JP2006201027A - Method for acquiring shape characteristics program, and recording medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for acquiring shape characteristics and a program, capable of acquiring accurately a shape characteristic of the outer circumferential part of a semiconductor wafer. <P>SOLUTION: This method acquires shape data along radial directions of obverse and reverse faces of the semiconductor wafer, calculates the midpoint of the semiconductor wafer based on the shape data, and calculates a reference curve of a quadratically approximated curve, based on the midpoint. A profile, after removing a component of the reference curve, is found from the shape data of the obverse and reverse faces of the semiconductor wafer, a prescribed section excepting the outer circumferential part of the semiconductor wafer is fit further with a linear function, and a component of the linear function is thereafter subtracted from the fit profile. A profile with the prescribed section, having a reference line 27 substantially free from displacement, is obtained by this manner. Shift amounts T1, T2 with respect to the reference line 27 are found in the prescribed section in the outer circumferential part of the semiconductor wafer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a shape characteristic acquisition method, a program, and a recording medium for acquiring a shape characteristic of an outer peripheral portion of a semiconductor wafer.

Conventionally, semiconductor wafers such as silicon wafers are generally chamfered by cutting a silicon single crystal ingot grown by the Czochralski method or the floating zoone method into a thin plate shape. It is manufactured by performing processing such as etching and grinding.
In recent years, semiconductor devices have been highly integrated, and quality requirements for the shape of a semiconductor wafer serving as a substrate for semiconductor devices have become strict.
In addition, the movement to reduce the cost of semiconductor devices by forming a large number of chips from a single semiconductor wafer is accelerating. That is, up to the outer periphery of the semiconductor wafer (in the case of the chamfered portion being formed, the portion excluding the chamfered portion and the inner region adjacent to the chamfered portion) so that the device can be formed over a wide range of the surface of the semiconductor wafer. It is desired to use it.
Here, a sagging shape called roll-off and a cut-off shape called flip-up exist on the outer peripheral portion of the semiconductor wafer.
If there are large roll-offs and flip-ups on the outer periphery of the semiconductor wafer, the quality requirements for the shape of the semiconductor wafer cannot be satisfied, and normal semiconductor devices cannot be produced.

Therefore, in order to meet high quality requirements and to reduce the cost of the semiconductor device, it is necessary to accurately evaluate the shape characteristic of the outer peripheral portion of the semiconductor wafer.
Therefore, the following method has been proposed as a method for obtaining the shape characteristic of the outer peripheral portion of the semiconductor wafer.
As shown in FIG. 23, it is considered that the inside of a predetermined dimension from the outermost periphery of the semiconductor wafer 2 (for example, a range of 3 mm to 6 mm inside from the outermost periphery) is sufficiently flat, and the predetermined shape data of the measured semiconductor wafer 2 is determined. A reference line 23 in a section (for example, a range of 3 mm to 6 mm from the outermost periphery) is obtained, and a deviation amount T from the reference line 23 in a predetermined position (for example, a position 1 mm inside from the outer periphery) of the outer periphery of the semiconductor wafer 2. (ROA (Roll Off Amount) value) is calculated (see Non-Patent Document 1, for example).
In FIG. 23, the profile of the portion surrounded by the one-dot chain line circle is indicated by reference numeral 20, and the reference numeral H indicates a chamfered portion.
More specifically, first, as shown in FIG. 24, the shape data 21 of the front surface (or back surface) of the semiconductor wafer 2 is acquired. Next, an approximate straight line (linear function), approximate curve (quadratic curve (quadratic function), or cubic curve) obtained by using a least square method or the like for a predetermined section of the shape data 21 is used. (Cubic function)) to obtain a profile. In FIG. 23, a section of 3 mm to 6 mm from the outermost periphery of the shape data 21 is fitted with a first-order approximate straight line 22. Since the section is considered to be flat, a profile 20 is obtained by subtracting the component of the first-order approximate straight line 22 from the fitted profile. In other words, since the predetermined section is considered to be flat, the predetermined section (section from 3 mm to 6 mm from the outermost periphery) is made to be the reference line 23 having substantially no displacement. Thereafter, a deviation amount T (ROA (Roll Off Amount) value) from the reference line 23 at a predetermined position (for example, a position 1 m inside from the outermost periphery) of the outer peripheral portion of the semiconductor wafer 2 is calculated.

Kobelco Research Institute, Ltd., "Edge roll-off measuring device", [online], [Searched on November 29, 2004], Internet <URL: http://www.kobelcokaken-it.com/leo/item/ler/ index.html>

However, in such a method for obtaining the shape characteristic of the outer peripheral portion of the semiconductor wafer, the ROA depends on the length and position of the section when the shape data 21 of the semiconductor wafer 2 is fitted with an approximate curve and the reference line 23 is calculated. The value of may be different. For example, when the reference line 23 is calculated by fitting a section of 3 mm to 6 mm from the outermost periphery of the semiconductor wafer 2, and when the reference line 23 is calculated by fitting a section of 10 to 14 mm from the outermost periphery of the semiconductor wafer 2 And the ROA value is different.
Therefore, there is a problem that it is difficult to obtain accurate shape characteristics of the outer peripheral portion of the semiconductor wafer in the method for acquiring the shape characteristics of the outer peripheral portion of the semiconductor wafer as described above.

  The objective of this invention is providing the shape characteristic acquisition method program and recording medium which can acquire the shape characteristic of the outer peripheral part of a semiconductor wafer correctly.

As a result of intensive studies by the present inventors, the present inventors, in the conventional method for obtaining the shape characteristic of the outer peripheral portion of a semiconductor wafer, determine the semiconductor according to the length and position of the section in which the reference line 23 is calculated by fitting. I guessed that it might be affected by the warpage of the wafer. That is, it was considered that the ROA value fluctuated depending on whether or not the semiconductor wafer was warped.
The shape characteristic acquisition method of the present invention has been devised based on such knowledge.

