JP3620891B2 - Thin film evaluation apparatus and thin film evaluation method - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a substrate shape measuring method and apparatus for measuring the shape of a substrate from an obtained image by using a CCD and a moving stage, and more particularly to an opening in a substrate required for characteristic evaluation of a thin film on a mask used for a display or the like. The present invention relates to a substrate shape measuring method and apparatus for accurately determining the size of the hole.
[0002]
[Prior art]
In general, in the field of measurement, to accurately measure the shape of an object, for example, the length of the side of a square hole, the diameter of a circular hole, or the substantial size of an arbitrarily shaped hole. Is often required. In particular, along with other measurements, the size of the hole is often an important factor as a correction term or as a constituent factor for characteristic calculation.
For example, as a method for evaluating the physical properties of a thin film formed by vapor deposition, sputtering, CVD, ion plating, or the like, it may be performed by measuring the amount of deflection by applying a differential pressure. An evaluation device has been developed that automatically measures and computes. However, in such a thin film evaluation method, since the amount of deflection of the thin film material depends on the size of the hole covered by the thin film, the size of the hole forms an important factor. It is necessary to give to.
[0003]
In such a case, as a method of measuring the shape of the hole in the thin film material,
(1) Measure directly with a ruler,
(2) Place the sample under the microscope, check the edge position with the naked eye, rotate the sample so that the edge is perpendicular to the stage moving direction, move the stage and detect the edge again. And measure this as the width of the sample,
(3) The image of the entire thin film is captured by a CCD and the shape dimensions are obtained by image processing technology.
Etc. were common.
[0004]
[Problems to be solved by the invention]
However, it is natural that the thin film evaluation system is configured with a computer equipped with an appropriate program, so the acquisition of the exact numerical values required for the calculation and substitution into the formula is automatic. The demand to do is increasing. However, in the above methods (1) and (2), since the measurer must always intervene, automatic measurement cannot be performed, and an error based on the subjectivity of the measurer is included. In the method (2), the algorithm for determining the moving direction of the stage is complicated and is not suitable for automation. Furthermore, in the method (3), the accuracy required for evaluating the thin film characteristics cannot be reached because the number of CCD pixels that capture the entire image dominates the accuracy.
An object of the present invention is to provide a measurement method based on a simple algorithm that enables automatic measurement, and to provide a measurement apparatus with sufficient resolution. Another object of the present invention is to provide a shape measuring method and apparatus that can be used by being incorporated in a thin film evaluation apparatus for evaluating the physical properties of a thin film in a hole portion of a substrate.
[0005]
[Means for Solving the Problems]
In order to achieve the above object, the shape measuring method of the present invention mounts a sample having different brightness portions surrounded by a closed curve on an XY stage moving in two axes, and the sample is placed on the CCD matrix by an objective lens. The position of one end of the portion surrounded by the closed curve is specified by the coordinates of the CCD matrix, and the XY stage is moved to project an image of the other end of the portion surrounded by the closed curve onto the CCD matrix. The position of the end is specified by the coordinates of the CCD matrix, and the size of the portion surrounded by the closed curve is calculated from the coordinates of the CCD matrix corresponding to the ends of the holes and the movement amount of the XY stage. Features.
[0006]
Further, in the substrate shape measuring method of the present invention, when the portion with different brightness in the sample is a square hole, after the position of the first end of the hole is specified by the coordinates of the CCD matrix, The position of the second end is specified by the coordinates of the CCD matrix so that the second end of the hole is projected onto the CCD matrix by moving in the axial direction, and the XY stage is moved in the axial direction perpendicular to the previous axis. Then, the position of the hole is projected by the CCD matrix so that the third end of the hole is projected onto the CCD matrix, and the length of the side of the square is determined based on the coordinates of the CCD matrix and the amount of movement of the XY stage. Can be calculated.
