JP2000068338A - Wafer prober and wafer positioning method - Google Patents

Abstract

(57) [Summary] [Problem] Due to the shape of a probe tip and the degree of gloss thereof, it is difficult to recognize an accurate position by optical measurement. Therefore, correction work by an operator using an initial wafer is required. It was difficult to automate the precise alignment. A probe connected to a tester for measuring electrical characteristics of a semiconductor device, the probe being in contact with an electrode of the semiconductor device formed on the wafer, and a wafer;
Is mounted on the wafer prober 11 and a stage device 43 for moving the wafer 31 up and down.
Measuring unit 51 for measuring the capacitance between the electrodes by contacting the
And whether or not the electrode 32 and the probe 21 are in contact with each other is determined based on whether or not the capacitance can be measured by the capacitance measuring unit 51.
And a control unit 61 for giving instructions to the user.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer prober and a method for positioning a wafer, and more particularly, to measuring a capacitance between measurement electrodes of a semiconductor device to determine an accurate position of the wafer with respect to a probe to obtain electrical characteristics. The present invention relates to a wafer positioning method for determining a distance between a probe and a wafer by measuring a capacitance between a wafer prober for performing a test and a measurement electrode of a semiconductor device to determine a position of the wafer with respect to the probe.

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. In FIG. 5, the height of the stage with respect to the probe is adjusted as follows.

[0005] As shown in FIG. 5A, light L emitted from a light source 121 is applied to a probe 112 A, for example, a probe 112 fixed to a probe card (not shown). Then, the reflected light R reflected by the probe 112A is captured by the CCD camera 122 and recognized as image data.

[0004] The control unit 131 uses the image data to position the tip of the probe 112 and the wafer 101.
Then, a stage drive command is sent to the stage drive unit 141 based on the distance data to drive the stage drive unit 141, and the stage 142 is raised. As a result, as shown in FIG.
12 and the wafer 101 are automatically approached.

The above-mentioned conventional technique is a technique for automating an operation of aligning a probe 112 and a measurement pad 102 which is an electrode formed on a wafer 101.
The automation has an advantage that the processing capability can be improved, and positioning can be performed even in a pad layout that is not visible.

[0006]

However, in the above-mentioned prior art, it was difficult to recognize an accurate position depending on the shape of the tip of the probe and the degree of gloss thereof.
Further, even if the position of the tip of the probe can be recognized, the accuracy is insufficient, and it is necessary to perform a correction operation by an operator on the initial wafer. As a result, it has been difficult to completely automate the alignment.

[0007]

SUMMARY OF THE INVENTION The present invention is directed to a wafer prober and a wafer positioning method for solving the above-mentioned problems.

A wafer prober according to the present invention is connected to a tester for measuring electrical characteristics of a semiconductor device. The probe is in contact with an electrode of the semiconductor device formed on the wafer, and the wafer prober has the wafer mounted thereon. A stage device capable of moving the wafer up and down, and a capacitance measuring unit that is electrically connected to the probe and that contacts the probe with an electrode to measure the capacitance between the electrodes via the probe. A controller for determining whether or not the electrode and the probe are in contact with each other based on whether or not the capacitance can be measured by the capacitance measuring unit, and instructing the stage device to raise or lower the wafer based on whether or not the contact is possible.

Since the above-mentioned wafer prober has a probe and a capacitance measuring section for connecting the probe, the capacitance between the electrodes is reduced by bringing the probe connected to the capacitance measuring section into contact with the electrode of the semiconductor device. It becomes possible to measure. In addition, since the control unit instructs the stage device to elevate and lower the wafer by determining whether the electrode and the probe can be in contact with each other based on whether the capacitance measurement unit can measure the capacitance, the electrode and the probe are in contact with each other. Otherwise, it is impossible to measure the capacitance between the electrodes, so the distance between the electrode and the probe is reduced stepwise, for example, and each time it is determined whether the capacitance between the electrodes can be measured. The optimal contact position (position in the height direction) between the probe and the probe is determined. On the other hand, when the electrode is in contact with the probe, the capacitance between the electrodes can be measured. In each case, by determining whether or not the capacitance between the electrodes can be measured, an optimum contact position (a position in the height direction) between the electrode and the probe is determined. Further, since the amount of elevation of the wafer can be instructed to the stage device depending on whether or not the capacitance can be measured, the distance between the electrode and the probe can be increased or decreased.

