TWI789619B - Resistivity measuring device, resistivity measuring method, and manufacturing method of semiconductor device - Google Patents

Abstract

[Problem] To provide a technology that "corrects the error of the load generated by each semiconductor wafer film type and each measurement coordinate, and improves the stability and reproducibility of the resistivity measurement value". [Solution] A technology is provided, which is characterized by: a base for placing the object to be measured; a probe for making a plurality of probes contact the object for measurement; a horizontal driving part for moving the probe in the horizontal direction; an up and down driving part , to make the probe move in the vertical direction; the displacement gauge, to measure the pressing amount of the measured object and the probe; and the control part, to move the probe to the measurement position of the measured object through the horizontal driving part, and to move the probe to the measuring position through the vertical driving part. Touch the measured object, measure the amount of the probe being pressed into the measured object by the displacement gauge, and compare the measured value with an arbitrary set value. If the error is outside the threshold value, the error is corrected. control.

Description

Resistivity measuring device, resistivity measuring method, and manufacturing method of semiconductor device

This disclosure relates to a resistivity measuring device, a resistivity measuring method, and a method of manufacturing a semiconductor device.

The resistivity tester of semiconductor wafer is a kind of "resistivity of silicon wafer, resistivity of epitaxial layer formed on the surface of wafer, diffusion layer or injection layer after impurity is diffused from the surface of wafer or injected. The sheet resistance of the wafer, the sheet resistance of the metal film formed on the surface of the wafer, etc." The measurement results are fed back to the process conditions of the semiconductor manufacturing equipment, and it is an important measurement to maintain the uniform quality of the semiconductor element One of the devices. As such a measurement device, there is Patent Document 1 or Patent Document 2.

For example, in Patent Document 1, it is recorded that "the upper and lower driving parts of the probe are equipped with: probe mounting accessories; cam supports; stepping motors; and up and down driving cams, which are always in contact with the front end of the cam supports. In this way, the weight of the probe mounting accessories is supported on the shaft of the stepping motor, and the control unit is configured so that the shaft of the stepping motor and the up and down drive cam perform the rotation at the determined speed and angle according to the desired control information And the up and down position control of the 4-probe probe is performed, and the contact state of the probe is set to the desired contact state in response to the type of semiconductor wafer." Also, in Patent Document 2, it is described that "in order to measure the resistivity of the semiconductor wafer in contact with the upper surface of the semiconductor wafer placed on the measurement platform, a plurality of 4-probe probes are provided, and the corresponding One of the upper and lower driving parts of the plurality of probes selected according to the type operates to select an appropriate 4-probe probe, and the resistivity of the semiconductor wafer is measured with the selected probe. [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Unexamined Patent Publication No. 2005-311009 [Patent Document 2] Japanese Patent Laid-Open No. 2003-163248

[Problems to be Solved by the Invention]

However, due to differences in warpage, warpage, thickness, etc. of semiconductor wafers processed on an actual production line, the desired control information (rotation angle and load) previously stored in memory as in Patent Document 1 In the control program), there is a situation where the error of the load occurs in the measurement of the coordinate position in the plane.

The subject of this disclosure is to provide a technology that "can solve the above problems, correct the error of the load generated by each semiconductor wafer film type and each measurement coordinate, and improve the stability and reproducibility of the resistivity measurement value" . [Means to solve the problem]

According to one aspect of the present invention, a kind of as following technology is provided, and this technology has: Base, to place the object to be measured; Probe, to make multiple probes contact the object to be measured; Horizontal drive part, to move the probe in the horizontal direction; Up and down drive part, to make the probe move in the up and down direction; Displacement gauge, to measure the measured object The pressing amount of the object and the probe; and the control part, the probe is moved to the measurement position of the measured object through the horizontal driving part, the probe is contacted with the measured object through the vertical driving part, and the pressure of the probe is measured by the displacement gauge. The amount of the object to be measured is measured, and the measured value is compared with an arbitrary set value. If the error is outside the threshold value, the control is performed by correcting the error. [Effect of Invention]

According to the present disclosure, the stability and reproducibility of measured resistivity values can be improved.