[0007]
Furthermore, when the part with different brightness in the sample is a circular hole, the position of the first end and the second end of the hole is specified by the coordinates of the CCD matrix by moving the XY stage in one axial direction. Then, the midpoint of the first end and the second end is calculated based on the coordinates of the CCD matrix and the movement amount of the XY stage, the XY stage is returned to the vicinity of the midpoint, and the XY stage is further moved in another axial direction. The third end and the fourth end at which the perpendicular formed at the midpoint of the first end and the second end intersects the hole are specified by the coordinates of the CCD matrix, and the coordinates of the CCD matrix and XY The midpoint of the third end and the fourth end can be calculated based on the moving amount of the stage so as to be the center of the circular hole.
[0008]
Furthermore, even when the portion with different brightness in the sample is an irregular hole, it is moved in the first axial direction of the XY stage so that the positions of the first end and the second end of the hole are in the coordinates of the CCD matrix. Further, the width of the hole in the first axis direction is calculated based on the amount of movement of the XY stage, and then the XY stage is repeatedly moved in a predetermined increment in the second axis direction perpendicular to the previous axis. The width of the direction can be calculated, and the calculated widths can be integrated to calculate the dimensions of the irregular holes.
[0009]
The substrate shape measuring apparatus according to the present invention includes an XY stage that mounts a sample having a hole and moves in two axes, and a CCD matrix in which the XY axis and XY axis directions of the XY stage coincide with each other. A CCD camera that generates an electrical signal corresponding to the light intensity of the image, a lens barrel that includes an objective lens that projects an image of the sample on the image receiving surface of the CCD camera, and receives the output of the CCD camera to characterize the image. An image processing device that detects and outputs, and an arithmetic processing device that receives the output of the image processing device and the amount of movement of the XY stage and outputs a value corresponding to the size of the hole.
[0010]
Furthermore, a thin film evaluation apparatus according to the present invention includes an XY stage on which a thin film sample is mounted, a microscope barrel that enlarges an image of the sample and projects it onto the imaging surface of the probe, a probe that acquires sample shape information, and a probe A first image processing device that calculates the deflection of the sample by processing a signal from the image processing device, and an arithmetic processing device that inputs a detection signal from each detector and performs an arithmetic processing to evaluate a physical property of the sample. A CCD photo detector that captures an enlarged image of the sample through the microscope lens tube and converts it into an electrical signal, and an image signal from the CCD photo detector is input to extract a portion having a brightness difference in the sample image And a second image processing apparatus that calculates a dimension of the sample from the output of the second image processing apparatus and the amount of movement of the XY stage, and includes it in the physical property evaluation of the sample.
[0011]
[Action]
According to the shape measuring method of the present invention, the image of the sample is magnified by the objective lens and projected onto the CCD light receiving surface, so the resolution for specifying the position of the sample is governed by the physical CCD matrix quantity and density. Instead, it is possible to obtain high positional accuracy as required. Further, since the amount of movement of the XY stage that moves in the X-axis direction or the Y-axis direction with the sample mounted thereon can be grasped with high accuracy in the prior art, the measurement accuracy of the position of the sample is extremely high. Furthermore, it is easy to automate the entire measurement procedure, and an accurate value can be obtained by simple image processing. Therefore, for example, it is easy to incorporate and use in a thin film evaluation apparatus.
[0012]
In addition, when the measurement target portion in the sample has a predetermined shape such as a square or a circle, the measurement procedure and the arithmetic processing can be greatly simplified.
Furthermore, even when the shape of the object to be measured is indefinite, it can be measured mechanically by a simple repetitive operation, so that an apparatus for carrying out the method of the present invention can be easily obtained.
[0013]
According to the shape measuring apparatus of the present invention, it is obtained based on the amount of movement of the XY stage that can be accurately grasped and a CCD matrix that can give a substantially high resolution by enlarging and projecting the sample with a lens. Since the shape is measured using coordinate values, the measurement accuracy is sufficient for evaluating the thin film characteristics. Further, according to the shape measuring apparatus of the present invention, automatic measurement is possible.
[0014]
In addition, according to the thin film evaluation apparatus according to the present invention, it is not necessary to manually set the shape parameters in advance for the physical property evaluation of the thin film, and the measured value at the time of evaluation can be used, so the reliability of the physical property evaluation is also improved. There are additional benefits.
In addition, by utilizing existing components such as XY stages, microscope barrels, and arithmetic devices that were also used in conventional thin film evaluation equipment, it is possible to incorporate a part that measures the shape of the hole part of the substrate. An increase in the manufacturing cost of the entire thin film evaluation apparatus incorporating the apparatus can be suppressed.