  The shape characteristic acquisition method of the present invention is a shape characteristic acquisition method for acquiring a shape characteristic of an outer peripheral portion of a semiconductor wafer, and a shape data acquisition step for acquiring shape data along the radial direction of the front and back surfaces of the semiconductor wafer; A midpoint calculation step of calculating the midpoint of the thickness of the semiconductor wafer from the shape data of the front and back surfaces of the semiconductor wafer acquired in the shape data acquisition step, and a reference curve that is a quadratic approximate curve is calculated from the midpoint. A reference curve calculating step, a profile obtaining step for obtaining a profile obtained by removing the component of the reference curve from the shape data of the front surface and / or back surface of the semiconductor wafer, and a predetermined section of the profile excluding the outer peripheral portion of the semiconductor wafer. After fitting with a linear function, the component of the linear function is subtracted from the fitted profile so that the predetermined section is substantially omitted. A shape characteristic acquisition step for obtaining a shape characteristic of the outer peripheral portion of the semiconductor wafer by determining a deviation amount at a predetermined position of the outer peripheral portion of the semiconductor wafer with respect to the reference line so as to be a reference line having no position. Features.

According to this invention, the shape data of the front and back surfaces of the semiconductor wafer is acquired, the midpoint of the thickness of the semiconductor wafer is calculated from the shape data, and the reference curve that is a quadratic approximate curve is calculated from the midpoint. Yes. This reference curve shows only the warpage of the semiconductor wafer that does not reflect the shape of the outer periphery of the semiconductor wafer (roll-off component, flip-up component).
Then, by removing the component of the reference curve from the shape data of the semiconductor wafer, a profile from which the warp of the semiconductor wafer is removed is obtained.
Thereafter, a predetermined section of the profile excluding the outer peripheral portion of the semiconductor wafer is fitted with a linear function, and the component of the linear function is subtracted from the fitted profile. Since the amount of deviation in the predetermined position of the outer peripheral portion of the semiconductor wafer with respect to this reference line is obtained, it is possible to grasp the shape characteristics of the outer peripheral portion of the semiconductor wafer by removing the warp component of the semiconductor wafer, The shape characteristic of the outer peripheral portion of the semiconductor wafer can be accurately acquired without being affected by the warp of the semiconductor wafer.
Therefore, according to the shape characteristic acquisition method of the present invention, the shape characteristic of the outer peripheral portion of the semiconductor wafer can be accurately acquired regardless of the length and position of the section for obtaining the reference line.

  In the present invention, the roughness component of the shape data of the front surface and / or back surface of the semiconductor wafer may be removed by moving average processing before the profile acquisition step.

Further, the present invention can also be established as a program, and the program of the present invention calculates the midpoint of calculating the midpoint of the thickness of the semiconductor wafer from the shape data of the front and back surfaces of the semiconductor wafer along the radial direction. A reference curve calculation step of calculating a reference curve which is a quadratic approximate curve from the midpoint, and a profile obtained by removing the reference curve component from the shape data of the front surface and / or back surface of the semiconductor wafer After fitting a predetermined section of the profile excluding the outer periphery of the semiconductor wafer with a linear function, a component of the linear function is subtracted from the fitted profile, and the predetermined section is substantially displaced. By determining the amount of deviation at a predetermined position of the outer peripheral portion of the semiconductor wafer with respect to this reference line, It is intended for executing the shape characteristic obtaining step of obtaining the shape characteristics of the outer peripheral portion of the conductor wafer to the computer.
According to the present invention as described above, since the computer can execute the shape characteristic acquisition method described above by installing it on a general-purpose computer, it is possible to greatly promote the use of the present invention.

The recording medium of the present invention stores the above-described program.
By causing the computer to execute the program recorded on this recording medium, the above-described shape characteristic acquisition method of the present invention can be executed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a measuring apparatus 1 for obtaining the shape characteristics of the outer peripheral portion of a semiconductor wafer 2.
Here, examples of the semiconductor wafer 2 to be measured include a silicon wafer and a compound semiconductor wafer (GaAs, GaP, InAs, etc.).
The measuring apparatus 1 acquires the shape characteristics of the outer periphery of the semiconductor wafer 2 based on the shape measuring apparatus 11 for acquiring the shape data of the front and back surfaces of the semiconductor wafer 2 and the shape data measured by the shape measuring apparatus 11. And a shape characteristic acquisition device 12 to be used.
For example, the shape measuring apparatus 11 sucks and holds the central portion of the semiconductor wafer 2, disposes displacement meters on the front and back sides of the semiconductor wafer 2, and moves the displacement meters along the radial direction of the semiconductor wafer 2. Is. Thereby, the shape of the front and back surfaces along the radial direction of the semiconductor wafer 2 can be acquired.
The displacement meter is provided with a laser oscillator and a CCD camera, and is irradiated with laser light at a predetermined interval perpendicularly to the front surface or the back surface of the semiconductor wafer 2 and acquired by the CCD camera. The displacement between the focal point of the image acquired by the CCD camera and the reference point is calculated, and the displacement is measured.

The shape characteristic acquisition device 12 includes a storage unit 121 and a calculation unit 122, and is connected to the shape measurement device 11.
The storage unit 121 stores shape data 21 (see FIG. 2) measured by the shape measuring apparatus 11 and a program executed by the calculation unit 122.
The calculation unit 122 is configured by, for example, a CPU (Central Processing Unit), and includes a midpoint calculation unit 122A, a reference curve calculation unit 122B, a profile acquisition unit 122C, and an analysis unit 122D. Each of these means 122A-122D is comprised when the calculating part 122 reads the program memorize | stored in the memory | storage part 121. FIG.
This program is stored in a recording medium such as an optical disk. By installing the program stored in the recording medium in the shape characteristic acquisition device 12, the program can be stored in the storage unit 121 of the shape characteristic acquisition device 12.

