Resistivity measurement method, method for manufacturing a semiconductor device, recording medium, and resistivity measuring device

Abstract

Provided is a technology that includes: a storage unit that stores at least a process for measuring a measurement object and a measurement mode for measuring the measurement object; and a control unit that controls the measurement of the measurement object in such a way that the control unit calculates a predicted time when measurements are made in accordance with the set order of each measurement point set in the process, and changes the set order of each measurement point set in the process according to the measurement mode, calculates the predicted time when measurements are made in accordance with the changed set order, selects the set order with the shortest predicted time among the respectively calculated predicted times, and measures the measurement object in accordance with the selected set order.

Description

Technical Field

[0001] The present disclosure relates to a resistivity measurement method, a method for manufacturing a semiconductor device, a recording medium, and a resistivity measuring device. Background Art

[0002] A resistivity measuring device for a semiconductor wafer is a device for measuring the resistivity of a silicon wafer, the resistivity of an epitaxial wafer formed on the wafer surface, the sheet resistance of a diffusion layer or an implanted layer in the case of impurity diffusion or implantation from the surface, and the sheet resistance of a metal film formed on the surface. The measurement results are fed back to the process conditions of each semiconductor manufacturing device, and this device is one of the important measurement devices for maintaining the quality uniformity of semiconductor elements. As such a measurement device, for example, the content described in Patent Document 1 is available.

[0003] Patent Document 1 describes a four-probe resistivity measuring device for improving the measurement accuracy of the resistivity of a semiconductor wafer.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2013-153021 Summary of the Invention

[0007] When measuring the resistance values of respective points of a semiconductor wafer in the set order of a registered process, depending on the registration method of the process, there is a case where a lot of time is taken until the measurement is completed due to unnecessary operations of the stage portion or the arm portion of the resistivity measuring device.

[0008] An object of the present disclosure is to provide a technique capable of shortening the measurement time of the resistivity of a semiconductor wafer.

[0009] According to one aspect of the present disclosure, there is provided a technique including:

[0010] receiving a process for measuring an object to be measured;

[0011] a first calculation step of calculating a predicted time when measurement is performed in the set order of each measurement point set in the process;

[0012] a second calculation step of changing the set order of each measurement point set in the process according to a measurement mode for measuring the object to be measured, and calculating a predicted time when measurement is performed in the changed set order;

[0013] selecting a process of the set order having the shortest predicted time among the predicted times calculated in the first calculation step and the second calculation step; and

[0014] A step of measuring the analyte according to the selected setting order.

[0015] Advantages of the Invention

[0016] According to the present disclosure, it is possible to shorten the measurement time of the resistivity of a semiconductor wafer. Description of the Drawings

[0017] Figure 1 It is a block diagram showing the configuration of a semiconductor wafer resistivity measuring device according to an embodiment of the present disclosure.

[0018] Figure 2 It is an external view showing the configuration of a probe vertical drive unit, a four-probe probe, a semiconductor wafer, and a measurement stage according to an embodiment of the present disclosure.

[0019] Figure 3 It is a graph showing experimental values representing the relationship between the penetration amount of the probe, the rotation angle of the vertical drive cam, and the cam stress.

[0020] Figure 4 (a) is a schematic plan view for explaining the state before positioning the four-probe probe with respect to the semiconductor wafer disposed on the measurement stage according to an embodiment of the present disclosure. (b) is a schematic plan view for explaining the state after positioning the four-probe probe with respect to the semiconductor wafer disposed on the measurement stage according to an embodiment of the present disclosure.

[0021] Figure 5 (a) of is a view showing the state of being positioned at measurement point 1, (b) is a view showing the state of being positioned at measurement point 2, (c) is a view showing the state of being positioned at measurement point 3, (d) is a view showing the state of being positioned at measurement point 4, and (e) is a view showing the state of being positioned at measurement point 5.

[0022] Figure 6 (a) of is a view showing a process. (b) is a view for explaining measurement mode A in which the process setting order is set as the measurement order.

[0023] Figure 7 It is a flowchart for explaining a method of selecting a measurement order in measurement mode B.

[0024] Figure 8 (a) of is a view showing the state in which the process of (a) of is reordered using measurement mode B. (b) is a view showing (a) on the wafer. Figure 6 (a) of is a view showing the state in which the process of (a) of is reordered using measurement mode B. (b) is a view showing (a) on the wafer.

[0025] Figure 9 It is a flowchart for explaining a method of selecting a measurement order in measurement mode C.

[0026] Figure 10(a) shows the state where the process of Figure 6 (a) has been reordered. (b) is a diagram showing (a) embodied on a wafer.

[0027] Figure 11 It is a diagram explaining the amount of arm movement and the amount of stage movement.

[0028] Figure 12 (a) is a diagram showing measured values and their approximate curves for the relationship between the amount of arm movement and the measurement time. (b) is a diagram showing measured values and their approximate curves for the relationship between the amount of stage movement and the measurement time.

[0029] Figure 13 (a) is a diagram showing an example of a process in which the measurement order in measurement mode C is set. (b) is a diagram showing the state where the process of (a) has been reordered using measurement mode B. (c) is a diagram showing the state where the process of (a) has been reordered using measurement mode C.

[0030] Figure 14 It is a diagram showing an example of a process in which the measurement order in measurement mode A is selected.

[0031] Figure 15 It explains the calculation of Figure 14 the predicted measurement time of measurement mode A in the process of

[0032] Figure 16 It explains the calculation of the predicted measurement time of the process of Figure 14 reordered using measurement mode B.