[0015]
【Example】
FIG. 1 is a conceptual explanatory view showing a first embodiment of a shape measuring apparatus according to the present invention. The measuring device measures the dimension of a square, a perfect circle, or a hole having a certain shape, which a substrate such as a silicon wafer has.
In the figure, 1 is a sample to be measured, 2 is an XY stage that mounts the sample and moves in two axes, 3 is a surface plate that mounts an XY stage, 4 is a lens barrel with an objective lens, 5 is a CCD camera, 6 is an image processing device, 7 is an arithmetic processing device, and 8 is a stage controller.
[0016]
The sample 1 includes a substrate 1-1 having a hole 11 and a thin film 1-2 formed so as to cover the hole 11, and a portion of the hole 11 below the thin film 1-2 is a portion 12 of the surrounding meat. It can be distinguished because the brightness is different. The objective lens 41 of the lens barrel 4 enlarges the image of the hole 11 and projects it on the image receiving surface of the CCD camera 5. The CCD camera 5 electrically converts the projection image of the holes 11 by photoelectric elements arranged in a matrix and transmits image information indicating the presence or absence of light reception for each element to the image processing device 6. The image processing apparatus 6 evaluates the electrical output at each element position, and determines the meat portion 12 and the hole 11 portion of the image projected on the CCD matrix. The arithmetic processing device 7 receives the determination signal from the image processing device 6 and performs arithmetic processing, and may be a personal computer, for example. The arithmetic processing in the arithmetic processing unit 7 obtains coordinate values in the CCD matrix for the edge of the hole 11, that is, the boundary between the meat portion 12 and the hole 11, and controls the stage controller 8 based on the result to control the XY stage. Move 2 appropriately. The arithmetic processing unit 7 calculates the dimension of the hole 11 using the movement amount of the XY stage 2 and the coordinate value of the edge of the hole 11 acquired again after moving the XY stage 2 together with the previously acquired coordinate value. The XY axes of the CCD matrix are adjusted so as to coincide with the XY axes of the XY stage 2.
[0017]
Measurement using the above measuring apparatus is performed as follows. First, the sample 1 is placed on the XY stage 2 and the lens barrel 4 is adjusted so that the image of the sample 1 is enlarged and formed on the light receiving surface of the CCD camera 5. Whether the projected image is the meat portion 12 or the hole 11 portion of the sample can be determined by comparing the output of the CCD element with an appropriate threshold value. Further, the XY stage 2 is appropriately adjusted so that a part of the edge of the hole 11 in the sample 1 is projected onto the CCD matrix surface of the CCD camera 5. The operator may make adjustments based on the image displayed on the monitor so that the edge portion is present in the image. For example, the position where the black area and the white area in the image are equal is found. It is also possible to detect an edge by a simple image processing method, such as a method of finding the presence of an edge, or a method of monitoring an intensity change along an appropriate line and recognizing the edge from a position where the intensity changes drastically. . If such an automatic detection method is used, by adjusting the XY stage 2 via the arithmetic processing unit 7, the edge can be automatically moved to a position where it exists in the image.
[0018]
Here, for example, the vertical direction of the screen is the Y-axis direction, the horizontal direction of the screen is the X-axis direction, the lower left corner of the screen is the origin, the maximum coordinate value in the Y-axis direction in the screen is Ym, and the X-axis direction in the screen is The maximum coordinate value is defined as Xm.
FIG. 2 is a diagram for explaining a calibration method for making the coordinates on the screen correspond to the actual size. FIG. 2A is a diagram for explaining the X axis, and FIG. 2B is a diagram for explaining the Y axis. As known from FIG. 2A, the X stage is moved by a known distance Mx in the X-axis direction so that an image appears on the screen, and a certain point moves on the X coordinate in the screen. The amount ΔX is obtained. Then, the distance Dx on the surface of the sample 1 corresponding to Xm indicating the width of the coordinate value on the screen is obtained by Equation 1 from the X-axis direction movement amount Mx of the X stage and the X coordinate difference ΔX at an arbitrary Y position. be able to. Also, as is apparent from FIG. 2B, the distance Dy on the surface of the sample 1 corresponding to Ym is the difference in the Y coordinate at an arbitrary X position when the Y stage is moved by My in the Y-axis direction. It can obtain | require by Numerical formula 2 from (DELTA) Y.