The midpoint calculation unit 122A reads the shape data of the semiconductor wafer 2 stored in the storage unit 121, and calculates a plurality of midpoints of the thickness of the semiconductor wafer 2 from the shape data.
The reference curve calculation unit 122B fits the plurality of midpoints calculated by the midpoint calculation unit 122A using the least square method, and calculates a secondary reference curve 25 (see FIG. 3).
The profile acquisition unit 122C obtains a profile 26 (see FIG. 3) obtained by removing the component of the reference curve 25 from the shape data 21 on the front surface and the shape data 21 on the back surface of the semiconductor wafer 2.
The analyzing unit 122D fits a predetermined section of the profile 26 excluding the outer peripheral portion of the semiconductor wafer 2 in the profile 26 acquired by the profile acquiring unit 122C with a linear function, and from the fitted profile, the linear function The profile 28 having the reference line 27 (see FIG. 4) in which the predetermined section has almost no displacement is obtained.
Then, a deviation amount with respect to the reference line 27 at a predetermined position of the outer peripheral portion of the front surface or the back surface of the semiconductor wafer 2 is calculated.

Next, a shape characteristic acquisition method using such a measuring apparatus 1 will be described.
Here, when the shape characteristic of the outer peripheral portion of the semiconductor wafer 2 having warpage is small (shape characteristic acquisition method 1), the thickness change is large and the thickness decreases from the outer peripheral portion toward the central portion. When acquiring the shape characteristic of the outer periphery of the semiconductor wafer 2 (shape characteristic acquisition method 2), the shape characteristic of the outer periphery of the semiconductor wafer 2 having a substantially flat back surface and a concave surface is acquired. Three examples of cases (shape characteristic acquisition method 3) will be described.

[Method 1 for obtaining shape characteristics of outer periphery of semiconductor wafer]
A method for acquiring the shape characteristic of the outer peripheral portion of the semiconductor wafer 2 having a small thickness change and warping will be described with reference to FIGS. 2 to 4 and the flowchart of FIG.
The shape measuring device 11 of the measuring device 1 measures the shape of the front and back surfaces along the radial direction of the semiconductor wafer 2 and acquires the shape data 21 as shown in FIG. 2A (processing S1, shape data acquiring step) ). Here, the shape data of the front surface of the semiconductor wafer 2 is 21A, and the shape data of the back surface is 21B.
It is sufficient that the shape data 21 is data from the position of the outermost periphery of the semiconductor wafer 2 to a position about 30 mm inside. In addition, when the outer peripheral edge of the semiconductor wafer is chamfered and a chamfered portion is formed, the shape data may be from the position excluding the chamfered portion to a position about 30 mm inside from the outermost periphery.

In this embodiment, since the chamfered portion H is formed in the semiconductor wafer 2, the chamfered portion H is excluded, and as shown in FIG. The shape data 21 up to the inner position is acquired. The 0 mm position indicates the outermost periphery of the semiconductor wafer 2.
In FIG. 2A, the curve of the shape data 21A and the curve of the shape data 21B are arranged with a predetermined distance so as to be easy to see. In the present invention, the shape data 21 on the front and back surfaces of the semiconductor wafer 2 is sufficient, and the exact thickness of the semiconductor wafer 2 is not required.
The shape data 21 (21A, 21B) acquired in this way is stored in the storage unit 121 of the shape characteristic acquisition device 12.

Next, as shown in FIG. 2B, a midpoint of the thickness of the semiconductor wafer 2 is obtained by the midpoint calculation means 122A of the calculation unit 122 of the shape characteristic acquisition device 12. The shape data 21 of the front and back surfaces of the semiconductor wafer 2 stored in the storage unit 121 of the shape characteristic acquisition device 12 is read, and the thickness of the semiconductor wafer 2 is increased along the radial direction at a predetermined interval, for example, every 1 mm. A point is calculated (process S2, midpoint calculation step). From the plurality of midpoints, the center line 24 of the semiconductor wafer 2 can be obtained. In the present embodiment, the midpoint is calculated in a range from a position 0.5 mm inside from the outermost circumference to a position 27 mm inside from the outermost circumference, and the center line 24 is obtained.
The midpoint calculated by the midpoint calculation unit 122A is stored in the storage unit 121 and then read out by the reference curve calculation unit 122B. Then, as shown in FIG. 3C, the reference curve calculation means 122B calculates a reference curve 25, which is a quadratic approximate curve, from the plurality of midpoints using the least square method (processing S3, reference Curve calculation step).
Here, the range for calculating the reference curve 25 is, for example, a range from the outer peripheral edge of the semiconductor wafer 2 to the inner side of 0.5 mm to 27 mm.

The range for calculating the reference curve 25 may be a range including the reference line 27 calculated in the latter stage, but in particular, the outer peripheral portion of the semiconductor wafer 2 (here, the outer peripheral portion is a portion excluding the chamfered portion H). And the range from the outermost periphery of the semiconductor wafer 2 to a position 3 mm inside) is preferably included.
The reference curve 25 obtained by the reference curve calculation means 122B is, for example, Y = 0.0038X ² −0.1139X−0, when the vertical axis in FIG. 3C is the Y axis and the horizontal axis is the X axis. It is expressed by the expression 3224. As shown in FIG. 3C, the reference curve 25 is in a state of substantially overlapping with the center line 24 in a portion other than the vicinity of 1 mm from the outermost periphery.
The reference curve 25 indicates a warp component of the semiconductor wafer 2 and is obtained by removing local displacement, for example, a roughness component, a roll-off component, and a flip-up component.
The reference curve 25 is stored in the storage unit 121.

Next, the secondary reference curve 25 stored in the storage unit 121 is read out, and as shown in FIG. 3D, the profile acquisition unit 122C calculates the reference curve 25 from the shape data 21A on the surface of the semiconductor wafer 2. A profile 26A from which components are removed is obtained. That is, the profile 26A is obtained by (shape data 21A) − (component of the reference curve 25). The profile 26B from which the component of the reference curve 25 is removed is obtained from the shape data 21B on the back surface of the semiconductor wafer 2 by the same method (processing S4, profile acquisition step).
As a result, the warp component is removed from the shape data 21 of the front and back surfaces of the semiconductor wafer 2, and the shape curve (profile 26 (26A) where the roll-off component or flip-up component of the outer periphery of the semiconductor wafer 2 remains is left. , 26B)) can be acquired.