[0033] Figure 17 It explains the calculation of the predicted measurement time of the process of Figure 14 reordered using measurement mode C.

[0034] Figure 18 It is a diagram showing an example of a process in which the measurement order in measurement mode B is selected.

[0035] Figure 19 It explains Figure 18 the calculation of the predicted measurement time of measurement mode A in the process of

[0036] Figure 20 It explains the calculation of the predicted measurement time of the process of Figure 18 reordered using measurement mode B.

[0037] Figure 21 It explains the calculation of the predicted measurement time of the process of Figure 18 reordered using measurement mode C. Detailed Description

[0038] Hereinafter, an embodiment of the present disclosure will be described with reference to Figures 1 - 21 an illustration.

[0039] As Figure 1 shown, a resistivity measuring device 10 for a semiconductor wafer includes a measuring table 11, a rotation driving unit 13, a four-probe head 14, a measuring unit 15, a head vertical driving unit 16, a head horizontal driving unit 17, an operation unit 18, a display unit 19, a control unit 20, and a power supply unit 21.

[0040] The measuring table 11 is a disk-shaped table portion on which a semiconductor wafer 12 to be measured (the object to be measured) is placed. The rotation driving unit 13 rotates the measuring table 11 and stops it at a specified angle. The four-probe head 14 is a head having four probes that contact the upper surface of the semiconductor wafer 12 placed above the measuring table 11 to measure the resistivity of the semiconductor wafer 12. The measuring unit 15 measures a plurality of measurement items for obtaining the resistivity by supplying a measurement current to the semiconductor wafer 12 using the four-probe head 14.

[0041] The head vertical driving unit 16 is a vertical driving unit that moves the four-probe head 14 in the vertical direction to contact the semiconductor wafer 12. The head horizontal driving unit 17 is a horizontal driving unit that moves the head vertical driving unit 16 and the four-probe head 14 in the radial direction of the measuring table 11, that is, in the diameter direction of the semiconductor wafer 12. By the actions of both the head horizontal driving unit 17 and the rotation driving unit 13, the resistivity at a desired position of the semiconductor wafer 12 can be measured.

[0042] The operation unit 18 inputs a process for specifying the position of a desired measurement point on the upper surface of the semiconductor wafer 12. The display unit 19 displays data such as the measurement point position and the measured resistivity of the result. The control unit 20 includes a CPU and a storage device (storage unit) that stores a control program executed by the CPU, and together with at least a storage unit that stores the process and the measurement mode for measuring the semiconductor wafer 12, constitutes a computer, and drives and controls the rotation driving unit 13, the head horizontal driving unit 17, and the head vertical driving unit 16 according to the process instructed by the operation unit 18 so that the four-probe head 4 contacts the specified measurement point position on the upper surface of the semiconductor wafer 12. The power supply unit 21 supplies power for operating each part of the resistivity measuring device 10. In addition, Figure 1 the operation unit 18 and the display unit 19 are separate, but they may also be combined into one to form an operation display unit. Also, the storage unit is provided in the control unit 20, but the storage unit may also be provided externally.

[0043] In Figure 1Among them, the operation is to bring the four-probe head 14 controlled based on the process input from the operation unit 18 into contact with the upper surface of the semiconductor wafer 12 placed on the measurement table 11, and (using the measurement unit 15) measure the resistivity of the semiconductor wafer 12.

[0044] Next, use Figure 2 Explain the probe vertical drive unit 16. The probe vertical drive unit 16 is composed of a probe mounting fitting 16a, a cam receiver 16b, a counterweight 16c, a vertical drive cam 16d, and a stepping motor 16e.

[0045] The four-probe head 14 is installed on the probe mounting fitting 16a. The cam receiver 16b receives the vertical driving force of the probe integrated with the probe mounting fitting 16a. The counterweight 16c has a sufficient mass to apply a static load in the vertical direction to the probe vertical drive unit 16. The vertical drive cam 16d is connected to the shaft of the stepping motor 16e and is kept in contact with the front end of the cam receiver 16b at all times. Thus, the weight of the probe mounting fitting 16a including the weight of the counterweight 16c is supported on the shaft of the stepping motor 16e. The vertical drive cam 16d has, for example, an eccentric circular cam shape and can move the cam receiver 16b up and down using the rotation angle. The stepping motor 16e is shaft-coupled to the cam receiver 16b supported by the probe mounting fitting 16a and the vertical drive cam 16d supported by a support member independent of the probe mounting fitting 16a, and can rotate or stop at an arbitrary rotation angle position according to the process instructed by the control unit 20.

[0046] According to the above configuration, the probe vertical drive unit 16 can be controlled according to a process having a load applied to the probe suitable for the type of the semiconductor wafer 12 and a probe vertical movement speed, and appropriate contact between the four-probe head 14 and the semiconductor wafer 12 can be achieved. Then, the resistivity of the semiconductor wafer 12 is measured using the measurement unit 15.

[0047] Here, Figure 3 Experimental values showing the relationship between the penetration amount of the probe 14a, the rotation angle of the vertical drive cam 16d, and the spring stress that becomes the load applied to the semiconductor wafer 12 are shown. In addition, the relationship between the penetration amount, the rotation angle of the vertical drive cam 16d, and the load shown by the Figure 3 curve graph is stored in advance in the storage device of the control unit 20 as a control program. In this way, the control unit 20 adjusts the rotation angle of the vertical drive cam 16d so that the four-probe head 14 stops at Figure 3 any position (penetration amount) shown, whereby the load applied by the probe 14a to the semiconductor wafer 12 can be set, and the contact pressure can be arbitrarily controlled in a manner suitable for the surface material of the semiconductor wafer 12.