[0010] In the wafer positioning method of the present invention, a probe electrically connected to a tester is brought into contact with an electrode of a semiconductor device formed on the wafer to test an electrical characteristic of the semiconductor device. This is a wafer positioning method for determining a height position.

That is, in the first capacitance measuring step, the capacitance between the electrodes of the semiconductor device is measured via the probe. Then, in a first measurement determining step, it is determined whether or not the capacitance between the electrodes can be measured in the first capacitance measuring step. As a result of the first measurement judging step, if the capacitance can be measured, the wafer is lowered by a predetermined amount in the wafer lowering step, and the capacitance between the electrodes of the semiconductor device is probed in the second capacitance measuring step. Measure through. Next, a second measurement determining step of determining whether or not the capacitance between the electrodes can be measured in the second capacitance measuring step is performed.

As a result of the second measurement judging step, if the capacity can be measured, it is instructed to lower the wafer by a predetermined amount in the wafer lowering / measuring instructing step and to perform the second capacity measuring step and thereafter again. I do. On the other hand, if the capacity measurement is impossible as a result of the second measurement judging step, the wafer is raised by a predetermined amount in the wafer raising / ending instruction step to instruct the end of the alignment.

On the other hand, as a result of the first measurement judging step, if the capacitance cannot be measured, the wafer is raised by a predetermined amount in the wafer raising step. Thereafter, it is determined whether or not the wafer raising amount is equal to or less than a specified amount in a wafer raising amount determining step. As a result of the step of determining the amount of rise of the wafer, if the amount of rise of the wafer is equal to or smaller than the specified amount, the capacitance between the electrodes of the semiconductor device is measured via a probe in a third capacitance measurement step. Thereafter, a third measurement determination step is performed to determine whether or not the capacitance between the electrodes can be measured in the third capacitance measurement step.

As a result of the third measurement judging step, if the capacitance can be measured, an instruction to end the wafer alignment is issued. On the other hand, as a result of the third measurement determining step, if the capacity measurement is impossible, an instruction to raise the wafer by a predetermined amount and proceed to the wafer raising amount determining step is performed in the wafer raising / measuring instruction step. If the result of the wafer rising amount determination step indicates that the wafer rising amount exceeds the specified amount, a stop step of stopping the calculation as an error is performed.

In the above-described wafer positioning method, the first,
In the second and third measurement determination steps, it is determined whether or not the probe is in contact with the electrode by determining whether or not the capacitance can be measured. That is, if the capacitance can be measured, the probe is in contact with the electrode. If the capacitance cannot be measured, the probe is not in contact with the electrode. Thus, it is determined whether the probe is in contact with the electrode, and the height position of the wafer is known.

In the first measurement judging step, if the capacitance can be measured, it means that the probe is in contact with the electrode.
It is not known whether the height position of the wafer at that time is optimal. Therefore, the wafer is lowered by a predetermined amount in the wafer lowering step, and the capacitance is measured again. In the second measurement judging step, it is determined whether or not the capacitance can be measured. After performing the wafer lowering / measurement instructing step for lowering the wafer, the second and subsequent capacitance measuring steps are repeated again. In this way, it is possible to search for the optimum position of the height of the wafer. Then, in this loop, the probe is eventually separated from the electrode, and the capacitance measurement becomes impossible in the second capacitance measurement step. Therefore, when the capacitance measurement becomes impossible in the second measurement determination step, the wafer lift / end instruction step is performed, whereby the probe separated from the electrode is brought into contact with the electrode again. In this way, the optimum position of the wafer height is determined.

On the other hand, if the capacitance cannot be measured in the first measurement judgment step, it means that the probe is not in contact with the electrode. Therefore, the wafer is raised by a predetermined amount in the wafer raising step. At this time, if the amount of rise of the wafer exceeds the specified amount, this flow is stopped. On the other hand, if the amount of rise of the wafer is within the specified amount, the capacitance measurement is performed again in the third capacitance measurement step, and whether or not the capacitance measurement is possible is determined in the third measurement determination step.

If the capacitance can be measured in the third measurement determination step, it is determined that the probe has contacted the electrode, and the height of the wafer is determined to be the optimum position. On the other hand, if the capacity measurement is not possible in the third measurement determining step, the wafer raising / measuring instructing step of raising the wafer by a predetermined amount is performed again, and the above steps of determining the wafer raising amount are repeated again. In this way, it is possible to search for the optimum position of the height of the wafer. Then, in this loop, the probe comes into contact with the electrode and the capacitance can be measured in the third capacitance measuring step. Then, as described above, the probe is brought into contact with the electrode for the first time when the capacitance measurement becomes possible in the third measurement determination step. This contact position is the optimum position of the wafer height.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One example of an embodiment relating to a wafer prober of the present invention will be described with reference to the schematic configuration diagram of FIG.

