JPH08274134A - Method for marking defective element - Google Patents

Abstract

PURPOSE: To easily adjust the size and position of a mark put on a defective element by correcting the relative position of the mark in a two-dimensional plane when the position is not appropriate or the relative height of the mark when the size of the mark is not appropriate. CONSTITUTION: A control means 35 which corrects and controls the relative positional relation between the pad electrode of a wafer 1 and probe 3 and overdriving amount of a placing stage 2 based on the recognized result of a recognizing means 30 is provided. The control means 35 is composed of a CPU 33 and ROM 36 which stores various kinds of arithmetic information. The CPU 33 controls the movement of the stage 2 in the X-, Y-, and Z-axis directions and θ-direction by calculating the drive amount of the stage 2. Therefore, an appropriate mark can be accurately put on a defective element for sorting defective elements from defectless elements.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a defective element marking method for marking a defective element determined to be defective after inspecting the electrical characteristics of the element to be measured with a probe needle.

[0002]

2. Description of the Related Art A probe device, for example, a probe device for a semiconductor wafer, contacts a probe needle with an electrode pad of the device to measure electrical characteristics of a large number of devices on the wafer, and uses the probe needle as a tester. By connecting, the measurement is performed.

Usually, the wafer is supported on a mounting table by a vacuum chuck or the like, and the mounting table is controlled to move in the θ direction, which is the circumferential direction of the X, Y axis directions and the Z axis, so that the electrodes of the elements are controlled. The pad and the probe needle are aligned with each other, and the probe needle and the electrode pad are brought into contact with each other by mounting a wafer and raising the mounting table.

Further, based on the measurement result of the electrical characteristics using the probe needle and the tester, the defective element is configured to be marked by the scratch marker method or the inker method.

Here, the above-mentioned alignment between the electrode pad and the probe needle is important for performing measurement with a very small measurement error, and automation has been strongly demanded in order to perform the measurement with high accuracy. .

Therefore, a proposal has been made to automate this kind of alignment without relying on the visual observation of an operator (JP-A-58-169922, JP-A-59-5641, JP-A-60-24029). Kaisho 60
-24030, JP 61-15340, and JP 62-16018).

Further, the present applicant has also made a proposal for automating the above-mentioned alignment (Japanese Patent Application No. 60-69554, Japanese Patent Application No. 60-69554).
62-106027).

[0008]

The above-mentioned conventional proposals all perform only the alignment of the mounting table based on the probe marks of the probe needles, and only the alignment between the probe needles and the electrode pads. It was

Incidentally, in addition to the above-mentioned alignment, adjustment of the contact pressure of the probe needle is also important. If the contact pressure is too large, the life of the probe needle will be shortened, or the wafer and probe needle will be damaged. There is. On the other hand, if the contact pressure is too small, an oxide film is usually formed on the wafer, and therefore the oxide film cannot be pierced by the probe needle, resulting in electrical contact failure and reliable measurement. There is a problem that can not be executed.

Further, even if accurate measurement is possible, if the above-mentioned defective element is not properly marked, it is not possible to separate good elements from defective elements after the elements are separated, and the measurement is wasted. Become.

Therefore, an object of the present invention is to solve the above-mentioned conventional problems and provide a new method for adjusting the position of the probe needle and adjusting the contact pressure, and at the time of marking. The purpose of the present invention is to provide a marking method for a defective element by which the size and position of the marking on the defective element can be easily performed by applying the method to the adjustment.

[0012]

According to the present invention, a device to be measured on a substrate to be measured is measured, and a defective device determined to be defective based on the measurement result is changed to a defective device to be marked by a marking means. In the marking method, the image of the marking mark on the defective element is picked up by the image pickup means, and when the position of the marking mark is different from the proper value,
When the relative position of the defective element and the marking means on the two-dimensional plane is corrected and the size of the marking mark is different from the proper value, the defective element in the direction orthogonal to the two-dimensional plane. And a relative height position between the marking means and the marking means is corrected.

Preferably, the substrate to be measured is movable in X and Y axis directions which are orthogonal coordinates of a two-dimensional plane, a Z axis which is orthogonal to the two dimensional plane, and a θ direction around the Z axis. When the marking mark is placed on a different mounting table and the position of the marking is different from the proper value, the X, Y-axis directions of the mounting table,
When the relative position on the two-dimensional surface is corrected by the movement in the θ direction and the size of the marking mark is different from the proper value, the relative height is changed by the movement of the mounting table in the Z-axis direction. The position can be modified.