[0048] Next, a method for measuring the resistivity of the semiconductor wafer 12 by the resistivity measuring device 10 will be described.

[0049] First, the control unit 20 receives the process for specifying the positions of the required measurement points on the upper surface of the semiconductor wafer 12, and accordingly determines the measurement order of multiple measurement points.

[0050] Next, the control unit 20 uses the probe horizontal drive unit 17 to move the probe vertical drive unit 16 and the four-probe probe 14 in the diameter direction of the semiconductor wafer 12. In addition, the control unit 20 uses the rotation drive unit 13 to rotate the measurement stage 11 on which the semiconductor wafer 12 is placed, so that the four-probe probe 14 moves to the desired measurement point position on the semiconductor wafer 12.

[0051] Next, the control unit 20 uses the probe vertical drive unit 16 to lower the four-probe probe 14 according to an arbitrarily set pressing amount, so that the four probes 14a contact the semiconductor wafer 12.

[0052] Next, the control unit 20 determines the contact reference position (the position where the pressing amount is 0.00 mm). This determination means that the control unit 20 monitors the voltage between two of the four probes 14a of the four-probe probe 14 with a voltmeter (in the measurement unit 15), and determines whether the voltage is within 0 mV ± threshold. The control unit 20 sets the timing when the voltage between the two probes is 0 mV as the contact reference position (the position where the pressing amount is 0.00 mm).

[0053] When the voltage value between the two probes is within the threshold, the control unit 20 measures the resistivity.

[0054] In addition, if the voltage value between the two probes is outside the threshold, the control unit 20 raises the four-probe probe 14 and then lowers it again. If even after the four-probe probe 4 is lowered again a specified number of times, the voltage value between the two probes is still outside the threshold, the control unit 20 stops the resistivity measurement. In this case, the control unit 20 displays an alarm indicating the stop of the resistivity measurement on the display unit 19.

[0055] Refer to Figure 4 , and a method for positioning the four-probe probe 14 at the measurement points of the semiconductor wafer 12 arranged on the measurement stage 11 will be described.

[0056] Figure 4(a) shows the measurement mode before positioning with the semiconductor wafer 12 placed on the measurement stage 11. The direction L-L' in which the four-probe probe 14 is moved by the probe horizontal drive unit 17 is set as the reference direction. Usually, the semiconductor wafer 12 is placed such that the notch 12-1 thereof coincides with the reference direction L-L'. Let the rotation center of the measurement stage 11 be O, and the position of the desired measurement point be P. Let the distance between the rotation center O of the measurement stage 11 and the measurement point P be R, and the angle (counterclockwise angle) formed by the line segment OP and the reference direction L-L' be θ.

[0057] Figure 4 (b) shows the measurement mode after positioning. The positioning of the measurement point is performed by the following two operations.

[0058] (1) The four-probe probe 14 is moved by the probe horizontal drive unit 17 to a position that is only away from the rotation center O of the measurement stage 11 by R in the L' direction.

[0059] (2) The measurement stage 11 is rotated only clockwise by θ from the reference direction L-L' by the rotation drive unit 13.

[0060] By these two operations, the four-probe probe 14 is moved directly above the desired measurement point P on the semiconductor wafer 12. These two operations are performed in parallel.

[0061] Next, use Figure 5 to illustrate the positioning of the four-probe probe 14 for multiple measurement points.

[0062] In Figure 5 (a), the four-probe probe 14 is positioned at the measurement point 1. For example, let the (R, θ) of the measurement points 1, 2, 3, 4, and 5 on the semiconductor wafer 12 shown in Figure 5 (a) be (10, 0), (100, 180), (140, 45), (100, 225), and (10, 45) respectively. Here, the unit of R is mm and the unit of θ is degree.

[0063] When moving the positioning from the measurement point 1 shown in Figure 5 (a) to the measurement point 2, as shown in Figure 5 (b), the measurement stage 11 is rotated clockwise by 180 degrees, and the four-probe probe 14 is moved 90 mm outward in the radial direction. When moving the positioning from the measurement point 2 shown in Figure 5 (b) to the measurement point 3, as shown in Figure 5 (c), the measurement stage 11 is rotated clockwise by 135 degrees, and the four-probe probe 14 is moved 40 mm outward in the radial direction. When moving the positioning from the measurement point 3 shown in Figure 5 (c) to the measurement point 4, as shown inFigure 5 As shown in (d) thereof, the measurement stage 11 rotates clockwise by 180 degrees, and the four-probe head 14 moves 40 mm toward the radial center side. When moving the positioning from Figure 5 the measurement point 4 shown in (d) to the measurement point 5, as Figure 5 shown in (e) thereof, the measurement stage 11 rotates clockwise by 180 degrees, and the four-probe head 14 moves 90 mm toward the radial center side.

[0064] Sometimes, due to the positional relationship of multiple measurement points and the movement order between the measurement points, the measurement stage 11 of the resistivity measuring device 10 and the arm of the probe horizontal drive unit 17 perform useless actions, resulting in a lot of time spent until the measurement is completed.

[0065] Therefore, in order to minimize the useless actions during the movement between the measurement points, the measurement order needs to be considered. The control unit 20 uses various measurement orders and calculates the predicted time including the movement time between the measurement points based on the set values of the radius (R) and the angle (θ) of the measurement points included in the process, and automatically selects the fastest measurement order. For example, three rules are prepared for the measurement order and the measurement points are re-ordered accordingly.