[0019]
[Expression 1]
Dx = Mx · Xm / ΔX
[Expression 2]
Dy = My · Ym / ΔY
[0020]
First, a method for obtaining the side length D when the hole 11 of the sample 1 is square will be described. FIG. 3 is a diagram for explaining a method for obtaining the side length of a square hole.
Assuming that the edge of the square hole 11 appears on the screen by the initial adjustment, the X coordinate of the edge P1 of the hole 11 at an appropriate coordinate Y1 in the Y-axis direction is X1. Further, an angle θ formed by the direction in which the edge of the hole 11 extends with respect to the X axis is obtained.
Next, the X stage of the XY stage 2 on which the sample 1 is mounted is moved in the X-axis direction and the direction in which the area of the hole 11 increases, and a screen in which the edge P2 on the opposite side of the hole 11 appears at the position of the coordinate Y1 is acquired. Like that. Here, the X coordinate X2 of the edge of the hole 11 at the Y coordinate Y1 is read. If the amount of movement of the X stage at this time is Lx, Lx can be accurately known from the signal acquired from the stage controller 8 that controls the movement of the XY stage 2. Note that the stage actually used in the apparatus is not always driven continuously due to mechanical or operational problems, but the movement is intermittent if the amount of movement can be accurately grasped. May be.
Further, this time, the Y stage of the XY stage 2 is moved in the Y-axis direction and the direction in which the area of the hole 11 is expanded so that the edge P3 on the opposite side of the hole 11 appears again at the position of the coordinate X2. The amount of movement of the Y stage at this time is Ly. Then, the Y coordinate Y2 of the edge of the hole 11 at the coordinate X2 is read.
When P2 is on the side adjacent to the side where P1 exists, the side length D of the square is the sum of the sine of side P1P2 and the cosine of side P2P3 as apparent from FIG. Can be sought. Needless to say, when the point P2 is the opposite side of the side where P1 exists, the side length D is obtained only by the first term of Equation 3.
[0021]
[Equation 3]
D = (Lx + Dx · (X2−X1) / Xm) sin θ + (Ly + Dy · (Y2−Y1) / Ym) cos θ
[0022]
Next, a method for obtaining the diameter of a circle when it is known in advance that the hole 11 is a perfect circle will be described. FIG. 4 is a diagram for explaining a method for obtaining the diameter of a circular hole.
Assuming that the edge of the circular hole 11 appears in the screen by the initial adjustment, the X coordinate of the edge P1 of the hole 11 at an appropriate coordinate Y1 in the Y-axis direction is set to X1.
Next, the X stage of the XY stage 2 on which the sample 1 is mounted is moved in the X-axis direction and the direction in which the area of the hole 11 increases, and a screen in which the edge P2 on the opposite side of the hole 11 appears at the position of the coordinate Y1 is obtained. Then, the coordinate X2 of the edge of the hole 11 at the coordinate Y1 is read. The amount of movement of the X stage at this time is Lx.
[0023]
Next, the distance Dh to the midpoint Ph between the two edges P1 and P2 is obtained by Equation 4, and the X stage is returned by approximately Dh in the reverse direction on the X axis so that the Ph point is within the screen. Therefore, the X-axis coordinate value Xh of the Ph point in the new screen is obtained from the actual movement amount Lh of the X stage and the coordinate value X2 previously obtained for the point P2.
[0024]
[Expression 4]
Dh = (Lx + Dx · (X2−X1) / Xm) / 2
[0025]
Further, the Y stage of the XY stage 2 is moved in the Y axis direction so that the edge P3 of the hole 11 appears at the position of the coordinate Xh, and the Y coordinate Y3 of the edge P3 at the coordinate Xh in the screen is read.