As shown in FIG. 1, a wafer prober 11 of the present invention has a stage 41 on which a wafer 31 on which a semiconductor device (not shown) for testing electrical characteristics is formed is mounted.
And a stage drive unit 42 for driving the stage 41 in the X-axis, Y-axis, and Z-axis directions.

Above the stage 41, the wafer 31
Connected to a tester (not shown) for measuring electrical characteristics of the semiconductor device formed on
Are provided. Each probe 21 is usually formed on a probe card (not shown).

Further, a capacitance measuring section 51 electrically connected to each probe 21 and measuring the capacitance between the electrodes by bringing each probe 21 into contact with the electrode 32 is provided.
The capacitance measuring unit 51 determines whether or not the electrode 32 and the probe 21 are in contact with each other based on whether or not the capacitance measurement by the capacitance measuring unit 51 is possible. Is provided with a control unit 61 for instructing the stage driving unit 42.

A light source 71 for illuminating the probe 21 and a CCD image sensor 72 for photographing the probe illuminated by the light of the light source are provided on the side of the stage 41. The CCD image sensor 72 is connected to the control unit 61, and the image information of the probe 21 obtained by the CCD image sensor 72 is sent to the control unit 61. Then, the image processing is performed by the control unit 61, the height of the probe 21 is detected, and the amount of elevation of the wafer 31 is instructed. As described above, the control unit 61 instructs the amount of elevation of the wafer 31 to the stage drive unit 42 of the stage device 43 based on whether or not the electrode 32 and the probe 21 are in contact with each other, and performs image processing on the image information of the probe 21. Based on the processing result, the elevation amount of the wafer 31 is instructed to the stage drive unit 42 of the stage device 43.

Next, the operation of the wafer prober 11 will be described below with reference to FIG.

The upper surface of the electrode 32 with respect to the probe 21, that is, the height of the wafer 31 is adjusted by moving the stage 41 up and down.

First, reflected light generated by irradiating the probe 21 fixed to the probe card with the light source 71 is captured by the CCD image sensor 72 and is recognized by the control unit 61 as image data.

Next, the controller 61 calculates the distance between the tip position of the probe 21 and the surface of the electrode 32 of the wafer 31 using the image data.

Then, based on this distance data, the control unit 61 issues an instruction to move the stage 41 up and down the stage drive unit 42, and drives the stage drive unit 42 to move the stage 4
The probe 1 is moved up and down to automatically position the probe 21 and the wafer 31 at the optimum positions.

Then, by utilizing the fact that a certain amount or more of capacitance exists between the electrodes (measurement pads) of the semiconductor device formed on the wafer 31, for example, the capacitance between the electrodes 32A and 32B is changed to the probe 21 (21A, 21A). 21B), the height of the stage 41 is adjusted to a position where the tip of the probe 21 and the surface of the electrode (measurement pad) 32 are in accurate contact with each other while measuring by the capacitance measuring section 51. The adjustment method will be described with reference to a wafer positioning method described later.

At this time, if there are a plurality of combinations of the probes 21 for performing the capacitance measurement, more accurate positioning can be performed in consideration of variations in the height of the tip of the probe 21 due to deformation or the like.

In the wafer prober 11 described in the above embodiment, the capacity measuring unit 5 is different from the conventional wafer prober.
1 is added, and the wafer 31 is determined depending on whether or not the capacitance between the electrodes can be measured.
The height of the probe 21 is adjusted, so that accurate position detection of the probe 21 is realized even for various probe shapes and gloss levels.
Therefore, the alignment accuracy between the probe 21 and the electrode 32 is improved, and the operation of bringing the probe 21 into contact with the electrode 32 can be completely automated.

Next, an embodiment of the method for positioning a wafer according to the present invention will be described with reference to the flowchart of FIG.

As shown in FIG. 2, in the method of positioning a wafer according to the present invention, a probe electrically connected to a tester is brought into contact with an electrode of a semiconductor device formed on the wafer to test the electrical characteristics of the semiconductor device. This is a wafer positioning method for determining a height position of a wafer in a wafer prober to be used.