Hereinafter, referring to FIGS. 1 to 5 , an embodiment of the present disclosure will be described.

As shown in Figure 1, the resistivity measuring device 100 for semiconductor wafers is composed of a measurement platform 1, an operation part 3, a probe probe 4, a measurement part 5, a probe up and down drive part 6, a probe horizontal drive part 7, a platform The rotation drive unit 8, the power supply unit 9, the control unit 10, the display unit 11 and the displacement gauge 12 are constituted.

The measurement platform 1 is a disc-shaped base on which a semiconductor wafer 2 to be measured (object to be measured) is placed. The operation part 3 is to output the information specifying the position of the desired measurement point on the upper surface of the semiconductor wafer 2 to the control part 10. The 4-probe probe 4 is a probe having four probes 4a, 4b, 4c, 4d. The four probes 4 a , 4 b , 4 c , and 4 d come into contact with the upper surface of the semiconductor wafer 2 placed on the measurement platform 1 to measure the resistivity of the semiconductor wafer 2 . In order to measure the resistivity of the semiconductor wafer 2 , the measurement unit 5 is electrically connected to the 4-probe probe 4 .

The probe vertical drive unit 6 is a vertical drive unit that moves the probes 4 a , 4 b , 4 c , 4 d of the four-probe probe 4 independently in the vertical direction and makes them contact the semiconductor wafer 2 . The probe horizontal drive unit 7 is a horizontal drive unit that moves the probe vertical drive unit 6 and the four probe probes 4 along the radial direction of the measurement platform 1 , that is, the radial direction of the semiconductor wafer 2 . The platform rotation drive unit 8 rotates the measurement platform 1 and stops it at a predetermined angle. By the operation of both the probe horizontal drive unit 7 and the stage rotation drive unit 8 , the resistivity at a desired position on the semiconductor wafer 2 can be measured.

The power supply unit 9 supplies electric power for operating each unit of the resistivity measuring device 100 . The control unit 10 is equipped with a CPU and a memory storing the control program executed by the CPU, and drives and controls the platform rotation drive unit 8, the probe horizontal drive unit 7 and the probe up-and-down drive unit 6 according to the control information issued by the command from the operation unit 3. , and it is controlled so that the 4-probe probe 4 comes into contact with the designated measuring point position on the upper surface of the semiconductor wafer 2 . The display unit 11 displays data such as the position of the measuring point or the resistivity of the measured result.

The displacement gauge 12 is "installed near the 4-probe probe 4, and moves up and down on the 4-probe probe 4 by the probe up and down driving part 6 according to the control information (pressing amount) arbitrarily set from the control part 10. During position control, the actual displacement between the upper surface of the semiconductor wafer 2 and the 4-probe probe 4 is measured, and the actual displacement is fed back to the control unit 10, and whether it is consistent with the control information set arbitrarily (press-in Quantity) is consistent, and in the case of errors, it is corrected in such a way as to make it consistent".

In FIG. 1 , the operation is based on the control information input from the operation unit 3. The controlled 4-probe probe 4 is brought into contact with the upper surface of the semiconductor wafer 2 placed on the measurement platform 1, and the semiconductor wafer 2 is measured. Resistance of wafer 2.

Next, the structure of the probe vertical drive unit 6 will be described using FIG. 2 . The probe up and down driving part 6 is composed of a probe mounting fitting 6a, a cam support 6h, a weight 6e, a up and down driving cam 6f and a stepping motor 6g.