Next, the Y stage is moved in the opposite direction on the Y axis to obtain a screen in which the edge P4 on the opposite side of the circular hole 11 appears at the position of the X coordinate Xh, and the edge P4 at the X coordinate Xh is acquired. The Y coordinate Y4 is read. If the amount of movement of the Y stage at this time is Lm, the radius R of the circular hole 11 is given by Equation 5.
[0026]
[Equation 5]
R = (Lm + Dy. (Y3-Y4) / Ym) / 2
[0027]
Therefore, the position of the center O of the hole 11 is at the X coordinate Xh and the Y coordinate Yo in the screen obtained by returning the Y stage substantially by the distance R in the Y-axis direction, actually Lr. However, Yo is a value given by Equation 6.
[0028]
[Formula 6]
Yo = Y4 + Ym · (R−Lr) / Dy
[0029]
If the XY stage 2 is adjusted using the coordinates (Xh, Yo) of the center O of the hole 11 obtained as described above, it is easy to align the center O of the hole 11 with a desired position in the screen.
[0030]
Next, a method for obtaining the area of the hole when the hole 11 is indefinite will be described with reference to FIG.
In the conventional method, since the entire area was captured by the CCD and the area of the hole was evaluated from the total number of the CCD elements in which the hole was detected, the measurement accuracy was governed by the total number and density of the CCD matrix, High accuracy could not be expected.
In contrast, the measurement method of the present invention employs an XY stage as a sample stage on which a sample is mounted, manages the stage movement during measurement, and uses the movement amount for image evaluation. Therefore, the screen position of the CCD camera is quantified. Therefore, it is not necessary to image the entire hole on one screen of the CCD camera, and the range that the CCD camera can capture images is enlarged with a lens, so that the substantial resolution for the object is increased and the accuracy is improved. Can be improved.
[0031]
First, the XY stage 2 is adjusted appropriately so that a part of the edge of the hole 11 in the sample 1 is projected onto the CCD matrix surface of the CCD camera 5. The X coordinate of the edge P1 of the hole 11 at an appropriate Y coordinate Y1 is X1, and the X coordinate of the edge P2 at a slightly separated Y coordinate Y2 is X2.
The average value of these coordinate values is used as the edge coordinates of this portion. This is because the edge of the hole 11 does not necessarily draw a smooth curve, and the coordinates required for one point on the edge may be a singular point that does not represent a substantial hole outline.
Next, the X stage of the XY stage 2 on which the sample 1 is mounted is moved in the X-axis direction and the direction in which the area of the hole 11 expands, and a screen in which the edge P3 opposite to the hole 11 appears at the position of the coordinate Y1 is obtained. To do. The amount of movement of the X stage at this time is L. Here, the X coordinate X3 of the edge P3 of the hole 11 at the Y coordinate Y1 is read. Further, the X coordinate of the edge P4 corresponding to the Y coordinate Y2 is read and set as X4. As before, these average values are used as the coordinates of the edge of this part.
The width D of the hole 11 at the position of the Y coordinate Y1Y2 is expressed by Equation 7 using the above value.
[0032]
[Expression 7]
D = L + Dx · ((X3 + X4) / 2− (X1 + X2) / 2) / Xm)
[0033]
In order to obtain the area of the entire hole 11, the width in the X-axis direction is calculated and integrated by the above method while the Y coordinate value is incremented by an appropriate constant amount over the entire width in the Y-axis direction of the hole 11, What is necessary is just to multiply the step width of the said Y-axis direction.
[0034]
FIG. 6 is a block diagram showing an example in which the shape measuring apparatus of the present invention is used by being incorporated in a thin film evaluation apparatus. The thin film evaluation apparatus is for evaluating physical properties of a thin film formed on a substrate.
FIG. 7 is a drawing for explaining a thin film evaluation method in a thin film evaluation apparatus incorporating a shape measuring device. According to this method, the amount h of deflection of the thin film when the differential pressure p is applied to the thin film F by measuring the sample in which the thin film F is formed on the silicon wafer S having the hole so as to cover the hole is measured. Evaluation is made based on the internal stress σ and Young's modulus E calculated by Equations 8, 9, and 10 using the measured values. Here, ν is the Poisson's ratio, t is the thickness of the thin film, r is an index representing dimensions such as the diameter and length of the holes, and A and B are intermediate variables.