That is, in the “first capacitance measuring step” S1, the capacitance between the electrodes of the semiconductor device is measured via the probe. Then, the “first measurement determination step” S2 is performed,
It is determined whether or not the capacitance between the electrodes can be measured in the “first capacitance measuring step” S1. Here, "measurable" means that the capacitance value is obtained by measuring the capacitance between the electrodes of the semiconductor device via a probe.
The case where the capacitance cannot be measured because the electrode and the probe are not in contact with each other, and the case where an error occurs beyond the maximum range of the measuring device.

As a result of performing the "first measurement determining step" S2, if the capacity can be measured, that is, if "Yes", the wafer is lowered by a predetermined amount in the "wafer lowering step" S3. Subsequently, in a “second capacitance measuring step” S4, the capacitance between the electrodes of the semiconductor device is measured via a probe. Next, a “second measurement determination step” S5 is performed,
It is determined whether or not the capacitance between the electrodes can be measured in the “second capacitance measuring step” S4.

As a result of performing the "second measurement judging step" S5, if the capacity can be measured, that is, if "Yes", the wafer is lowered by a predetermined amount in the "wafer lowering / measuring instruction step" S6. Again "second capacity measurement step" S
It instructs that steps 4 and after are performed. On the other hand, the "second
As a result of performing the “measurement determination step S5”, if the capacity measurement is impossible, that is, “No”, the wafer is raised by a predetermined amount by the “wafer elevation / end instruction step” S7 to finish the alignment. To instruct.

On the other hand, as a result of performing the "first measurement determining step" S2, if the capacity measurement is impossible, that is, "No", the wafer is raised by a predetermined amount in the "wafer raising step" S8. . After that, a “step of determining the wafer rising amount R” S9 is performed to determine whether the wafer rising amount is equal to or less than a specified amount. As a result of performing the “determination process of wafer rising amount R” S9, if the wafer rising amount R is equal to or less than the specified amount Rc,
That is, when R ≦ Rc, the “third capacitance measuring step”
In S10, the capacitance between the electrodes of the semiconductor device is measured via the probe. Thereafter, "third measurement determination step" S11
To determine whether or not the capacitance measurement between the electrodes can be performed in the “third capacitance measurement step” S10.

As a result of performing the "third measurement determination step" S11, if the capacity measurement is possible, that is, if "Yes", "end instruction" S12 for instructing the end of the alignment is performed. On the other hand, as a result of performing the “third measurement determination step” S11, if the capacity measurement is impossible, that is, “No”, the wafer is raised by a predetermined amount in the “wafer raising / measurement instruction step” S13. Then, an instruction to proceed to the above-described “determination process of wafer rising amount R” S9 is performed. Also, as a result of performing the above-mentioned “determination process of wafer rising amount R” S9, if the wafer rising amount R exceeds the specified amount Rc, that is, if R> Rc, the calculation is stopped as an error. I do.

In the above-described wafer positioning method, the "first measurement determining step" S2, the "second measurement determining step" S5,
In the "third measurement determination step" S11, it is determined whether the probe is in contact with the electrode by determining whether or not the capacitance can be measured. That is, if capacity measurement is possible,
The probe is in contact with the electrode, and if the capacitance cannot be measured, the probe is not in contact with the electrode. Thus, it is determined whether the probe is in contact with the electrode, and the height position of the wafer is known.

As a result of performing the "first measurement determination step" S2, if the capacitance can be measured, the probe is in contact with the electrode, but the height position of the wafer at that time is optimal. I do not know if there is. Therefore, the wafer is lowered by a predetermined amount in the "wafer lowering step" S3, and the capacitance is measured again. Subsequently, in the "second measurement determination step" S5, it is determined whether or not the capacitance measurement is possible. If the capacitance measurement is possible, the "wafer lowering / measurement instruction step" S6 for lowering the wafer by a predetermined amount again is performed. The "second capacitance measuring step" S4 and subsequent steps are repeated again. In this way, it is possible to search for the optimum position of the height of the wafer.

Then, in the above loop, the probe is eventually separated from the electrode, and the capacitance measurement in the "second capacitance measuring step" S4 becomes impossible. Therefore, the "second measurement determination step" S4
As a result, when the capacitance measurement becomes impossible, the "wafer elevation / termination instruction step" S7 is performed to bring the probe away from the electrode into contact with the electrode again. In this way, the optimum position of the wafer height is determined.