[0066] Examples of the rules (measurement modes) of the measurement order are as follows.

[0067] [Measurement Mode A]

[0068] Set the order registered with the control information input from the operation unit 18 without re-ordering (process setting order),

[0069] [Measurement Mode B]

[0070] The order that minimizes the movement of the arm of the probe horizontal drive unit 17 where the four-probe head 14 is installed (minimum arm movement amount order),

[0071] [Measurement Mode C]

[0072] The order that minimizes the rotation of the measurement stage 11 on which the semiconductor wafer 12 is placed (minimum table rotation amount order).

[0073] In addition, the measurement order is not limited to the above three rules, as long as there are two or more of them. For example, the control unit 20 calculates the predicted time required for the measurement when measuring according to the measurement mode A, re-orders the setting order of each measurement point set by the control information according to the measurement mode B or the measurement mode C, and calculates the predicted time when the measurement is performed according to the re-ordered setting order. The control unit 20 selects the setting order with the fastest (shortest) predicted time from the respectively calculated predicted times and performs the measurement according to the selected setting order.

[0074] First, use Figure 6 to illustrate measurement mode A. In the case of the process setting as shown in Figure 6 (a), the normal measurement sequence following the process setting sequence is as shown in Figure 6 (b). Figure 6 The nine small black circles shown in (b) of are measurement points, and the circled numbers represent the numbers of the measurement points. Here, measurement points 1 to 9 correspond to the circled numbers 1 to 9. In addition, the setting sequence is in ascending order of the numbers of the measurement points. Measurement point 1 is located at the rotation center O of the measurement stage 11, i.e., the center of the semiconductor wafer 12, and the setting sequence is 1. When the process is set in the setting sequence shown in Figure 6 (a), the measurement sequence is set to the ascending order of the numbers of the setting sequence, i.e., Figure 6 the ascending order of the circled numbers shown in (b) of .

[0075] Next, use Figure 7 and Figure 8 to illustrate measurement mode B. As shown in Figure 7 , the method for selecting the measurement sequence of mode B is as follows.

[0076] (Step S1)

[0077] The control unit 20 reorders the setting sequence registered in the process in ascending order of radius, angle, and setting sequence. Here, the priority of reordering is radius > angle > setting sequence.

[0078] (Step S2)

[0079] The control unit 20 determines whether there is one measurement point on the same circumference at the measurement point with the smallest radius. If there is one measurement point on the same circumference ("yes" case), it ends and proceeds to the determination of the measurement point with the second smallest radius (step S2).

[0080] (Step S3)

[0081] If there are multiple measurement points on the same circumference ("no" case), the control unit 20 calculates the point closest to the previous measurement point and selects it as the next measurement point, and determines the path counterclockwise.

[0082] (Step S4)

[0083] The control unit 20 determines whether there are two closest points (two points at the same distance).

[0084] (Step S5)

[0085] In the case of having two closest points ("yes" case), the control unit 20 selects the initial measurement point counterclockwise from the previous measurement point, and then reorders counterclockwise from here. Proceed to the determination of the measurement point with the smallest radius among the remaining measurement points (step S2).

[0086] (Step S6)

[0087] In the case of having only one closest point ("no" case), the control unit 20 reorders counterclockwise from the closest point. Proceed to the determination of the measurement point with the smallest radius among the remaining measurement points (step S2).

[0088] The control unit 20 determines the measurement order by repeating the steps after step S2 in ascending order of the radius.

[0089] The method for selecting the measurement order using measurement mode B is relative to the Figure 6 process determined as in Figure 8 (a) as shown. Hereinafter, a detailed description will be given.

[0090] Since only the first set measurement point 1 is on the same circumference with the smallest radius (R = 0), the measurement order of measurement point 1 (set order 1) is "1", and measurement point 1 is the measurement start position S.

[0091] Since only the second set measurement point 2 is on the same circumference with the second smallest radius (R = 60), the measurement order of measurement point 2 (set order 2) is "2".

[0092] The third, fourth, and fifth set measurement points 3, 4, and 5 are on the same circumference with the third smallest radius (R = 80). Measurement points 3 and 4 are at the same distance from the previous measurement point 2. Therefore, in step S5, first, the initial measurement point 4 is selected counterclockwise from measurement point 2, and then measurement points 5 and 3 are selected counterclockwise. Thus, the measurement order of measurement point 4 (set order 4) is "3", the measurement order of measurement point 5 (set order 5) is "4", and the measurement order of measurement point 3 (set order 3) is "5".

[0093] The sixth and seventh set measurement points 6 and 7 are on the same circumference with the fourth smallest radius (R = 100). Measurement point 7 is at the closest distance from the previous measurement point 3. Therefore, in step S3, measurement point 7 is selected first, and then measurement point 6 is selected counterclockwise. Thus, the measurement order of measurement point 7 (set order 7) is "6", and the measurement order of measurement point 6 (set order 6) is "7".

[0094] The eighth and ninth set measurement points 8 and 9 are located on the same circumference with the fifth smallest radius (R = 140). Since the measurement points 8 and 9 are at the same distance from the previous measurement point 6, in step S5, first, the initial measurement point 8 is selected counterclockwise from the measurement point 6, and then the measurement point 9 is selected counterclockwise. Therefore, the measurement order of the measurement point 8 (setting order 8) is "8", the measurement order of the measurement point 9 (setting order 9) is "9", and the measurement point 9 is the measurement end position E.

[0095] Next, use Figures 9 - 10 to illustrate the measurement mode C. As Figure 9 shown, the method for selecting the measurement order of mode C is as follows.