Thereafter, the analysis unit 122D fits a predetermined section (for example, a section of 10 to 15 mm from the outermost periphery) of the profile 26 excluding the outer peripheral portion of the semiconductor wafer 2 with a linear function (approximate straight line) (processing S5).
Then, the component of the linear function is subtracted from the fitted profile so that the predetermined section (for example, a section of 10 to 15 mm from the outermost periphery) becomes the reference line 27 having almost no displacement (processing S6). .
FIG. 4E shows a profile 28A (28) obtained by fitting the surface profile 26A of the semiconductor wafer 2 with a linear function and then subtracting the component of the linear function, and FIG. The profile 28B (28) is obtained by subtracting the component of the linear function after fitting the profile 26B on the back surface of the semiconductor wafer 2 with the linear function.
Then, a deviation amount at a predetermined position (for example, a position 1 mm from the outermost periphery) of the outer peripheral portion of the semiconductor wafer 2 with respect to the reference line 27 is obtained (processing S7, shape characteristic acquisition step). T1 in FIG. 4 (E) and T2 in FIG. 4 (F) become a deviation amount (ROA value), and in a semiconductor wafer 2 having a small change in thickness and warping, rolls are formed on the outer peripheral portions of the front and back surfaces of the semiconductor wafer 2. It can be confirmed that an off state has occurred.

By performing the above operation over the entire circumference of the semiconductor wafer 2, the shape of the entire circumference of the outer peripheral portion of the semiconductor wafer 2 can be grasped.
That is, the shape data of the front and back surfaces along the radial direction of the semiconductor wafer 2 is measured at predetermined angular intervals, for example, every 45 ° intervals along the circumferential direction of the semiconductor wafer 2, and based on each shape data 21. By obtaining the amount of deviation at a predetermined position (for example, a position 1 mm from the outermost periphery) of the outer peripheral portion of the semiconductor wafer 2 with respect to the reference line 27, the shape of the entire outer peripheral portion of the semiconductor wafer 2 can be grasped.

[Method 2 for obtaining shape characteristics of outer periphery of semiconductor wafer]
Next, referring to FIG. 5 and FIG. 6 to FIG. 8, a case where the shape characteristic of the outer peripheral portion of the semiconductor wafer 2 is obtained such that the change in thickness is large and the thickness decreases from the outer peripheral portion toward the central portion. explain.
When the shape characteristic of the semiconductor wafer having a small thickness change described above is acquired (shape characteristic acquisition method 1), the shape characteristic is acquired through the same process.
As shown in FIG. 6A, the shape data 21 (21A, 21B) of the front and back surfaces of the semiconductor wafer 2 is acquired (process S1), and the midpoint of the thickness of the semiconductor wafer 2 as shown in FIG. The center line 24) is calculated (process S2). Further, as shown in FIG. 7C, a quadratic reference curve 25 is calculated using the least square method (processing S3), and as shown in FIG. 7D, the shape data 21 of the surface of the semiconductor wafer 2 is obtained. A profile 26 (26A, 26B) from which the component of the reference curve 25 is removed is obtained (step S4). Here, the inclination remains in the profile 26 in which the warp component is removed from the shape data 21 of the front and back surfaces of the semiconductor wafer 2.

Next, as shown in FIGS. 8E and 8F, a predetermined section of the profile 26 (for example, a section of 10 to 15 mm from the outermost periphery) excluding the outer peripheral portion of the semiconductor wafer 2 is fitted with a linear function. Then, the component of the linear function is subtracted from the fitted profile so that the predetermined section becomes the reference line 27 having almost no displacement (process S6).
By this operation, the inclination of the profile 26 is corrected, and profiles 28 (28A, 28B) are obtained.
Then, a deviation amount (ROA value) of a predetermined position (for example, a position 1 mm from the outermost periphery) of the outer periphery of the semiconductor wafer with respect to the reference line 27, that is, T1 and T2 in FIGS. By calculating | requiring (process S7), the change of thickness is large and it can confirm that the roll-off has arisen in the outer peripheral part of the front and back of the semiconductor wafer 2 that thickness decreases toward a center part from an outer peripheral part.
By performing the above operation over the entire circumference of the semiconductor wafer 2, the shape of the entire circumference of the outer peripheral portion of the semiconductor wafer 2 can be grasped.

[Method 3 for obtaining shape characteristics of outer periphery of semiconductor wafer]
Next, with reference to FIG. 5 and FIGS. 9 to 11, a case will be described in which the shape characteristics of the outer peripheral portion of the semiconductor wafer 2 having a substantially flat back surface and a concave surface are described.
The shape characteristic is obtained through the same process as the case where the shape characteristic of the semiconductor wafer 2 with a small thickness change is obtained.
As shown in FIG. 9A, the shape data 21 (21A, 21B) of the front and back surfaces of the semiconductor wafer 2 is acquired (process S1), and the center point (center line 24) is obtained as shown in FIG. 9B. Calculate (processing S2). Further, as shown in FIG. 10C, a quadratic reference curve 25 is calculated using the least square method (processing S3), and as shown in FIG. 10D, the shape data 21 of the surface of the semiconductor wafer 2 is obtained. A profile 26 (26A, 26B) from which the component of the reference curve 25 is removed is obtained (step S4).

Next, as shown in FIGS. 11E and 11F, a predetermined section of the profile 26 (for example, a section of 10 to 15 mm from the outermost periphery) excluding the outer peripheral portion of the semiconductor wafer 2 is fitted with a linear function. Then, the component of the linear function is subtracted from the fitted profile so that the predetermined section becomes the reference line 27 having almost no displacement (process S6).
A deviation amount (ROA value) of a predetermined position of the semiconductor wafer 2 with respect to the reference line 27, that is, T1 and T2 in 11 (E) and (F) is obtained (processing S7), whereby the front and back surfaces of the semiconductor wafer 2 are obtained. It can be confirmed that a rip-up has occurred on the outer peripheral portion of the.
By performing the above operation over the entire circumference of the semiconductor wafer 2, the shape of the entire circumference of the outer peripheral portion of the semiconductor wafer 2 can be grasped.