On the other hand, as a result of performing the "first measurement determination step" S2, if the capacitance cannot be measured, it means that the probe is not in contact with the electrode. Therefore, the “wafer raising process”
S8 is performed to raise the wafer by a predetermined amount. At this time, if the amount of rise of the wafer exceeds the specified amount, this flow is stopped by the "stopping process" S14. On the other hand, if the amount of rise of the wafer is within the specified amount, the capacitance measurement is performed again in the “third capacitance measurement step” S10. Then, "3rd
Is performed to determine whether or not the capacity can be measured.

As a result of performing the "third measurement determination step" S11, if the capacitance can be measured, that is, if "Yes", it is determined that the probe has contacted the electrode, and the height of the wafer is set at the optimum position. Judge. On the other hand, as a result of performing the “third measurement determination step” S11, if the capacity measurement is impossible, that is, “No”, the wafer is raised again by the predetermined amount again in the “wafer raising / measurement instruction step” S13. Then, the above-mentioned steps of "determining the wafer rising amount R" S9 and thereafter are repeated again. In this way, it is possible to search for the optimum position of the height of the wafer. Then, in this loop, the probe eventually comes into contact with the electrode, and the capacitance measurement in the “third capacitance measurement step” S9 becomes possible. Then, as described above, as a result of performing the "third measurement determination step" S11, when the capacitance measurement becomes possible, the probe is brought into contact with the electrode for the first time. This contact position is the optimum position of the wafer height.

In the wafer positioning method described with reference to FIG. 2, the “first, second, and third measurement determining steps” S
In steps S2, S5 and S11, it is determined whether or not the capacitance measurement is possible, thereby determining whether or not the probe is in contact with the electrode. That is, if the capacitance can be measured, the probe is in contact with the electrode. If the capacitance cannot be measured, the probe is not in contact with the electrode. Thereby, it is determined whether or not the probe is in contact with the electrode, and the height position of the wafer is known.

In the "first measurement judgment step" S2,
If the capacitance measurement is possible, it means that the probe is in contact with the electrode, but it is not known whether the height position of the wafer at that time is optimal. Therefore, the "wafer lowering step" S
The wafer is lowered by a predetermined amount (for example, 5 μm) by 3 and the capacitance measurement is performed again. Subsequently, in a "second measurement determination step" S5, it is determined whether or not the capacitance measurement is possible. If the capacitance measurement is possible, the wafer is lowered again by a predetermined amount (for example, 5 m) again. I do. Thereafter, the above-mentioned “second capacitance measuring step” S4 and subsequent steps are repeated again. In this way, it is possible to search for the optimum position of the height of the wafer.

Then, in this loop, the probe is eventually separated from the electrode, and the capacitance cannot be measured in the "second capacitance measuring step" S4. Therefore, when the capacitance measurement becomes impossible in the "second measurement determination step" S5, the "wafer elevation / end instruction step" S7 is performed, so that the probe once separated from the electrode comes into contact with the electrode again. That is, the position of the wafer is returned to the position where the probe and the electrode have begun to contact. In this manner, the optimum position of the wafer height is determined.

On the other hand, if the capacitance cannot be measured in the "first measurement judgment step" S2, it means that the probe is not in contact with the electrode. Therefore, in the “wafer raising step” S8, the wafer is raised by a predetermined amount (for example, 5 μm). At this time, if the amount of rise of the wafer exceeds a specified amount (for example, 100 μm), this flow is stopped. It is possible to appropriately set this specified amount. On the other hand, if the rising amount of the wafer is within the specified amount, in the “third capacity measuring step” S10,
The capacitance measurement is performed again, and the “third measurement determination step” S11
Thus, it is determined whether or not the capacity can be measured.

In the "third measurement determination step" S11, if the capacitance can be measured, it is determined that the probe has contacted the electrode, and the height of the wafer is determined to be the optimum position. On the other hand, if the capacity measurement is not possible in the "third measurement determination step" S11, the wafer is again set to the predetermined amount (for example, 5 μm).
After performing the “wafer raising / measurement instructing step” S13 in which the wafer is raised only, the steps after the “wafer raising amount R determining step” S9 are repeated again. In this way, it is possible to search for the optimum position of the height of the wafer. Then, in this loop, the probe eventually comes into contact with the electrode, and the capacitance measurement in the “third capacitance measurement step” S10 becomes possible. Then, as described above, in the "third measurement determination step" S11, when the capacitance measurement becomes possible, the probe is brought into contact with the electrode for the first time. This contact position is the optimum position of the wafer height.