[0035]
[Equation 8]
p = A ・ h + B ・ h³
[Equation 9]
A = tσ / r²
[Expression 10]
B = 3tE / 8r⁴(1-ν)
[0036]
In order to evaluate the thin film using this formula, it is necessary to separately obtain the thickness r of the thin film and the value r representing the dimension of the hole. Moreover, since r is included as a quadratic and quartic function in the mathematical expression, the error greatly affects the accuracy of the required internal stress and Young's modulus.
Therefore, the shape measuring device of the present invention is incorporated in the thin film evaluation device, and the shape of the hole is accurately and automatically measured simultaneously with the evaluation measurement, and the result is taken into the evaluation formula to obtain the accurate physical property value. It is a thing.
[0037]
In FIG. 6, 21 is a silicon substrate on which a thin film to be measured is formed, 22 is an XY stage on which a silicon substrate that is a sample is mounted, 23 is a surface plate that holds the movable part so as not to vibrate, and 24 is an image of the sample. Microscope tube for enlarging and projecting onto the imaging surface of the detection apparatus, 25 for a CCD photo detector for taking an image of a sample and converting it into an electrical signal, and 26 for inputting a video signal from the CCD photo detector for signal processing An image processing device 27 that generates valid image information by inputting detection signals from the detectors, processes the signals, supplies appropriate operation signals to the control devices, and outputs necessary measurement values to a display or a printer. A personal computer 28 is a stage controller that controls the XY stage 22 so as to be suitable for measurement so that the measurement target is located at a necessary position.
[0038]
In FIG. 6, reference numeral 31 denotes a probe that acquires the deformation of the thin film as secondary plane information by light wave interferometry, 32 denotes an image processing apparatus that calculates a distribution of the deformation of the thin film by processing a signal from the probe 31, and 33 denotes a sample 21. And a vacuum pump controller for controlling the vacuum applied to the thin film mounted on the vacuum chamber according to a command from the personal computer 27, and 35 applied to the vacuum chamber 33. It is a vacuum gauge that measures the degree of vacuum.
[0039]
First, the sample 21 whose hole is covered with a thin film is mounted so that the thin film forming surface faces up and the hole part hits the vacuum opening of the vacuum chamber 33, and the meat part of the silicon substrate is vacuumed by a separate vacuum chuck device. The substrate is held in a vacuum chamber by suction. The vacuum chuck is structured such that when a measurement vacuum is applied to the hole portion, the vacuum is not broken from the surroundings.
Next, the sample 21 is scanned roughly so that the holes in the sample come within the field of view of the CCD photodetector. Therefore, by using the coordinate value in the field of view of the CCD matrix and the movement amount of the XY stage 22 by the method described above, the hole size r such as the hole diameter or the side length, that is, the numerical value r used in the equations 9 and 10. Ask for.
Next, the XY stage 22 is adjusted by the action of the stage controller 28 based on the command from the personal computer 27 so that the center of the target hole is near the center of the field of view of the probe 31.
[0040]
Next, thin film evaluation is performed. First, at atmospheric pressure, the distance from a suitable reference plane to the surface of the thin film at the hole portion is measured. Next, the determined vacuum is generated in the vacuum chamber 33 under the control of the vacuum pump controller 34. The degree of vacuum is measured with a vacuum gauge and transmitted to an arithmetic unit for use in an evaluation formula. The difference between the vacuum and the atmospheric pressure is the differential pressure p applied to the thin film. When the distance to the thin film is measured in a state where the pressure p is applied in this way, the difference from the previously obtained distance under the atmospheric pressure becomes the deflection amount h of the thin film used in Equation 8. The thin film evaluation apparatus can determine the maximum deflection amount from the measurement result of the secondary plane. Needless to say, when the center position of the hole is given in advance, the deflection amount h used in the equation can be obtained easily and accurately by direct measurement at the center position.
[0041]
When the degree of vacuum is changed, the above-described deflection amount is measured again, and two sets of measured values are substituted into Equation 8, coefficients A and B are obtained. Therefore, by substituting known numerical values into Equation 9 and Equation 10, the internal stress σ and Young's modulus E of the thin film can be obtained, and thereby the physical properties of the thin film can be evaluated.