According to this embodiment, the following effects can be achieved.
(1) The shape data 21 of the front and back surfaces of the semiconductor wafer 2 is acquired, the midpoint of the thickness of the semiconductor wafer 2 is calculated from the shape data 21, and a quadratic approximate curve from the midpoint using the least square method The reference curve 25 is calculated. This reference curve 25 shows only the warp of the semiconductor wafer 2 that does not reflect the shape of the outer peripheral portion of the semiconductor wafer 2 (roll-off component, flip-up component).
Then, by removing the component of the reference curve 25 from the shape data 21 of the semiconductor wafer 2, the shape of the outer peripheral portion of the semiconductor wafer 2 (roll-off component, flip-up component) can be removed without removing the semiconductor wafer 2. It is possible to obtain a profile 26 from which only two warpages are removed.
Thereafter, a predetermined section of the profile 26 excluding the outer peripheral portion of the semiconductor wafer 2 is fitted with a linear function, and the component of the linear function is subtracted from the fitted profile so that the predetermined section is substantially free from displacement. Since a deviation amount at a predetermined position of the outer peripheral portion of the semiconductor wafer 2 with respect to the reference line 27 is obtained, the warp component of the semiconductor wafer 2 is removed and the shape characteristics of the outer peripheral portion of the semiconductor wafer 2 are obtained. Can be grasped. Therefore, the shape characteristics of the outer peripheral portion of the semiconductor wafer 2 can be accurately acquired without being affected by the warp of the semiconductor wafer 2.
Therefore, according to the shape characteristic acquisition method of the present embodiment, the shape characteristic of the outer peripheral portion of the semiconductor wafer 2 can be accurately acquired regardless of the length and position of the section for obtaining the reference line 27.

(2) In the present embodiment, the reference curve 25 is calculated from the midpoint of the range from the outermost periphery of the semiconductor wafer 2 to the inside of 0.5 mm to 27 mm using the least square method. Thus, since the range for obtaining the reference curve 25 is relatively wide, the warp component of the semiconductor wafer 2 can be accurately indicated by the reference curve 25. Thereby, the profile 26 from which the warp of the semiconductor wafer 2 is removed can be accurately obtained at a later stage, and furthermore, the shape characteristic of the outer peripheral portion of the semiconductor wafer 2 can be accurately obtained.

It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above-described embodiment, the range for calculating the reference line 27 from the profile 26 from which the warp of the semiconductor wafer 2 is removed is the range from 10 mm to 15 mm inside from the outermost periphery of the semiconductor wafer 2, but is not limited thereto. For example, it may be a range from 3 mm to 6 mm inside from the outermost periphery of the semiconductor wafer 2, or may be a range from 3 mm to 27 mm inside from the outermost periphery of the semiconductor wafer 2.
In the present invention, the reference line 27 is acquired by using the profile 26 from which the warp of the semiconductor wafer 2 is removed, and the shape characteristic of the outer peripheral portion is grasped. Therefore, the shape characteristic of the outer peripheral portion of the semiconductor wafer 2 can be obtained without being affected by the warp regardless of the length and position of the reference line 27 section. The position can be set as appropriate.

Furthermore, in the said embodiment, although the shape characteristic of the outer peripheral part of the front and back of the semiconductor wafer 2 was acquired, you may acquire not only this but the shape characteristic of the outer peripheral part only of the surface of the semiconductor wafer 2, for example.
In the embodiment, after calculating the reference curve 25, the profile obtained by removing the component of the reference curve 25 is obtained from the shape data 21 of the front and back surfaces of the wafer 2. However, the present invention is not limited to this. In the former stage, the roughness component of the shape data 21 on the front and back surfaces of the semiconductor wafer 2 may be removed by moving average processing. Thereby, shape data can be smoothed.

Next, examples of the present invention will be described.
In order to confirm the presence or absence of the warpage of the semiconductor wafer in the evaluation of the shape characteristics of the outer periphery of the semiconductor wafer, the semiconductor wafer is changed with only the warpage being changed without changing the shape characteristics of the outer periphery of the semiconductor wafer. The shape characteristic of the outer peripheral part of was evaluated.
Specifically, a semiconductor wafer having a 500 nm SiO ₂ thin film formed on the back surface of a substrate having a diameter of 200 mm was used, and the shape characteristics of the outer periphery of the semiconductor wafer before and after the SiO ₂ thin film was peeled were evaluated. It has been previously confirmed that only the warpage of the semiconductor wafer changes before and after the SiO ₂ thin film is peeled off, and the shape characteristics of the outer peripheral portion do not change.

As shown in FIG. 12A, the semiconductor wafer before peeling the SiO ₂ thin film has a warp that is recessed in a concave shape, and the semiconductor wafer after peeling the SiO ₂ thin film is shown in FIG. As shown in FIG. 12A and 12B, the upper curve is the shape data 21 (21A) of the surface of the semiconductor wafer, and the lower curve is the shape data 21 (21B) of the back surface of the semiconductor wafer. 12A and 12B is a reference curve 25 indicating the warpage of the semiconductor wafer.
The SiO ₂ thin film was peeled off by washing the semiconductor wafer with a hydrofluoric acid aqueous solution.

Example 1
With respect to the semiconductor wafer before peeling off the SiO ₂ thin film, the method for obtaining the shape characteristic of the outer peripheral portion of the semiconductor wafer of the present invention was executed.
The method for obtaining the shape characteristic of the outer peripheral portion of the semiconductor wafer was performed based on the procedure described in the above embodiment.
First, the shape data of the front and back surfaces of the semiconductor wafer from the position 0.5 mm inside from the outermost periphery to the position 27 mm inside from the outermost periphery is obtained, and the midpoint of the thickness of the semiconductor wafer is obtained based on this shape data, and the minimum A reference curve, which is a quadratic approximate curve, was calculated from the midpoint using the square method. The range for calculating the reference curve was from 0.5 mm to 27 mm inside from the outermost periphery of the semiconductor wafer.
Thereafter, a profile obtained by removing the components of the reference curve was obtained from the shape data of the surface of the semiconductor wafer. Then, a predetermined section (section from 3 to 6 mm from the outermost periphery) excluding the outer peripheral portion of the semiconductor wafer was fitted with a linear function. Further, the component of the linear function is subtracted from the fitted profile so that the predetermined section becomes a reference line with almost no displacement.
Such an operation was measured for each predetermined angle along the circumferential direction of the semiconductor wafer, and a profile having a reference line was obtained over the entire outer circumference of the semiconductor wafer.
The results are shown in FIG.