As described above, according to this wafer positioning method, it is possible to determine the optimum position where the probe contacts the electrode, so that the pressure for pressing the probe against the electrode is more accurately and constantly applied. be able to. Therefore, the reliability of the measurement can be improved.

Next, another embodiment of the wafer positioning method of the present invention will be described with reference to the flowchart of FIG. 3 and the schematic configuration diagram of FIG.

As shown in FIGS. 3 and 4, the method for determining the position (position in the height direction) of the wafer 31 according to the present invention uses a plurality of probes 21A, 21B, electrically connected to a tester.
A wafer positioning method for determining the height position of a wafer in a wafer prober for testing electrical characteristics of a semiconductor device by bringing 21C, 21D into contact with electrodes 32A, 32B, 32C, 32D of the semiconductor device formed on the wafer 31. is there.

That is, in the “first capacitance measuring step” S1, the capacitance between the electrodes 32A to 32D of the semiconductor device is measured via the probes 21A to 21D. Here, as an example, the capacitance between the electrode 32A and the electrode 32B is measured by “measurement of the capacitance between AB” S1-1, and “BC” is measured.
Measurement of the capacitance between the electrodes 32B-32C by S1-2
The capacitance between the electrode 32C and the electrode 32D is measured by the “measurement of the capacitance between CD” S1-3, and the capacitance between “D-
Measurement of the capacitance between A "electrode 1-4D-electrode 32 by S1-4
Measure the capacity between A.

Then, the "first measurement determining step" S2 is performed, and the electrode 32 in the "first capacitance measuring step" S1 is processed.
It is determined whether or not the capacity measurement between A to 32D can be performed. Here, “measurable” means that the wafer 3 can be measured via the probes 21A to 21D.
The capacitance between the electrodes 32A to 32D of the semiconductor device formed in 1 is measured to determine the capacitance value. The measurement is impossible, for example, when the capacitance measurement is not performed because the electrode and the probe are not in contact with each other. This is the case where the measurement cannot be performed and the case where an error occurs beyond the maximum range of the measuring device.

As a result of performing the “first measurement determining step” S2, as shown in FIG.
In the case of 2A to 32D, that is, in the case of “Yes”, the wafer is lowered by a predetermined amount in the “wafer lowering step” S3. Subsequently, in a “second capacitance measuring step” S4, the capacitance between the electrodes 32A to 32D of the semiconductor device is measured via the probes 21A to 21D. Here, as one example, the “measurement of capacitance between AB” S <b> 4-1
The capacitance between the A-electrode 32B is measured by the probes 21A and 21B, and the capacitance between the electrode 32B and the electrode 32C is measured by the probes 21B and 21C according to "Measurement of the capacitance between BC" S4-2.
The capacitance between the electrode 32C and the electrode 32D is measured by the probes 21C and 2D in "Measurement of the capacitance between CD and D" S4-3.
1D, the capacitance between the electrode 32D and the electrode 32A is measured by the probe 21 by "measurement of the capacitance between DA" S4-4.
D, 21A. That is, the same measurement as that of the “first capacitance measuring step” S1 is performed.

Next, a "second measurement determining step" S5 is performed, and the electrodes 32A to 32A in the "second capacitance measuring step" S4 are processed.
It is determined whether or not the capacity measurement between 32D can be performed.

As a result of performing the "second measurement determination step" S5, the capacitance measurement is possible between the electrodes 32A to 32D, that is, in the case of "Yes", that is, as shown in FIG. In the case of the state, in the "wafer lowering / measurement instructing step" S6, it is instructed to lower the wafer by a predetermined amount and to perform the steps subsequent to the "second capacity measuring step" S4 again. On the other hand, as a result of performing the “second measurement determination step” S5, the capacitance measurement is impossible between at least some of the electrodes,
That is, in the case of “No”, for example, as shown in (2) of FIG. 4, the probe 21B and the electrode 32B are not in contact, and the other probes 21A, 21C, 21D and the electrode 32
When the wafers A, 32C, and 32D are in contact with each other, the wafer is lifted by a predetermined amount to instruct the end of the alignment in the "wafer lift / end instruction step" S7.