[0096] (Step S11)

[0097] The control unit 20 re-orders the setting orders registered in the process in ascending order of angle > radius > setting order. Here, the re-ordering priority is angle > radius > setting order.

[0098] (Step S12)

[0099] The control unit 20 determines whether there is one measurement point at the same angle among the measurement points with the minimum angle. In the case where there is one measurement point at the same angle ("yes" case), it ends and proceeds to the determination of the measurement point with the minimum angle among the remaining measurement points (step S12).

[0100] (Step S13)

[0101] In the case where there are multiple measurement points at the same angle ("no" case), the control unit 20 calculates the moving distance of the arm of the probe horizontal drive unit 17 from the previous measurement point.

[0102] (Step S14)

[0103] The control unit 20 determines the shorter path of the moving distance (which one is shorter between the path moving from a point with a smaller radius to a point with a larger radius and the path moving from a point with a larger radius to a point with a smaller radius).

[0104] (Step S15)

[0105] When the moving distance becomes shorter when moving from a point with a smaller radius to a point with a larger radius, the control unit 20 re-orders in ascending order of radius. In the case where the moving distance of any path is equal (the case where there are measurement points with a smaller radius and measurement points with a larger radius compared to the previous measurement point), it also re-orders in ascending order of radius. Proceed to the determination of the measurement point with the minimum angle among the remaining measurement points (step S12).

[0106] (Step S16)

[0107] When the moving distance becomes shorter when moving from a point with a larger radius to a point with a smaller radius, the control unit 20 reorders in descending order of the radius. It proceeds to the determination of the measurement point with the smallest radius among the remaining measurement points (step S12).

[0108] The control unit 20 determines the measurement order by repeating the steps after step S12 in ascending order of the angle.

[0109] The method for selecting the measurement order using pattern C is as follows with respect to the measurement order determined for the process set as Figure 6 in (a) as shown. Hereinafter, a detailed description will be given. Figure 10 shown. Hereinafter, a detailed description will be given.

[0110] Since only the first set measurement point 1 is on the same radius at the minimum angle (θ = 0), the measurement order of measurement point 1 (set order 1) is "1", and measurement point 1 is the measurement start position S.

[0111] Since only the eighth set measurement point 8 is on the same radius at the minimum angle (θ = 10) among the remaining measurement points, the measurement order of measurement point 8 (set order 8) is "2".

[0112] The third and seventh set measurement points 3 and 7 are on the same radius at the minimum angle (θ = 30) among the remaining measurement points. Since the moving distance between measurement point 7 and the previous measurement point 8 is the shortest, in step S15, the measurement point 7 with a larger radius is selected first, and then measurement point 3 is selected. Therefore, the measurement order of measurement point 7 (set order 7) is "3", and the measurement order of measurement point 3 (set order 3) is "4".

[0113] Since only the second set measurement point 2 is on the same radius at the minimum angle (θ = 60) among the remaining measurement points, the measurement order of measurement point 2 (set order 2) is "5".

[0114] Since only the fourth set measurement point 4 is on the same radius at the minimum angle (θ = 90) among the remaining measurement points, the measurement order of measurement point 4 (set order 4) is "6".

[0115] Since only the fifth set measurement point 5 is on the same radius at the minimum angle (θ = 180) among the remaining measurement points, the measurement order of measurement point 5 (set order 5) is "7".

[0116] Since only the ninth set measurement point 9 is on the same radius at the minimum angle (θ = 290) among the remaining measurement points, the measurement order of measurement point 9 (set order 9) is "8".

[0117] Since only the sixth set measurement point 6 is on the same radius as the smallest angle (θ = 330) among the remaining measurement points, the measurement order of measurement point 6 (set order 6) is "9", and measurement point 6 is the measurement end position E.

[0118] (Measurement time investigation)

[0119] The measurement time for the movement amounts of the arm of the probe horizontal drive unit 17 equipped with the 4-probe head 14 and the measurement table 11 was investigated. Here, the movement amount refers to the amount (mm or degrees) when the arm of the probe horizontal drive unit 17 and the measurement table 11 move from the current measurement point to the next measurement point respectively, and the measurement time refers to the time (seconds (s)) until the arm of the probe horizontal drive unit 17 and the measurement table 11 move to the next measurement point and the measurement ends. Figure 11 The dashed arrow of the straight line is the movement amount of the arm of the probe horizontal drive unit 17 (arm movement amount: x r ), and the solid arrow of the arc shape is the movement amount of the measurement table 11 (table movement amount (table rotation amount): x θ ).

[0120] Figure 12 (a) of shows a graph of obtaining measurement values and an approximate curve regarding the relationship between the arm movement amount and the measurement time, Figure 12 (b) of shows a graph of obtaining measurement values and an approximate curve regarding the relationship between the table movement amount and the measurement time.

[0121] According to Figure 12 (a), the following formula (1) is calculated, and according to Figure 12 (b), the following formula (2) is calculated. When the arm movement amount as the movement amount in the radial direction is set as x r , the table movement amount as the movement amount in the angular direction is set as x θ , the time accompanying the movement in the radial direction is set as y r , and the time accompanying the movement in the angular direction is set as y θ ,

[0122] y r = -4×(10 -6 )x r 2 + 0.006x r + 1.9564 (0 ≤ x r < 150) (1)

[0123] y θ = -2×(10 -5 )x θ 2 + 0.0081x θ+2.0083(0≤x θ <180) (2).