Next, a semiconductor wafer after removal of the SiO ₂ thin film, the same procedure as the semiconductor wafer before peeling the SiO ₂ thin film was executed the acquisition method of the shape characteristics of the outer peripheral portion of the semiconductor wafer of the present invention.
The results are shown in FIG.
13A and 13B, it can be seen that the same profile could be obtained even if the warpage of the semiconductor wafer changed due to the peeling of the SiO ₂ thin film.
It was confirmed that similar shape characteristics could be obtained without being affected by warpage before and after the SiO ₂ thin film was peeled off.

(Example 2)
For the semiconductor wafer before peeling the SiO ₂ thin film and the semiconductor wafer after peeling the thin film, the method for obtaining the shape characteristic of the outer peripheral portion of the semiconductor wafer of the present invention was executed.
The conditions for Example 1 are the same as those of Example 1 except that the section for obtaining the reference line is a section that is 10 to 14 mm inside from the outermost periphery of the semiconductor wafer.
The results are shown in FIGS. 14 (A) and (B).
FIG. 14A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 14B shows the profile of the semiconductor wafer after peeling off the SiO ₂ thin film.
14A and 14B, it can be seen that the same profile can be obtained even if the warpage of the semiconductor wafer changes due to the peeling of the SiO ₂ thin film.
It was confirmed that similar shape characteristics could be obtained without being affected by warpage before and after the SiO ₂ thin film was peeled off.

(Example 3)
For the semiconductor wafer before peeling the SiO ₂ thin film and the semiconductor wafer after peeling the thin film, the method for obtaining the shape characteristic of the outer peripheral portion of the semiconductor wafer of the present invention was executed.
The conditions for Example 1 are the same as those of Example 1 except that the section for obtaining the reference line is a section 3 to 27 mm inside from the outermost periphery of the semiconductor wafer.
The results are shown in FIGS. 15 (A) and 15 (B).
FIG. 15A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 15B shows the profile of the semiconductor wafer after peeling off the SiO ₂ thin film.
15A and 15B, it can be seen that the same profile can be obtained even if the warpage of the semiconductor wafer changes due to the peeling of the SiO ₂ thin film.
It was confirmed that similar shape characteristics could be obtained without being affected by warpage before and after the SiO ₂ thin film was peeled off.

(Evaluation of Examples 1 to 3)
From the above Examples 1 to 3, it can be confirmed that even if the warpage of the semiconductor wafer changes due to the peeling of the SiO ₂ thin film, it is possible to confirm that the same profile is obtained. It was found that the shape characteristics can be obtained accurately.
It was also confirmed that the same profile can be obtained and the same shape characteristic can be obtained even if the length and position of the section for obtaining the reference line are changed.
That is, it was confirmed that the shape characteristic acquisition method of the present invention can accurately acquire the shape characteristic of the outer peripheral portion of the semiconductor wafer.

(Comparative Example 1)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
First, the shape data of the surface of the semiconductor wafer before peeling off the SiO ₂ thin film was obtained. Next, in this shape data, a section 3 mm to 6 mm inside from the outermost periphery of the semiconductor wafer was fitted with a first-order approximate straight line (linear function) obtained using the least square method. Thereafter, a profile obtained by subtracting the component of the first-order approximate straight line (linear function) from the fitted profile was obtained. A section 3 mm to 6 mm inside from the outermost periphery of the semiconductor wafer is a reference line.
Such an operation was measured for each predetermined angle along the circumferential direction of the semiconductor wafer, and a profile having a reference line was obtained over the entire outer circumference of the semiconductor wafer. This profile is shown in FIG.

In the same manner, the shape data of the surface of the semiconductor wafer after the SiO ₂ thin film is peeled off is obtained, and the section inside 3 mm to 6 mm from the outermost periphery of the semiconductor wafer in this shape data is a first-order approximate straight line (1 And a profile obtained by subtracting the component of the first-order approximate straight line (primary function) from the fitted profile. A section 3 mm to 6 mm inside from the outermost periphery of the semiconductor wafer is a reference line. This profile is shown in FIG.
16A and 16B, it can be seen that a similar profile can be obtained even if the warpage of the semiconductor wafer changes due to the peeling of the SiO ₂ thin film.

(Comparative Example 2)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
The conditions of Comparative Example 1 are the same except that the section for obtaining the reference line is a section of 10 to 14 mm from the outermost periphery of the semiconductor wafer.
FIG. 17A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 17B shows the profile of the semiconductor wafer after peeling off the SiO ₂ thin film.
17 (A) and 17 (B), it can be seen that the profile differs due to the change in the warp of the semiconductor wafer due to the peeling of the SiO ₂ thin film.

(Comparative Example 3)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
The conditions for Comparative Example 1 are the same except that the section for obtaining the reference line is a section of 3 to 27 mm from the outermost periphery of the semiconductor wafer.
FIG. 18A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 18B shows the profile of the semiconductor wafer after peeling off the SiO ₂ thin film.
Comparing FIG. 18A and FIG. 18B, it can be seen that the profile differs due to the change in the warpage of the semiconductor wafer due to the peeling of the SiO ₂ thin film.

(Evaluation of Comparative Examples 1 to 3)
In Comparative Example 1, the same profile could be obtained even when the warpage of the semiconductor wafer changed, but in Comparative Examples 2 and 3, the profiles were completely different before and after the SiO ₂ thin film was peeled off from the semiconductor wafer. It is had. That is, in the conventional shape characteristic acquisition method, it can be confirmed that the shape characteristic of the outer peripheral portion may not be obtained accurately depending on the position and length of the section where the reference line is obtained by fitting the shape data. It was. Accordingly, it has been confirmed that it is difficult to accurately obtain the shape characteristics of the outer peripheral portion of the semiconductor wafer.