On the other hand, as a result of performing the "first measurement determination step" S2, if the capacitance measurement is impossible at least in part, that is, if "No", for example, as shown in FIG. The probe 21B and the electrode 32B are not in contact with each other.
When the probe 32D and the electrode 32C are in contact with each other and the probe 21D is in contact with the electrode 32D, the wafer is raised by a predetermined amount in the "wafer raising step" S8. Then, the "wafer lift amount R
Judgment Step S9) to judge whether the amount of wafer rise is equal to or less than a specified amount.

Then, "Step of judging wafer rising amount R" S9.
As a result, when the amount of wafer rise R is equal to or less than the specified amount Rc, that is, when R ≦ Rc, the capacitance between the electrodes of the semiconductor device is measured via the probe in the “third capacitance measurement step” S10. Measure. Here, for example, the capacitance between the electrode 32A and the electrode 32B is measured by “measurement of the capacitance between AB” S10-1, and the capacitance between the electrode 32B and the electrode 32C is measured by “measurement of the capacitance between BC” S10-2. After measuring the capacity,
Measurement of capacitance between D ”S10-3, electrode 32C-electrode 3
The capacitance between 2D is measured, and “D-A capacitance measurement” S10
-4, the capacitance between the electrode 32D and the electrode 32A is measured. That is, the same measurement as that of the “first capacitance measuring step” S1 is performed.

Thereafter, a "third measurement determining step" S11 is performed to determine whether or not the capacitance measurement between the electrodes can be performed in the "third capacitance measuring step" S10.

As a result of performing the "third measurement determination step" S11, capacitance measurement is possible between the electrodes, ie, "Ye
s ", that is, when the probes 21A to 21D and the electrodes 32A to 32D are in contact with each other, as shown in FIG. 4A, an" end instruction "S12 for instructing the end of the alignment. I do. On the other hand, as a result of performing the “third measurement determination step” S11, when the capacitance measurement is not possible at least partially, that is, “No”, for example, as shown in (2) of FIG. The other probes 21A, 21C and 21 are not in contact with the electrode 32B.
If D is in contact with the electrodes 32A, 32C, 32D, the wafer is raised by a predetermined amount in the "wafer raising / measurement instruction step" S13, and the process proceeds to the "wafer raising amount R determining step" S9. Make instructions. Further, as a result of performing the “determination process of the wafer rising amount R” S9, the wafer rising amount R
Is larger than the specified amount Rc, that is, if R> Rc, an “error step” S14 for stopping the calculation according to this flowchart is performed.

In the wafer positioning method described with reference to FIGS. 3 and 4, the same operation and effect as those of the flowchart described with reference to FIG. 2 can be obtained, and the distance between the probes 21A to 21D and the electrodes 32A to 32D varies. Even so, the height position of the wafer 31 can be determined so that each of the probes 21A to 21D is in contact with each of the electrodes 32A to 32D.

[0062]

As described above, according to the wafer prober of the present invention, since the capacitance measuring section for measuring the capacitance between the electrodes via the probe is provided, the contact between the probe and the electrode can be measured by the capacitance measurement. Can be detected depending on whether or not.
In addition, since a control unit for issuing a command to control the height of the wafer based on whether or not the capacitance can be measured is provided, the height position of the wafer can be adjusted depending on whether or not the capacitance can be measured.
Therefore, the positioning accuracy can be dramatically improved. Therefore, it is possible to eliminate the operator's correction work of the alignment, and to realize the automation of the alignment of the probe completely.

According to the wafer positioning method of the present invention,
The contact state between the probe and the electrode can be determined based on whether or not the capacitance between the electrodes can be measured, and the wafer position at which the contact between the probe and the electrode is optimal can be automatically determined. Automation can be realized. In addition, since the pressure for pressing the probe against the electrode can be more accurately and constantly applied, the reliability of measurement can be improved.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing an example of an embodiment relating to a wafer prober of the present invention.

FIG. 2 is a flowchart illustrating an example of an embodiment of a wafer positioning method according to the present invention.

FIG. 3 is a flowchart showing another embodiment according to the wafer positioning method of the present invention.

FIG. 4 is a schematic configuration diagram illustrating another embodiment shown in FIG.

FIG. 5 is an explanatory diagram of a wafer prober according to a conventional technique.