[0124] At x r =0, x θ =0 (not moved respectively), y r =1.9564, y θ =2.0083. The constant parts of equations (1) and (2) can be judged as the time for probing ~ measuring ~ retracting.

[0125] y r =1.9564 (s), y θ =2.0083 (s) are fixed for each movement amount, so they are omitted. The following equations (3) and (4) are used to calculate the predicted measurement time. That is, when the arm movement time as the movement time in the radial direction is set as y r , and the stage movement time as the movement time in the angular direction is set as y θ ,

[0126] y r = -4×(10 -6 )x r 2 +0.006x r (0≤x r <150) (3)

[0127] y θ = -2×(10 -5 )x θ 2 +0.0081x θ (0≤x θ <180) (4).

[0128] Next, taking the process information of (a) in Figure 13 as an example, the calculation examples of the predetermined measurement times for measurement modes A, B, and C are described.

[0129] In the case of measurement mode A, the setting order is the measurement order. When the movement amounts (radius, angle) of measurement orders 1→2, 2→3, 3→4, 4→5 are set as (r1, θ1), (r2, θ2), (r3, θ3), (r4, θ4) respectively, and the predicted measurement times (radius, angle) are set as (y r1 , y θ1 ), (y r2 , y θ2 ), (y r3 , y θ3 ), (y r4 , y θ4 ) respectively,

[0130] (r1, θ1) = (90, 180)

[0131] (r2, θ2) = (40, 135)

[0132] (r3, θ3) = (40, 180)

[0133] (r4, θ4) = (90, 180).

[0134] When substituting this information into the aforementioned formulas (3) and (4) to calculate the predicted measurement time,

[0135] y r1 = -4×10 -6 ×90 2 + 0.006×90 = 0.5076

[0136] y θ1 = -2×10 -5 ×180 2 + 0.0081×180 = 0.81

[0137] y r2 = -4×10 -6 ×40 2 + 0.006×40 = 0.2336

[0138] y θ2 = -2×10 -5 ×135 2 + 0.0081×135 = 0.729

[0139] y r3 = -4×10 -6 ×40 2 + 0.006×40 = 0.2336

[0140] y θ3 = -2×10 -5 ×180 2 + 0.0081×180 = 0.81

[0141] y r4 = -4×10 -6 ×90 2 + 0.006×90 = 0.5076

[0142] y θ4 = -2×10 -5 ×180 2 + 0.0081×180 = 0.81.

[0143] The arm of the probe horizontal drive unit 17 moves simultaneously with the measurement table 11 until the next measurement point. Therefore, yr and y θ The maximum value of is regarded as the measurement time. Therefore, when the overall predicted measurement time is set to T totalA at this time,

[0144] T totalA = y θ1 + y θ2 + y θ3 + y θ4 = 3.159 (s).

[0145] In the case of measurement mode B, the measurement order is as shown in Figure 13 (b) of. The amount of movement is:

[0146] (r1, θ1) = (0, 45)

[0147] (r2, θ2) = (90, 135)

[0148] (r3, θ3) = (0, 45)

[0149] (r4, θ4) = (40, 180).

[0150] When substituting this information into the aforementioned equations (3) and (4) to calculate the predicted measurement time,

[0151] y r1 = -4×10 -6 ×0 2 + 0.006×0 = 0

[0152] y θ1 = -2×10 -5 ×45 2 + 0.0081×45 = 0.324

[0153] y r2 = -4×10 -6 ×90 2 + 0.006×90 = 0.5076

[0154] y θ2 = -2×10 -5 ×135 2 + 0.0081×135 = 0.729

[0155] y r3 = -4×10 -6 ×0 2 + 0.006×0 = 0

[0156] y θ3 = -2×10 -5 ×45 2 + 0.0081×45 = 0.324

[0157] y r4 = -4×10 -6 ×40 2 +0.006×40 = 0.2336

[0158] y θ4 = -2×10 -5 ×180 2 +0.0081×180 = 0.81。

[0159] When the overall predicted measurement time is set to T totalB at that time,

[0160] T totalB = y θ1 + y θ2 + y θ3 + y θ4 = 2.187(s).

[0161] In the case of measurement mode C, the measurement order is as shown in Figure 13 (c) of. The amount of movement is:

[0162] (r1, θ1) = (0, 45)

[0163] (r2, θ2) = (130, 0)

[0164] (r3, θ3) = (40, 135)

[0165] (r4, θ4) = (0, 45).

[0166] When substituting this information into the aforementioned equations (3) and (4) to calculate the predicted measurement time,

[0167] y r1 = -4×10 -6 ×0 2 +0.006×0 = 0

[0168] y θ1 = -2×10 -5 ×45 2 +0.0081×45 = 0.324

[0169] y r2 = -4×10 -6 ×130 2 +0.006×130 = 0.77948

[0170] y θ2 = -2×10 -5 ×0 2 +0.0081×0 = 0

[0171] y r3 = -4×10 -6 ×40 2 +0.006×40 = 0.2336

[0172] y θ3 = -2×10 -5 ×135 2 +0.0081×135 = 0.729

[0173] y r4 = -4×10 -6 ×0 2 +0.006×0 = 0

[0174] y θ4 = -2×10 -5 ×45 2 +0.0081×45 = 0.324。

[0175] When the overall predicted measurement time is set to T totalC ,

[0176] T totalC = y θ1 + y r2 + y θ3 + y θ4 = 2.15648(s).

[0177] According to T totalA , T totalB , T totalC it can be known that the minimum is T totalC , so the measurement order of mode C is selected. However, in the case of the same predicted measurement time, it is selected with the priority of measurement mode A > measurement mode B > measurement mode C.