(Comparative Example 4)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
First, the shape data of the surface of the semiconductor wafer before peeling off the SiO ₂ thin film was obtained. Next, in this shape data, a section 10 mm to 14 mm inside from the outermost periphery of the semiconductor wafer was fitted with a quadratic approximate curve (quadratic function) obtained using the least square method. Thereafter, a profile obtained by subtracting the component of the quadratic approximate curve (quadratic function) from the fitted profile was obtained. A section 10 mm to 14 mm inside from the outermost periphery of the semiconductor wafer is a reference line. Such an operation was measured for each predetermined angle along the circumferential direction of the semiconductor wafer, and a profile having a reference line was obtained over the entire outer circumference of the semiconductor wafer. This profile is shown in FIG.

In the same manner, the shape data of the surface of the semiconductor wafer after the SiO ₂ thin film is peeled off is obtained, and the section of the shape data within 10 mm to 14 mm from the outermost periphery of the semiconductor wafer is represented by a quadratic approximate curve (2 And a profile obtained by subtracting the component of the quadratic approximate curve (quadratic function) from the fitted profile. A section 10 mm to 14 mm inside from the outermost periphery of the semiconductor wafer is a reference line. This profile is shown in FIG.
Comparing FIG. 19A and FIG. 19B, it can be seen that the shape of the profile is completely different due to the change in warpage of the semiconductor wafer due to the peeling of the SiO ₂ thin film.

(Comparative Example 5)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
The conditions of Comparative Example 4 are the same except that the section for obtaining the reference line is a section of 3 to 27 mm from the outermost periphery of the semiconductor wafer.
FIG. 20A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 20B shows the profile of the semiconductor wafer after peeling off the SiO ₂ thin film.
20A and 20B are compared, it can be seen that the same profile can be obtained even if the warpage of the semiconductor wafer changes due to the peeling of the SiO ₂ thin film.

(Evaluation of Comparative Examples 4 and 5)
In Comparative Example 5, the same profile could be obtained even if the warpage of the semiconductor wafer changed, but in Comparative Example 4, the profile was completely different before and after the SiO ₂ thin film was peeled off from the semiconductor wafer. Oops. That is, in the conventional shape characteristic acquisition method, it can be confirmed that the shape characteristic of the outer peripheral portion may not be obtained accurately depending on the position and length of the section where the reference line is obtained by fitting the shape data. It was. Accordingly, it has been confirmed that it is difficult to accurately obtain the shape characteristics of the outer peripheral portion of the semiconductor wafer.

(Comparative Example 6)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
First, the shape data of the surface of the semiconductor wafer before peeling off the SiO ₂ thin film is acquired. Next, in this shape data, a section 10 mm to 14 mm inside from the outermost periphery of the semiconductor wafer was fitted with a cubic approximate curve (cubic function) obtained using the least square method. Thereafter, a profile obtained by subtracting the component of the cubic approximate curve (cubic function) from the fitted profile was obtained. A section 10 mm to 14 mm inside from the outermost periphery of the semiconductor wafer is a reference line. Such an operation was measured for each predetermined angle along the circumferential direction of the semiconductor wafer, and a profile having a reference line was obtained over the entire outer circumference of the semiconductor wafer. This profile is shown in FIG.

In the same manner, the shape data of the surface of the semiconductor wafer after the SiO ₂ thin film is peeled off is acquired, and the section within 10 mm to 14 mm from the outermost periphery of the semiconductor wafer in this shape data is represented by a cubic approximation curve (3 And a profile obtained by subtracting the component of the quadratic approximate curve (quadratic function) from the fitted profile. A section 10 mm to 14 mm inside from the outermost periphery of the semiconductor wafer is a reference line. This profile is shown in FIG.
Comparing FIG. 21A and FIG. 21B, it can be seen that the shape of the profile becomes completely different due to the change in warpage of the semiconductor wafer due to the peeling of the SiO ₂ thin film.

(Comparative Example 7)
A conventional method for obtaining shape characteristics of the outer periphery of a semiconductor wafer was performed.
The conditions of Comparative Example 6 are the same except that the section for obtaining the reference line is a section of 3 to 27 mm from the outermost periphery of the semiconductor wafer.
FIG. 22A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 22B shows the profile of the semiconductor wafer after peeling off the SiO ₂ thin film.
Comparing FIGS. 22A and 22B, even if the warpage of the semiconductor wafer is changed due to the peeling of the SiO ₂ thin film, the same profile can be obtained and the same shape characteristic can be obtained. I understand that I can do it.

(Evaluation of Comparative Examples 6 and 7)
In Comparative Example 7, the same profile could be obtained even if the warpage of the semiconductor wafer changed, but in Comparative Example 6, the profile was completely different before and after the SiO ₂ thin film was peeled off from the semiconductor wafer. Oops. That is, in the conventional shape characteristic acquisition method, it can be confirmed that the shape characteristic of the outer peripheral portion may not be obtained accurately depending on the position and length of the section where the reference line is obtained by fitting the shape data. It was. Accordingly, it has been confirmed that it is difficult to accurately obtain the shape characteristics of the outer peripheral portion of the semiconductor wafer.

According to the comparative examples 1 to 7 described above, in the conventional shape characteristic acquisition method, the position and length of the section in which the shape data is fitted to obtain the reference line are influenced by the warp, and also by the function to be fitted, It has been found that accurate shape characteristics of the outer peripheral portion may not be obtained.
On the other hand, in Examples 1 to 3, the shape characteristics of the outer peripheral portion of the semiconductor wafer can be accurately obtained even if the length and position of the section for obtaining the reference line are changed without being affected by the warp. I knew it was possible.

  The present invention can be used to acquire the shape and characteristics of the outer peripheral portion of a semiconductor wafer.