[Explanation of symbols]

11 wafer prober, 21 probe, 31 wafer, 32 electrode, 43 stage device, 51 capacitance measuring unit, 61 control unit

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2G011 AA15 AC09 AC14 AE03 2G032 AA00 AF02 AF04 AL03 AL04 4M106 AA01 AA02 AA07 AA20 AB12 AC07 AD07 BA01 BA14 CA11 CA50 DB04 DB07 DD05 DD06 DD10 DD23 DJ05 DJ07 DJ11 DJ18 DJ20 5F03 CA MA33

Claims (3)

[Claims] A probe connected to a tester for measuring an electrical characteristic of the semiconductor device, the probe being in contact with an electrode of the semiconductor device formed on the wafer; A wafer prober having a stage device capable of causing the probe to be electrically connected to the probe, wherein the capacitance is measured by contacting the probe with the electrode and measuring the capacitance between the electrodes via the probe. And a control unit that determines whether the electrode and the probe can be in contact with each other based on whether the capacitance measurement unit can measure the capacitance, and instructs the stage device on the amount of elevation of the wafer based on whether the electrode can be contacted. A wafer prober comprising: 2. A probe electrically connected to a tester is brought into contact with an electrode of a semiconductor device formed on a wafer to determine a height position of the wafer in a wafer prober for testing electrical characteristics of the semiconductor device. A wafer positioning method, comprising: a first capacitance measuring step of measuring a capacitance between electrodes of the semiconductor device via the probe; and determining whether or not the capacitance between the electrodes can be measured in the first capacitance measuring step. A first measurement judging step to perform; a wafer lowering step of lowering the wafer by a predetermined amount when the capacitance measurement is possible as a result of the first measurement judging step; A second capacitance measuring step of measuring the capacitance between the electrodes of the device via the probe; and a second determining whether or not the capacitance between the electrodes can be measured in the second capacitance measuring step. When the capacity measurement is possible as a result of the measurement determination step and the second measurement determination step, the wafer instructing to lower the wafer by a predetermined amount and to perform the second capacity measurement step and thereafter again As a result of the lowering / measuring instruction step and the second measurement judging step, when the capacity measurement is impossible, a wafer raising / ending instruction step of instructing termination of alignment by raising the wafer by a predetermined amount. A step of raising the wafer by a predetermined amount when the capacitance measurement is impossible as a result of the first measurement determination step; A step of determining the amount of wafer rise to determine whether or not the following, and a result of the step of determining the amount of wafer rise, when the amount of rise of the wafer is equal to or less than a prescribed amount, the capacitance between the electrodes of the semiconductor device through the probe hand A third capacitance measuring step of measuring; a third measuring judging step of judging whether or not the capacitance between the electrodes can be measured in the third capacitance measuring step; and a capacitance measurement as a result of the third measuring judging step. When possible, as a result of the end measurement step for instructing the end of the alignment and the third measurement determination step, if the capacity measurement is impossible, the wafer is raised by a predetermined amount to raise the wafer. A wafer elevating / measuring instructing step for giving an instruction to proceed to the amount estimating step; and a stopping step for stopping the computation as an error when the wafer elevating amount exceeds a specified amount as a result of the wafer elevating amount determining step. A wafer positioning method, comprising: 3. The wafer positioning method according to claim 2, wherein in the first capacitance measuring step, a capacitance between a plurality of electrodes of the semiconductor device is measured via the probe, and the first measurement determining step is performed. In the first capacitance measurement step, it is determined whether or not the capacitance measurement between the electrodes can be performed. As a result of the first measurement determination step, if the capacitance measurement is possible between the electrodes, the wafer lowering step is performed. After doing
Measuring the capacitance between the plurality of electrodes of the semiconductor device via the probe in the second capacitance measurement step;
It is determined whether or not the capacitance measurement between the electrodes in the second capacitance measurement step is possible in the measurement determination step.If the capacitance measurement is possible between the electrodes as a result of the second measurement determination step, Performing the wafer lowering / measuring instructing step and subsequent steps; and, as a result of the second measurement judging step, when the capacitance measurement is not possible at least partially, performing the wafer raising / ending instructing step; As a result of the measurement judging step, if the capacitance measurement is not possible at least in part, after the wafer elevating step is performed, the steps after the wafer elevating amount judging step are performed. In the step, the capacitance between the plurality of electrodes of the semiconductor device is measured via the probe. In the third measurement determination step, it is determined whether or not the capacitance between the electrodes can be measured. Measurement result, capacity measurement If it is possible between the electrodes, the termination instruction step is performed. If the result of the third measurement determination step is that capacitance measurement is not possible at least partially, the wafer raising / measurement instruction step is performed. A method for positioning a wafer, comprising: