal direction of the wafer has a predetermined second angle that does not coincide with the axial direction of the sensor, and the predetermined first angle and the second angle can be variably set. Mark detection device. 6. The measurement mark detection device according to claim 1, wherein the measurement mark is used for overlay or alignment positioning in lithography. 7. A measurement mark detection method for detecting a measurement mark provided on a wafer by a sensor, wherein the step of non-movably installing the wafer provided with the measurement mark includes: A measurement mark detection method, comprising: an angle setting step of setting a predetermined angle that does not match a normal direction of the wafer; and a detection step of detecting a measurement mark at an angle set in the angle setting step. . 8. An angle for setting, after the detecting step, an angle that the axial direction of the sensor has with respect to a normal direction of the wafer to a symmetric angle with respect to a predetermined vertical angle set in the angle setting step. A resetting step, a re-detecting step of detecting a measurement mark at an angle set in the angle resetting step, and averaging a result detected in the detecting step and a result detected in the re-detecting step. 8. The method according to claim 7, further comprising a step of correcting a result detected in the detection step. 9. A measurement mark detection method for detecting a measurement mark provided on a wafer by a sensor, wherein the sensor is immovably installed, and a normal direction of the wafer is set in an axial direction of the sensor. A measurement mark detection method comprising: an angle setting step of setting a predetermined angle that does not match the angle; and a detection step of detecting a measurement mark at the angle set in the angle setting step. 10. After the detecting step, an angle at which a normal line direction of the wafer faces the axial direction of the sensor is set to a symmetric angle with respect to a predetermined vertical angle set in the angle setting step. An angle resetting step, a re-detection step of detecting a measurement mark at an angle set in the angle resetting step, and averaging a result detected in the detection step and a result detected in the re-detection step. 10. The method according to claim 9, further comprising: correcting a result detected in the detecting step. 11. A method for manufacturing a semiconductor device comprising the measurement mark detection method according to claim 7.