It is a block diagram which shows the measuring apparatus for acquiring the shape characteristic of the outer peripheral part of the semiconductor wafer concerning embodiment of this invention. FIG. 2A is a diagram showing shape data of the front and back surfaces along the radial direction of the semiconductor wafer. FIG. 2B is a diagram showing the shape data and the center line of the thickness of the semiconductor wafer. FIG. 3C is a diagram showing the shape data, the center line, and the reference curve, and FIG. 3D is a diagram showing a profile obtained by removing the components of the reference curve. FIG. 4E is a diagram illustrating a profile of the front surface of the semiconductor wafer including the reference line, and FIG. 4F is a diagram illustrating a profile of the back surface of the semiconductor wafer including the reference line. It is a flowchart which shows the shape characteristic acquisition method of the outer peripheral part of a semiconductor wafer. FIG. 6A is a diagram showing shape data of the front and back surfaces along the radial direction of the semiconductor wafer, and FIG. 6B is a diagram showing the shape data and the center line of the thickness of the semiconductor wafer. FIG. 7C is a diagram illustrating the shape data, the center line, and the reference curve, and FIG. 7D is a diagram illustrating a profile from which the components of the reference curve are removed. FIG. 8E is a diagram showing a profile of the surface of the semiconductor wafer including the reference line, and FIG. 8F is a diagram showing a profile of the back surface of the semiconductor wafer including the reference line. FIG. 9A is a diagram showing shape data of the front and back surfaces along the radial direction of the semiconductor wafer, and FIG. 9B is a diagram showing the shape data and the center line of the thickness of the semiconductor wafer. FIG. 10C is a diagram showing the shape data, the center line, and the reference curve, and FIG. 10D is a diagram showing a profile obtained by removing the components of the reference curve. FIG. 11E is a diagram showing a profile of the surface of the semiconductor wafer including the reference line, and FIG. 11F is a diagram showing a profile of the back surface of the semiconductor wafer including the reference line. FIG. 12A is a diagram showing the shape data and warpage of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 12B is the shape data of the semiconductor wafer after peeling off the SiO ₂ thin film and It is a figure which shows curvature. Shows the results of Example 1, FIG. 13 (A) shows a profile of the semiconductor wafer before peeling the thin SiO ₂ film, and FIG. 13 (B), the semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. FIGS. 14A and 14B show the results of Example 2, in which FIG. 14A shows the profile of the semiconductor wafer before peeling off the SiO ₂ thin film, and FIG. 14B shows the semiconductor wafer after peeling off the SiO ₂ thin film. The profile of is shown. Example shows the results of the 3, FIG. 15 (A) shows a profile of the semiconductor wafer before peeling the thin SiO ₂ film, FIG. 15 (B) is a semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 1, FIG. 16 (A) shows a profile of the semiconductor wafer before peeling the SiO ₂ thin film, FIG. 16 (B) semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 2, FIG. 17 (A) shows a profile of the semiconductor wafer before peeling the SiO ₂ thin film, FIG. 17 (B) is a semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 3, FIG. 18 (A) shows a profile of the semiconductor wafer before peeling the thin SiO ₂ film, and FIG. 18 (B) is a semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 4, FIG. 19 (A) shows a profile of the semiconductor wafer before peeling the thin SiO ₂ film, 19 (B) is a semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 5, FIG. 20 (A) shows a profile of the semiconductor wafer before peeling the SiO ₂ thin film, FIG. 20 (B) semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 6, FIG. 21 (A) shows the profile of the semiconductor wafer before peeling the SiO ₂ thin film, FIG. 21 (B) semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. Shows the results of Comparative Example 7, FIG. 22 (A) shows a profile of the semiconductor wafer before peeling the SiO ₂ thin film, FIG. 22 (B) semiconductor wafer after removal of the SiO ₂ thin film The profile of is shown. It is a schematic diagram which shows the shape characteristic acquisition method of the outer peripheral part of the conventional semiconductor wafer. It is a figure which shows the detail of the shape characteristic acquisition method of the outer peripheral part of the conventional semiconductor wafer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Measuring apparatus 2 Semiconductor wafer 11 Shape measuring apparatus 12 Shape characteristic acquisition apparatus 20 Profile 21 Shape data 21A Shape data 21B Shape data 22 Approximate curve 23 Reference line 24 Center line 25 Reference curve 26 Profile 26A Profile 26B Profile 27 Reference line 28 Profile 28A Profile 28B Profile 121 Storage unit 122 Calculation unit 122A Midpoint calculation unit 122B Reference curve calculation unit 122C Profile acquisition unit 122D Analysis unit H Chamfering portion T Deviation amount T1 Deviation amount T2 Deviation amount

Claims (4)

A shape characteristic acquisition method for acquiring a shape characteristic of an outer peripheral portion of a semiconductor wafer,
A shape data acquisition step for acquiring shape data along the radial direction of the front and back surfaces of the semiconductor wafer;
A midpoint calculation step of calculating the midpoint of the thickness of the semiconductor wafer from the shape data of the front and back surfaces of the semiconductor wafer acquired in the shape data acquisition step;
A reference curve calculating step of calculating a reference curve which is a quadratic approximate curve from the midpoint;
A profile acquisition step for obtaining a profile obtained by removing the component of the reference curve from the shape data of the front surface and / or the back surface of the semiconductor wafer;
After fitting a predetermined section of the profile excluding the outer peripheral portion of the semiconductor wafer with a linear function, a component of the linear function is subtracted from the fitted profile, and the predetermined section becomes a reference line with almost no displacement. And
A shape characteristic obtaining method comprising: obtaining a shape characteristic of the outer peripheral portion of the semiconductor wafer by obtaining a deviation amount at a predetermined position of the outer peripheral portion of the semiconductor wafer with respect to the reference line. In the shape characteristic acquisition method according to claim 1,
A shape characteristic acquisition method comprising removing a roughness component of shape data on the front surface and / or back surface of the semiconductor wafer by moving average processing before the profile acquisition step. From the shape data of the front and back surfaces of the semiconductor wafer along the radial direction, a midpoint calculation step for calculating the midpoint of the thickness of the semiconductor wafer,
A reference curve calculating step of calculating a reference curve which is a quadratic approximate curve from the midpoint;
A profile acquisition step for obtaining a profile obtained by removing the component of the reference curve from the shape data of the front surface and / or the back surface of the semiconductor wafer;
After fitting a predetermined section of the profile excluding the outer peripheral portion of the semiconductor wafer with a linear function, a component of the linear function is subtracted from the fitted profile, and the predetermined section becomes a reference line with almost no displacement. And
A program for causing a computer to execute a shape characteristic obtaining step for obtaining a shape characteristic of an outer peripheral portion of the semiconductor wafer by obtaining a deviation amount at a predetermined position of the outer peripheral portion of the semiconductor wafer with respect to the reference line.   A recording medium storing the program according to claim 3.

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