[0014]

The method of the present invention is characterized in that the marking position and size when a defective element is marked on the substrate to be measured are corrected by detecting marking marks.

For example, when the relative positional relationship between the defective element and the marking means is set to an appropriate position in the X, Y, Z axis directions and the θ direction, the position and size of the marking mark are stored in advance. By comparing the marking trace information, which is the appropriate value, with the position and size information of the marking trace recognized by the imaging unit, the alignment position correction information and the Z direction position correction information are obtained. be able to.

By the way, the marking position can be corrected by correcting the position of the defective element and the marking means on the two-dimensional surface, and the position correction in the X, Y axis directions and the .theta. Direction may be executed.

On the other hand, the size of the marking trace is determined by the stop position of the mounting table in the Z direction, that is, the height between the defective element and the marking means, and Z is corrected by the correction information based on the size of the marking trace. By correcting the stop position in the direction, an appropriate marking size can be obtained. Further, by obtaining the height in the Z direction that electrically turns on / off and using it together with the information, the size of the marking with higher reliability can be obtained.

As described above, in the method of the present invention, a new method of adjusting the contact pressure and the alignment position from the probe mark of the probe needle is applied to the correction of the marking position and the size.

The position of the marking can be adjusted by correcting the position on the two-dimensional surface of the mounting table, and the size of the marking can be adjusted by adjusting the position of the mounting table in the Z direction in both the scratch marker method and the inker method. The alignment operation and control operation are exactly the same, the marking trace is imaged by the image pickup means, compared with the appropriate marking trace information, and then the position of the mounting table etc. is controlled based on this correction information, In addition to the needle alignment, the marking position and size can be automatically corrected.

Incidentally, such a correction operation may be executed during the measurement of the substrate to be measured, or the position of the mounting table or the like may be corrected in advance by a confirmation dummy substrate before the measurement. good.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, a semiconductor wafer probing method in the pre-process of the method of the present invention will be specifically described with reference to the drawings.

In this probing method, the alignment position and the overdrive amount of the mounting table are corrected and controlled based on the position and size of the needle trace with respect to the pad area of the element to be measured.

First, the probe device will be described.
The wafer 1 is supported on a mounting table 2. The mounting table 2 has orthogonal coordinate axes on the surface of the mounting table as X and Y axes, and the vertical direction is Z.
Axis, when the circumferential direction of this Z axis is the θ direction, X, Y,
It is movable in the Z-axis direction and the θ direction.

Further, the mounting table 2 is supported by a slide portion 12 which is movable along a bolt shaft 11 which is rotationally driven by a motor 10, and has a reading position indicated by a solid line in FIG. 1 and a chain line in FIG. It is movable over the measurement position indicated by.

At the measuring position, the probe needle 3 is attached to the probe card 4, and the ring insert 5 of the probe card 4 is arranged in the inner hole of the support ring 6.

The ring insert 5 and the support ring 6 are rotatable, and the handle 5a provided on the outer peripheral portion of the ring insert 5 is interlocked with the peripheral rotation mechanism 20.

Above the measurement position, a television camera 31 composed of image pickup means such as ITV is provided.
The trace of the needle added to the electrode pad of the chip on the wafer 1 is imaged. The television signal from the television camera 31 is input to the needle trace discriminator 32, where it is compared with a predetermined threshold level to discriminate the presence or absence of the needle trace, and the needle trace information is stored in the RAM 34 via the CPU 33.
It is designed to be stored in each address. The television camera 31, needle mark discriminator 32, CPU 33 and RAM
34 is an example which comprises the recognition means 30.

Further, there is provided control means 35 for correcting and controlling the relative positional relationship between the pad electrode of the wafer 1 and the probe needle 3 and the overdrive amount of the mounting table 2 based on the recognition result of the recognition means 30. ing. The control means 35 is composed of the CPU 33 and a ROM 36 which stores various calculation information. And the R
The CPU 33 calculates the drive amount based on the information stored in the OM 36, and controls the drive in the X-, Y-, Z-axis directions and the θ direction described above.

Next, the operation will be described.

First, the initial alignment when the probe needle 3 is replaced will be described. The mounting table 2 on which, for example, an aluminum vapor-deposited substrate on which an initial chip for confirming the needle traces is formed is raised in the Z direction until the probe needles 3 come into contact, and then lowered. The initial chip to which the probe needle mark is added is moved together with the mounting table 2 for a certain distance L by driving the motor 10, and is set at the measurement position.