The four-probe probe 4 is mounted on the probe installation fitting 6a. The cam support 6h receives the vertical driving force of the probe integrated with the probe mounting fitting 6a. The weight 6e has a mass sufficient to impart a static load in the vertical direction to the probe vertical driving unit 6 . The up and down drive cam 6f is connected to the shaft of the stepping motor 6g, and is always in contact with the front end of the cam support 6h, thereby supporting the probe including the weight of the weight 6e on the shaft of the stepping motor 6g The weight of the mounting accessory 6a. The vertical drive cam 6f is, for example, an eccentric circular cam shape, and can move the cam support 6h up and down by the rotation angle. The stepping motor 6g is axially connected with the cam support 6h and the vertical driving cam 6f, and can rotate and stop at any position of the rotation angle according to the control information commanded from the control unit 10. The cam support 6h is supported by In the probe attachment 6a, the vertical drive cam 6f is supported by a support member independent of the probe attachment 6a.

With the above structure, according to the control information of the load applied to the probe suitable for the type of semiconductor wafer 2 and the vertical movement speed of the probe, the probe vertical driving part 6 is controlled to realize the proper positioning of the 4-probe probe 4 and the semiconductor wafer 2. contact and measure the resistivity of the semiconductor wafer 2.

Here, FIG. 3 shows experimental values showing the relationship between the pressing amount of the probes 4a to 4d, the rotation angle of the vertical drive cam 6f, and the spring stress acting as a load on the semiconductor wafer 2. Also, in the control unit 10, the relationship between the pressing amount, the rotation angle of the up and down driving cam 6f, and the load as shown in the graph of FIG. 3 is stored in the memory device of the control unit 10 as a control program. In this way, the control unit 10 adjusts the rotation angle of the vertical driving cam 6f, and stops the 4-probe probe 4 at any position (pressing amount) shown in FIG. The load to the semiconductor wafer 2 can be adjusted to the surface material of the semiconductor wafer 2, and the contact pressure can be controlled arbitrarily.

Next, a method of measuring resistivity by the resistivity measuring device 100 of a semiconductor wafer will be described using FIG. 4 .

(step S1) The control unit 10 moves the probe up and down driving unit 6 and the four probe probes 4 in the radial direction through the probe horizontal driving unit 7, and, through the platform rotation driving unit 8, places the semiconductor wafer 2 and makes the measurement platform 1 is rotated, and the 4-probe probe 4 is moved to a desired position on the semiconductor wafer 2.

(step S2) The control unit 10 lowers the 4-probe probe 4 with the probe vertical driving unit 6 at an arbitrary setting of the pushing amount, and makes the probes 4 a to 4 d contact the semiconductor wafer 2 .

(step S3) The determination of the contact reference position (the position where the pressing amount is 0.00 mm) is as shown in FIG. And determine whether its voltage is within 0mV±threshold value.

(step S4) The control unit 10 sets the time point when the voltage between the probe 4b and the probe 4c becomes 0mV in step S3 as the contact reference position (the position where the pressing amount is 0.00mm).

(step S5) The control unit 10 raises the 4-probe probe 4 through the probe up and down drive unit 6 .

(step S6) The control unit 10 lowers the 4-probe probe 4 to contact the semiconductor wafer 2 with an arbitrary setting of the pushing amount by the probe vertical driving unit 6 .

(step S7) The control unit 10 judges whether the error between any set value of the pushing amount and the actual pushing amount (displacement amount) caused by the displacement gauge 12 is within the threshold value.

(step S8) If the error between any set value of the pushing amount and the actual pushing amount (displacement) caused by the displacement gauge 12 is not within the threshold value, the control unit 10 corrects the error and moves to step S5 Re-run. In addition, the control unit 10 stops the resistivity measurement when the voltage value between the probe 4b and the probe 4c is outside the threshold even if the lowering of the 4-probe probe 4 is repeated a predetermined number of times. In this case, the control unit 10 displays on the display unit 11 an alarm indicating that the resistivity measurement is stopped.

(step S9) When the aforementioned error is within the threshold value, the control unit 10 measures the resistivity.

According to the present embodiment, its operation is "according to the control information (pressing amount) arbitrarily set from the control part 10, when the 4-probe probe 4 is controlled up and down by the probe up and down drive part 6, the displacement The meter 12 measures the actual displacement between the upper surface of the semiconductor wafer 2 and the 4-probe probe 4, and feeds back the actual displacement to the control unit 10, and determines whether it is consistent with the control information (pressing amount) set arbitrarily , which is automatically corrected in such a way as to make it consistent in the presence of errors".

With the above configuration, the probe vertical drive unit 6 can be controlled according to the control information of the load applied to the probe suitable for the type of semiconductor wafer 2 and the vertical movement speed of the probe, and the connection between the 4-probe probe 4 and the semiconductor wafer 2 can be realized. The resistivity of the semiconductor wafer 2 is properly contacted and measured.

The semiconductor wafer resistivity measuring device of this embodiment is used to measure the "resistivity of the silicon wafer, the resistivity of the epitaxial layer formed on the surface of the wafer, and the diffusion layer after impurity is diffused from the surface of the wafer or implanted." Or the sheet resistance of the implanted layer, the sheet resistance of the metal film formed on the wafer surface, etc.", and the measurement results are fed back to the process conditions of each semiconductor manufacturing device, that is, based on the measurement results, the process is set in the semiconductor manufacturing device Conditions, and the semiconductor manufacturing device processes the semiconductor wafer through its process conditions, thereby improving the uniformity of the quality of the semiconductor device.

<Best form of this disclosure> Hereinafter, the preferred aspects of this disclosure are appended.

(Note 1) According to one aspect of the present invention, a resistivity measuring device is provided, which is characterized in that it has: Base, carrying the object to be measured; a probe, making a plurality of probes contact the aforementioned object to be measured; a horizontal driving part to move the aforementioned probe along the horizontal direction; The upper and lower driving parts make the aforementioned probe move in the up and down direction; a displacement gauge for measuring the pressing amount of the aforementioned object to be measured and the aforementioned probe; and The control unit moves the probe to the measurement position of the object to be measured by the horizontal drive unit, makes the probe contact the object to be measured by the vertical drive unit, and measures the pressure of the probe by the displacement gauge. The amount of the object to be measured is compared with the actual measured value and an arbitrary set value, and when the error is outside the threshold value, control is performed to correct the error.

(Note 2) According to other aspects of the present invention, a method for manufacturing a semiconductor device is provided, which is characterized in that it has: With a resistivity measuring device, "select from the resistivity of the silicon wafer, the resistivity of the epitaxial layer formed on the wafer surface, the diffusion layer or the implanted layer when the impurity is diffused from the wafer surface or implanted. resistance or the sheet resistance of the metal film formed on the surface of the wafer to measure any one of the group." The resistivity measuring device is equipped with: a base for placing the object to be measured; a probe for making multiple A probe is in contact with the object to be measured; a horizontal drive unit moves the probe in the horizontal direction; a vertical drive unit moves the probe in the up and down direction; a displacement gauge measures the amount of pressing between the object to be measured and the probe and a control unit, which moves the probe to the measurement position of the measured object by the horizontal drive unit, makes the probe contact the measured object by the vertical drive unit, and measures the probe by the displacement gauge. Press the amount of the aforementioned object to be measured, and compare the measured value with an arbitrary set value. If the error is outside the threshold, control is performed by correcting the error; The process of setting the process conditions of semiconductor manufacturing equipment based on the measured resistivity or sheet resistance; and The process of processing semiconductor wafers based on the set process conditions.

(Note 3) In the resistivity measuring device of Supplementary Note 1, preferably, The control unit is configured to determine whether the measurement position is a reference position in response to a voltage value between the first probe of one of the plurality of probes and the second probe of the other of the plurality of probes. .

(Note 4) In the resistivity measuring device of Supplementary Note 3, preferably, The control unit is configured to set the measurement position as a reference position as long as the voltage value between the first probe and the second probe is within a threshold value.

(Note 5) In the resistivity measuring device of Supplementary Note 3, preferably, The control unit is configured to re-execute the lowering of the probe as long as the voltage value between the first probe and the second probe is outside a threshold value.

(Note 6) In the resistivity measuring device of Supplementary Note 4, preferably, The control unit is configured to stop the resistivity measurement when the voltage value between the probes is outside a threshold value even if the lowering of the probe is repeated a predetermined number of times.

(Note 7) In the resistivity measuring device of Supplementary Note 1, preferably, The control unit is configured to move the vertical driving unit up and down to adjust the pushing amount.

(Note 8) In the resistivity measuring device of Supplementary Note 7, preferably, The above-mentioned up-and-down driving part includes at least: a probe mounting part having a predetermined weight; a motor part (stepping motor); a vertical driving cam part; and a cam supporting part.

(Note 9) In the resistivity measuring device of Supplementary Note 8, preferably, The control unit is configured to adjust the rotation angle of the vertical driving cam unit.

(Additional Note 10) In the resistivity measuring device of Supplementary Note 1, preferably, I have a display part more, The control unit is configured to display, on the display unit, an alarm indicating that the resistivity measurement is stopped.

(Additional Note 11) A method of manufacturing a semiconductor device, characterized by: the work of preparing the object to be measured; and The process of measuring the resistivity or sheet resistance of the aforementioned object to be measured by using the resistivity measuring device as in Supplementary Note 1.

(Additional Note 12) The method of manufacturing a semiconductor device as in Supplement 11, wherein, The aforementioned object to be measured is a wafer including at least a silicon wafer, In the process of measuring the resistivity or sheet resistance of the aforementioned object to be measured, it is "selected from the resistivity of the aforementioned silicon wafer, the resistivity of the epitaxial layer formed on the wafer surface, the diffusion of impurities from the wafer surface or The sheet resistance of the diffusion layer or the implanted layer after implantation, or the sheet resistance of the metal film formed on the surface of the wafer is measured."

(Additional Note 13) For example, the method of manufacturing a semiconductor device in Supplement 12, further comprising: The process of setting the process conditions of semiconductor manufacturing equipment based on the measured resistivity or sheet resistance; and The process of processing semiconductor wafers based on the set process conditions.

(Additional Note 14) A method for measuring electrical resistivity is characterized in that it has: the preparation of the substrate works; and The process of measuring the resistivity of the object to be measured on the surface of the substrate by using the resistivity measuring device as in Supplementary Note 1.

1: Measuring platform (base) 2: Semiconductor wafer (measured object) 4:4 probe probe (probe) 4a~4d: probe 6: Probe up and down driving part (up and down driving part) 7: Probe horizontal driving part (horizontal driving part) 10: Control Department 12: Displacement gauge 100: resistivity tester

[ Fig. 1] Fig. 1 is a block diagram showing the configuration of a semiconductor wafer resistivity measuring device according to an embodiment of the present disclosure. [ Fig. 2 ] An external view showing the configuration of a probe vertical drive unit, a 4-probe probe, a semiconductor wafer, a measurement stage, and a displacement gauge according to an embodiment of the present disclosure. [ Fig. 3 ] A graph showing experimental values of the relationship between the pressing amount of the probe, the rotation angle of the vertical drive cam, and the cam stress. [ Fig. 4 ] A flow chart showing a measurement operation in an embodiment of the present disclosure. [FIG. 5] A diagram showing the relationship between a probe probe, a constant current source, a voltmeter, and a semiconductor wafer in a 4-probe measurement method.