[0178] In Figure 13 the process setting example shown in (a), the measurement order of mode C is selected. Next, examples of selecting the measurement order of other measurement modes will be described.

[0179] First, use Figures 14 - 17 to describe the process of selecting the measurement order of mode A.

[0180] In the case of setting the Figure 14 shown process, in measurement mode A, as Figure 15 shown, calculate the movement amount (radius) as the arm movement amount (x r ), the movement amount (angle) as the table movement amount (x θ ), the time (radius) as the arm movement time (y r ), and the time as the table movement time (yθ ) The time (angle). Calculate the larger value between the time (radius) and the time (angle) as the time (s). If the total Figure 15 of the times for setting sequences 2 to 17 shown is calculated, the overall predicted measurement time (T totalA ) is obtained.

[0181] T totalA = 4.626223 (s).

[0182] In the case where the process shown Figure 14 is set, in measurement mode B, the measurement sequence is set as Figure 16 and, as shown Figure 16 , the movement amount (radius) as the arm movement amount (x r ), the movement amount (angle) as the stage movement amount (x θ ), the time (radius) as the arm movement time (y r ), and the time (angle) as the stage movement time (y θ ) are calculated. Calculate the larger value between the time (radius) and the time (angle) as the time (s). If the total Figure 16 of the times for measurement sequences 2 to 17 shown is calculated, the overall predicted measurement time (T totalB ) is obtained.

[0183] T totalB = 5.264549 (s).

[0184] In the case where the process shown Figure 14 is set, in measurement mode C, the measurement sequence is set as Figure 17 and, as shown Figure 17 , the movement amount (radius) as the arm movement amount (x r ), the movement amount (angle) as the stage movement amount (x θ ), the time (radius) as the arm movement time (y r ), and the time (angle) as the stage movement time (y θ ) are calculated. Calculate the larger value between the time (radius) and the time (angle) as the time (s). If the total Figure 17 of the times for measurement sequences 2 to 17 shown is calculated, the overall predicted measurement time (T totalC ) is obtained.

[0185] T totalC = 5.620364 (s).

[0186] Therefore, in the case where the process shown Figure 14 is set, T totalA < T totalB<T totalC , since T totalA is the smallest, the measurement order of measurement mode A is selected.

[0187] Next, use Figures 18 - 21 to illustrate the process of selecting the measurement order of measurement mode B.

[0188] In the case where the Figure 18 shown process is set, in measurement mode A, as Figure 19 shown, calculate the movement amount (radius) as the arm movement amount (x r ), the movement amount (angle) as the table movement amount (x θ ), the time (radius) as the arm movement time (y r ), and the time (angle) as the table movement time (y θ ). Calculate the larger value between the time (radius) and the time (angle) as the time (s). If the times of setting sequences 2 to 17 shown in Figure 15 are summed up, calculate the overall predicted measurement time (T totalA ),

[0189] T totalA = 4.088 (s).

[0190] In the case where the Figure 18 shown process is set, in measurement mode B, the measurement order is set as Figure 20 shown, and as Figure 20 shown, calculate the movement amount (radius) as the arm movement amount (x r ), the movement amount (angle) as the table movement amount (x θ ), the time (radius) as the arm movement time (y r ), and the time (angle) as the table movement time (y θ ). Calculate the larger value between the time (radius) and the time (angle) as the time (s). If the times of measurement sequences 2 to 17 shown in Figure 20 are summed up, calculate the overall predicted measurement time (T totalB ),

[0191] T totalB = 3.7006 (s).

[0192] In the case where the Figure 18 shown process is set, in measurement mode C, the measurement order is set as Figure 21 shown, and as Figure 21 shown, calculate the movement amount (radius) as the arm movement amount (x r ), the movement amount (angle) as the table movement amount (x θ) The amount of movement (angle), the time of the arm movement (y r ) The time (radius), the time of the stage movement (y θ ) The time (angle). Calculate the larger value of the time (radius) and the time (angle) as the time (s). If the sum Figure 21 The times of measurement sequences 2 to 17 shown are calculated, and the overall predicted measurement time (T totalC ) is obtained,

[0193] T totalC = 4.0248 (s).

[0194] Therefore, in the case where the process shown Figure 18 is set, T totalB < T totalC < T totalA Since T totalB is the minimum, the measurement sequence of measurement mode B is selected.

[0195] According to the present embodiment, the operation is to calculate the predicted time when the measurement is performed in the set order of each measurement point set in the process, and in accordance with the change of the measurement mode, the set order of each measurement point set in the process is changed, and the predicted time when the measurement is performed in accordance with the changed set order is calculated, and the set order in which the predicted time is the fastest (becomes the shortest) among the predicted times calculated respectively is selected, and the object to be measured is measured using the selected set order.

[0196] According to the above operation, the measurement time for each semiconductor wafer can be shortened, and the number of wafers that can be measured per unit time can be increased.

[0197] Using the resistivity measuring device for semiconductor wafers of the present embodiment, the resistivity of a silicon wafer, the resistivity of an epitaxial wafer formed on the wafer surface, the sheet resistance of a diffusion layer or an implanted layer in the case of diffusing or implanting impurities from the surface, the sheet resistance of a metal film formed on the surface, etc. are measured, and the measurement results are fed back to the process conditions of each semiconductor manufacturing device, that is, the process conditions are set for the semiconductor manufacturing device based on the measurement results, and the semiconductor manufacturing device processes the semiconductor wafer using the process conditions, thereby improving the quality uniformity of semiconductor devices.