Then, at the measurement position, the television camera 3
By 1, the relationship between the position of the initial chip and the trace of the needle added to the initial chip is imaged.

That is, the position of the needle trace with respect to the initial chip can be recognized by accessing the RAM 34 which stores the output of the needle trace discriminator 32 for each address.

That is, as shown in FIG.
4 in the area of the electrode pads 40a, 40b on
1a and 41b are stored (in general, this kind of needle trace has an elliptical shape, but is schematically illustrated as a rectangular shape for convenience of description).

First, the recognition of the needle trace will be described with reference to the rows and columns shown in FIG. 2. The first row is scanned as shown by the arrow 42 to search up to the last row. And
After confirming "1" on the nth line where the needle trace exists and storing the line number, the line address where "1" exists is searched in the same manner.

By scanning the column side as well,
Search for the row address where the needle trace exists.

As described above, the area where the needle mark exists can be confirmed by the binarized image data.

The outer shapes of the needle traces 41a and 41b can be recognized from the address where the "1" exists. Then, the needle trace centers R1 and R2 shown in FIG. 3 can be calculated from this outer shape. This needle trace center R1,
If R2 is obtained, known electrode pads 40a and 40b
Center Q and P positions (stored in the ROM 36)
It is possible to calculate the deviation amount of the needle trace centers R1 and R2 with respect to each of the X and Y axis directions.
It is possible to obtain the alignment correction amounts in the X and Y directions.

Next, the rotation amount is calculated. Here, the pads 40a and 40b at two locations in the chip shown in FIG.
In, the center-to-center distance OP of the pad and the shape of the chip are set values for the ROM 36. And
A straight line passing through the needle trace centers R1 and R2 intersects a straight line OP representing the distance between the centers of the pads. Therefore, as shown in FIG. 3, the intersection of the two straight lines is set to Q, and the distance of the X component and the distance of the Y component of R1 and R2 can be recognized by the recognition means 30, so that the needle trace center R1, It is possible to calculate the distance between R2. Therefore, the inclination α of these two straight lines can be calculated, and the ring insert 5 to which the probe needle 3 is fixed is rotated by the drive of the peripheral rotation mechanism 20 to perform the alignment correction by α degrees in the θ direction. As a result, the correction of the rotation direction can be executed. Note that this correction may be performed by rotating the mounting table 2 in the θ direction.

As described above, the relative positional relationship between the electrode pad and the probe needle 3 can be automatically executed in the X, Y and θ directions.

Next, the correction of the contact pressure based on the trace of the needle will be described.

This contact pressure is reflected in the sizes of the needle marks 40a and 40b. Therefore, the size of the needle trace can be recognized by calculating the area of the entire area of the address where "1" is present where the needle trace exists.

Then, by comparing with predetermined size information stored in the ROM 36 in advance, it is possible to recognize how large or small the size is larger than the reference size.

The correction of the contact pressure can be executed by changing the stop position of the mounting table 2 in the Z direction. That is, the contact pressure of the probe needle 3 is determined by the amount of overdrive of the mounting table 2 after the probe needle 3 contacts the chip. Therefore, if the needle trace is larger than the reference, the overdrive amount is reduced and the needle trace is reduced. If is smaller than the standard, you can correct it by increasing the overdrive amount. Further, by obtaining the height in the Z direction that electrically turns on / off and using it together with the information, a contact pressure with higher reliability can be obtained.

As described above, the alignment and the automatic correction of the contact pressure of the probe needle can be executed.

Such a correction operation is performed when the needle trace confirmation substrate is placed and executed, and also when the semiconductor wafer 1 is actually placed on the placing table 2 and the probe inspection is performed. You can also In this case, it is complicated to execute the above correction each time the electrical characteristic inspection of each chip is completed.

Therefore, since this type of probe device has an inspection function for detecting defective needle marks, for example, when it is judged that defective needle marks are caused by this inspection function (for example, 5 consecutive chips are judged to be defective chips). In some cases), the above-described correction operation may be executed.

By doing so, it becomes possible to effectively execute the alignment correction and the adjustment of the contact pressure during the execution of the probe inspection.

Regarding the position correction in the X and Y axis directions θ described above, Japanese Patent Application No. 62-106 previously proposed by the present applicant.
The method disclosed in 027 can also be adopted.