1: Determination platform

2: Semiconductor wafer

3: Operation department

4:4 Probe Probe

4a: Probe

4b: Probe

4c: Probe

4d: Probe

5: Measurement department

6: Probe up and down drive unit

7: Probe horizontal drive unit

8: Platform rotation drive unit

9: Power supply department

10: Control Department

11: Display part

12: Displacement gauge

100: resistivity tester

Claims (9)

A resistivity measuring device is characterized by the following: a base for placing an object to be measured; a probe for making a plurality of probes contact the object to be measured; a horizontal driving part for moving the aforementioned probe in a horizontal direction; an up and down driving part for The probe is moved in the vertical direction; the displacement gauge measures the pressing amount of the object to be measured and the probe; and the control unit moves the probe to the measurement position of the object to be measured by the horizontal drive unit. The probe is brought into contact with the object to be measured by the vertical drive unit, the amount of the probe being pressed into the object to be measured is actually measured by the displacement gauge, and the measured value is compared with an arbitrary set value, and if the error is beyond the threshold In this case, the control is performed by correcting the error, and the control unit is configured to respond to the difference between the first probe of one of the plurality of probes and the second probe of the other of the plurality of probes. The voltage value is used to determine whether or not the measurement position is a reference position. The resistivity measuring device according to claim 1, wherein the control unit is configured to set the measurement position as a reference position as long as the voltage value between the first probe and the second probe is within a threshold value . The resistivity measuring device according to claim 1, wherein the control unit is configured to re-execute the lowering of the probe as long as the voltage value between the first probe and the second probe is outside a threshold value. Such as the resistivity measuring device of claim 2, wherein, The control unit is configured to stop the resistivity measurement when the voltage value between the probes is outside a threshold value even if the lowering of the probe is repeated a predetermined number of times. The resistivity measuring device according to claim 1, wherein the control unit is configured to move the vertical drive unit up and down to adjust the pushing amount. The resistivity measuring device according to claim 1, wherein the above-mentioned vertical driving part at least includes: a probe mounting part having a predetermined weight; a motor part; a vertical driving cam part; and a cam supporting part. The resistivity measuring device according to claim 6, wherein the control unit is configured to adjust the rotation angle of the vertical driving cam unit. A method for measuring electrical resistivity, which is characterized by: a process of preparing an object to be measured; and a process of measuring the resistivity or sheet resistance of the object to be measured by a resistivity measuring device, the resistivity measuring device is equipped with : The base is used to place the object to be measured; the probe is used to make a plurality of probes contact the object to be measured; the horizontal drive unit is used to move the probe in the horizontal direction; the vertical drive unit is used to move the probe in the vertical direction; the displacement gauge , to measure the pressing amount of the object to be measured and the probe; and a control unit to move the probe to the measurement position of the object to be measured by the horizontal drive unit, and to make the probe contact the probe by the vertical drive unit. The object to be measured is to measure the amount of the probe being pressed into the object to be measured by the aforementioned displacement gauge, and compare the measured value with the Any setting value is controlled by correcting the error when the error is outside the threshold value. The control unit is configured to respond to the first probe among the plurality of probes and the plurality of probes. The voltage value between the other of the second probes determines whether or not the measurement position is a reference position. A method of manufacturing a semiconductor device, characterized by comprising: a step of preparing an object to be measured; and a step of measuring the resistivity of the object to be measured by using a resistivity measuring device, the resistivity measuring device having: a base , to place the object to be measured; probe, to make a plurality of probes contact the above-mentioned object to be measured; the horizontal drive part, to make the above-mentioned probe move in the horizontal direction; the up and down drive part, to make the above-mentioned probe move in the up and down direction; The amount of pressing between the object to be measured and the probe; and a control unit for moving the probe to the measurement position of the object to be measured by the horizontal driving unit, and making the probe contact the measured object by the vertical driving unit Object, the amount of the probe being pressed into the object to be measured is actually measured by the aforementioned displacement gauge, the actual measured value is compared with an arbitrary set value, and if the error is outside the threshold value, the error is corrected for control. The unit is configured to determine whether the measurement position is a reference position in response to a voltage value between a first probe of one of the plurality of probes and a second probe of the other of the plurality of probes.

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