The above procedure can be automatically executed according to a sequence control program incorporated in the personal computer 27.
[0042]
【The invention's effect】
As described above, the shape measuring method and apparatus of the present invention can accurately measure the size of a relatively large hole by using a CCD camera having only a small field of view by using an XY stage.
In addition, when the method and apparatus of the present invention are incorporated into a thin film evaluation apparatus, instead of using a ruler directly to measure, a value such as a hole diameter of a sample is automatically measured with extremely high accuracy, and a thin film evaluation formula Therefore, the physical properties of the sample can be evaluated accurately and quickly. In addition, since the XY stage and the objective lens can be combined with those already attached to the thin film evaluation apparatus, it is very easy to apply the shape measuring apparatus of the present invention.
[Brief description of the drawings]
FIG. 1 is a conceptual explanatory view showing a first embodiment of a shape measuring apparatus according to the present invention.
FIG. 2 is a diagram illustrating a calibration method used in an embodiment of the present invention. 2A is a diagram for explaining the X axis, and FIG. 2B is a diagram for explaining the Y axis.
FIG. 3 is a diagram illustrating a shape measuring method when a hole is square.
FIG. 4 is a diagram for explaining a shape measuring method when a hole is circular.
FIG. 5 is a drawing for explaining a shape measuring method when a hole is indefinite.
FIG. 6 is a block diagram showing an example in which the shape measuring apparatus of the present invention is used in a thin film evaluation apparatus.
FIG. 7 is a drawing for explaining a thin film evaluation method.
[Explanation of symbols]
1,21 samples
2,22 XY stage
3, 23 Surface plate
4, 24
5, 25 CCD camera
6, 26 Image processing device
7, 27 arithmetic processing unit
8, 28 Stage controller
31 Probe
32 Image processing device
33 Vacuum chamber
34 Vacuum pump controller
35 Vacuum gauge

Claims (6)

XY stage for mounting thin film sample, vacuum chamber for applying vacuum from the back side of the sample, microscope barrel for enlarging the image of the sample and projecting it on the imaging surface of the detection device, and obtaining shape information of the sample , A first image processing device for calculating the deflection of the sample by processing a signal from the probe, and an arithmetic processing for inputting the detection signal from each detector and performing an arithmetic processing to evaluate a physical property of the sample A thin film evaluation apparatus comprising:
Furthermore, a CCD photodetector that takes an enlarged image of the sample through the microscope barrel and converts it into an electrical signal, and a video signal from the CCD photodetector is input to determine a brightness difference in the image of the sample. A second image processing device for extracting a portion having
A thin film evaluation apparatus, wherein the dimension of the sample is calculated from the output of the second image processing apparatus and the amount of movement of the XY stage, and is included in the physical property evaluation of the sample. The thin film evaluation apparatus according to claim 1, wherein the physical property evaluation of the sample is based on internal stress and Young's modulus. The thin film evaluation apparatus according to claim 1, wherein the sample is a thin film on a mask. Samples coated with the hole in the thin film possess different portions of lightness surrounded by a closed curve on the XY stage which moves in two axes and mounted in the upper thin film forming surface,
Project an image of the sample onto the CCD matrix by the objective lens,
Adjusting the image of one end of the portion surrounded by the closed curve to be projected onto the CCD matrix, and specifying the position of the end by the coordinates of the CCD matrix;
The XY stage is moved and adjusted so that an image of another end of the portion surrounded by the closed curve is projected onto the CCD matrix, and the position of the other end is specified by the coordinates of the CCD matrix,
Calculate the dimensions of the portion surrounded by the closed curve from the coordinates of the CCD matrix corresponding to the end of the hole and the amount of movement of the XY stage ,
Change the vacuum applied to the sample, measure the maximum amount of deflection in the hole portion,
A thin film evaluation method for evaluating physical properties of a thin film from the differential pressure applied to the film, the maximum amount of deflection of the film, and the above dimensions . 5. The thin film evaluation method according to claim 4, wherein the physical property evaluation of the sample is based on the internal stress and Young's modulus of the film. 6. The thin film evaluation method according to claim 4, wherein the sample is a thin film on a mask.

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