[0198] Description of reference numerals

[0199] 10 Resistivity measuring device

[0200] 11 Measuring stage (stage)

[0201] 12 Semiconductor wafer (object to be measured)

[0202] 14 Four-probe probe (probe)

[0203] 14a probe

[0204] 16 probe up / down drive unit (up / down drive unit)

[0205] 17 probe horizontal drive unit (horizontal drive unit)

[0206] 20 control unit.

Claims

1. A resistivity measurement method, comprising: a first calculation step of calculating a predicted time when measurement is performed in accordance with the set order of each measurement point set in the process of measuring the object to be measured; a second calculation step of changing the set order of each measurement point set in the process according to at least one of a first measurement mode in which the horizontal movement of the probe is minimized when the probe is moved to the measurement position of the object to be measured and a second measurement mode in which the rotational movement of the object to be measured is minimized when the probe is moved to the measurement position of the object to be measured, and calculating a predicted time when measurement is performed in accordance with the changed set order; a step of selecting the set order with the shortest predicted time among the predicted time calculated in the first calculation step and the predicted time calculated according to at least one of the first measurement mode and the second measurement mode in the second calculation step; and a step of measuring the object to be measured in accordance with the selected set order.

2. A method for manufacturing a semiconductor device, wherein it further includes a step of performing a prescribed process on the object to be measured based on the result obtained by measuring the resistivity by the resistivity measurement method described in claim 1.

3. A computer-readable recording medium storing a resistivity measurement program, the resistivity measurement program causing a computer to execute the following steps: a first calculation step of calculating a predicted time when measurement is performed in accordance with the set order of each measurement point set in the process of measuring the object to be measured; a second calculation step of changing the set order of each measurement point set in the process according to at least one of a first measurement mode in which the horizontal movement of the probe is minimized when the probe is moved to the measurement position of the object to be measured and a second measurement mode in which the rotational movement of the object to be measured is minimized when the probe is moved to the measurement position of the object to be measured, and calculating a predicted time when measurement is performed in accordance with the changed set order; a step of selecting the set order with the shortest predicted time among the predicted time calculated in the first calculation step and the predicted time calculated according to at least one of the first measurement mode and the second measurement mode in the second calculation step; a step of measuring the object to be measured in accordance with the selected set order.

4. A resistivity measuring device, comprising: a storage unit that stores at least a process for measuring an object to be measured, and at least one of a first measurement mode in which the horizontal movement of the probe is minimized when the probe is moved to the measurement position of the object to be measured and a second measurement mode in which the rotational movement of the object to be measured is minimized when the probe is moved to the measurement position of the object to be measured; and a control unit that controls in a manner of measuring the object to be measured, wherein the control unit is configured to Calculate the predicted time when measurements are made in the set order of each measurement point set in the process, change the set order of each measurement point set in the process according to at least one of the first measurement mode and the second measurement mode, calculate the predicted time when measurements are made in the changed set order, select the set order with the shortest predicted time among the respectively calculated predicted times, and measure the object to be measured according to the selected set order.

5. The resistivity measuring device according to claim 4, wherein Comprises: A stage for placing the object to be measured; A probe head that makes a plurality of probes contact the object to be measured; A horizontal drive unit that moves the probe head in the horizontal direction; and A vertical drive unit that moves the probe head in the vertical direction.

6. The resistivity measuring device according to claim 5, wherein The first measurement mode is configured to minimize the movement of the arm portion of the horizontal drive unit.

7. The resistivity measuring device according to claim 4, wherein The control unit is configured to reorder the set order registered in the process in ascending order of radius, angle, and set order respectively.

8. The resistivity measuring device according to claim 7, wherein The control unit is configured to prioritize the reordered order in the order of radius, angle, and set order.

9. The resistivity measuring device according to claim 5, wherein The control unit is configured to move the probe head to the measurement position of the object to be measured by using the horizontal drive unit, and make the object to be measured contact the probe head by using the vertical drive unit to measure the object to be measured.

10. The resistivity measuring device according to claim 9, wherein The control unit is configured to determine whether the measurement position is a reference position based on the voltage value between a first probe among the plurality of probes and another second probe among the plurality of probes.

11. The resistivity measuring device according to claim 10, wherein The control unit is configured to set the measurement position as the reference position if the voltage value between the first probe and the second probe is within the threshold.

12. The resistivity measuring device according to claim 10, wherein The control unit is configured to lower the probe head again if the voltage value between the first probe and the second probe is outside the threshold.

13. The resistivity measuring device according to claim 10, wherein The control unit is configured to stop measuring the resistivity if the voltage value between the first probe and the second probe is still outside the threshold even after the probe head is lowered a specified number of times again.

14. The resistivity measuring device according to claim 5, wherein The control unit is configured to raise and lower the vertical drive unit to adjust the press-in amount.

15. The resistivity measuring device according to claim 5, wherein The vertical drive unit at least includes a probe head mounting portion having a specified weight, a motor portion, a vertical drive cam portion, and a cam receiving portion.

16. The resistivity measuring device according to claim 5, wherein It also has a rotation drive unit that rotates the stage on which the object to be measured is placed. The second measurement mode is configured to minimize the rotational movement of the stage on which the object to be measured is placed.

17. The resistivity measuring device according to claim 4, wherein the control unit is configured to reorder the setting sequences registered in the process in such a way that the angle, radius, and setting sequence are incremented respectively.

18. The resistivity measuring device according to claim 17, wherein the control unit is configured to prioritize the reordered sequence in the order of angle, radius, and setting sequence.

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