Next, the method of the embodiment of the present invention applied to the position adjustment of the marking and the size adjustment of the marking by the same procedure as the alignment and the correction of the contact pressure in the probing method described above will be described.

Marking of defective elements is carried out by a scratch marker shown in FIG. 4, for example. This scratch marker has a solenoid 51 at one end of the holder 50.
And a sleeve guide 52 is supported at the other end. The solenoid 51 supports the piston 53 so that it can be inserted and removed by energization. On the other hand, a scratch needle 54 is supported and seated on the sleeve guide 52, and the movement of the piston 53 when the solenoid 51 is energized causes the scratch needle 54 to move to the sleeve guide 5.
It is configured to perform marking by protruding further than 2 and contacting the chip.

Here, also in the case of the above-mentioned marking, as with the probe needle 3 described above, it is necessary to align the position, and for example, as shown in FIG. It is necessary to prevent the situation.
Further, this marking is read by a television camera or the like after the probe inspection and is used for judging the quality of the chip, and it is necessary to change the size of the marking according to the size of the chip. That is, it is not necessary to make an excessively large marking with respect to the chip area as shown in FIG. 5 (b). On the other hand, as shown in FIG. There is a problem that it is overlooked in the pattern recognition.

Therefore, if the chip on which the marking has been carried out is moved to the above-mentioned measurement position, the marking mark is recognized by the television camera 31 or the like which is the image pickup means, and the position and the contact pressure are similarly corrected. The adjustment work that was conventionally performed manually can be automated, and the burden on the operator can be greatly reduced.

This kind of marking may also be executed by a method called an inker method, which means that the ink in the ink fountain is ejected by the movement of the piston by energizing the solenoid. The alignment is similar to the scratch system, and the size of the marking can be corrected by the distance from the ink ejection end to the chip, that is, the moving position of the mounting table 2 in the Z direction.

The present invention is not limited to the above embodiment, but various modifications can be made within the scope of the gist of the present invention.

[0055]

As described above, according to the present invention, the position and size of the marking are corrected based on the information of the marking mark, so that the marking mark suitable for later selection of non-defective products and defective products can be obtained. Can be accurately written for a defective element.

[0056]

[Brief description of drawings]

FIG. 1 is a schematic explanatory view for explaining an embodiment in which the present invention is applied to a semiconductor wafer probe apparatus.

FIG. 2 is a schematic explanatory view for explaining an operation of detecting a positional deviation of a needle mark in X, Y axis directions and θ direction.

FIG. 3 is a schematic explanatory diagram for explaining an operation of detecting a positional deviation of needle traces in X, Y axis directions and θ directions.

FIG. 4 is a schematic explanatory diagram of a scratch marker which is an example of marking means.

FIG. 5 is a schematic explanatory diagram for explaining a positional deviation of markings and a difference in size.

[Explanation of symbols]

 1 substrate to be measured 2 mounting table 31 imaging means 50 to 54 marking means

Claims (4)

[Claims] 1. A method of marking a defective element in which a device to be measured on a substrate to be measured is marked by a marking means with respect to a defective element determined to be defective based on the measurement result. If the position of the marking trace is different from the proper value, the relative position of the defective element and the marking means on the two-dimensional plane is corrected to obtain an appropriate value. On the other hand, when the size of the marking traces is different, the relative height position between the defective element and the marking means in the direction orthogonal to the two-dimensional plane is corrected to mark the defective element. Method. 2. The substrate to be measured has X and Y axis directions which are orthogonal coordinates of a two-dimensional plane and Z which is orthogonal to the two-dimensional plane.
Axis and the mounting table movable in the θ direction around the Z-axis, and when the position of the marking mark is different from the proper value, the X-, Y-axis directions of the mounting table, θ By moving in the direction
Correcting the relative position on the two-dimensional surface, and when the size of the marking mark is different from an appropriate value, correcting the relative height position by moving the mounting table in the Z-axis direction. The method for marking a defective element according to claim 1, wherein: 3. The correction according to claim 1, wherein when the size or position of the marking mark with respect to the defective element is continuously generated over a plurality of elements, the correction is performed. Probing method. 4. A marking trace information confirmation substrate is placed on the mounting table, and the relative position on the two-dimensional surface and the position in the Z-axis direction are corrected before the measurement of the substrate to be measured. The probing method according to claim 2, wherein the probing method is executed in advance.