JPH0677296A - Probing electrode for integrated circuit element wafer - Google Patents

Abstract

PURPOSE:To provide a probing electrode for integrated circuit element wafer which is incorporated to an inspection apparatus or an aging apparatus using, as a sample to be inspected, a semiconductor integrated circuit element which is in such a condition as being raised on a water or is being cut into pellet including a plurality of elements and enable high precision and highly reliable contact with such a sample. CONSTITUTION:A probing electrode for integrated circuit element is connected, by a connecting means 8 formed by a flexible printed circuit board, to contact blocks 4 having contact group corresponding to arrangement of electrode part, that is, electrode portion 3 under test of an IC pattern raised on the surface of a wafer 2 set on a surface plate 1 and a circuit substrate 7 for connection with the main apparatus. On the other hand, a plurality of contact blocks 4 are bonded with a movable base plate 10 having a sufficient rigidity through a buffering part 11 formed by a material having flexibility and elasticity such as a synthetic rubber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inspection device for semiconductor integrated circuits (hereinafter referred to as IC) and an aging device (hereinafter, both are collectively referred to as a main device), and a pellet including a plurality of IC patterns is provided. The purpose is to make highly accurate and highly reliable contact with the electrode portion (hereinafter referred to as the measured electrode portion) on the IC pattern in the wafer state (hereinafter referred to as the subject) before being cut into pellets or pellets. The present invention relates to a measurement electrode for an integrated circuit device wafer (hereinafter referred to as a measurement electrode).

[0002]

2. Description of the Related Art Conventionally, a wafer related to an IC is cut into individual pellets, which are inspected or aged in a process after mounting on a lead frame and packaging, and the characteristics of pellets addressed to one piece. There was also a device for sequentially measuring, but it was not suitable for mass production because it took a long time for inspection.

[0003]

Therefore, the conventional measuring electrode does not need to be specially devised in order to meet the conventional technology in terms of design and work, but on the other hand, much time and labor are required for mounting and removing the finished product IC. However, if a defective product is produced at the same time, all the processes up to that point are wasted, which is a big pain especially for varieties with low yields.

The object of the present invention is to package I
In order to eliminate the waste of the process when a defective product is detected for C, it is possible to measure at once a plurality of integrated circuit devices grown on a wafer and pellets containing a plurality of devices. By doing so, it is possible to prevent waste of intermediate processes and improve production efficiency significantly.
By expanding the configuration of the main device, it is possible to determine the distribution state of defective portions on a wafer, and to retroactively determine process defects such as defective IC pattern masks. It is an object of the present invention to provide a measuring electrode which can be expected to have a wide range of applications such as being applicable to a defect inspection device other than an IC wafer such as a liquid crystal display device having a fine structure electrode.

[0005]

As a result of various studies to solve the above problems, the present inventor has performed a wafer on which a plurality of IC patterns have been grown, or a specimen cut into pellets containing a plurality of elements. For the measurement electrode attached to the main device to be inspected or aged, the contact block and the movable base related to the measurement electrode can be contacted in order to make contact with the electrode to be measured with high accuracy and reliability. A buffer part having elasticity and flexibility is interposed between the two, and the structure and the pressure of the fluid are used to enable fine movement in whole and in part related to the contact block. As a result, by providing a measurement electrode characterized in that each contact block can follow the surface state of the subject, and the structure is such that precise contact with the subject can be achieved. It is those that have achieved the serial purpose.

[0006]

According to the present invention, a buffer portion having elasticity and flexibility is interposed between the contact block and the movable base, and the characteristics of the structural material, the pressure of the fluid, etc. are utilized to make the surface plate and the object to be examined. With respect to the distance between the movable base and the contact block or the measurement electrode, the contact block and the measurement electrode can closely follow the surface condition of the subject by adopting a structure that allows fine movement in whole or in part. It was possible to obtain a structure that enables precise and highly reliable contact with the subject.

[0007]

[Examples] At present, the condition of an IC wafer is such that the distance between adjacent IC patterns is about 20 μm and the distance between electrodes is about 30 μm. Tends to become.

For example, on an 8-inch wafer, several hundred to several thousand IC patterns are grown per wafer.
Even if the number of measured electrodes is about several tens per pattern, the number of electrodes per wafer is several thousand to several 10,000.
Therefore, how to make a measurement electrode configuration is a key to highly reliable contact with such a number of measurement targets.

The present invention will be described below with reference to the embodiments shown in FIGS. In each figure, FIG. 1 is a cross-sectional view showing an embodiment of the measuring electrode and the test object according to the present invention, FIG. 2 is a cross-sectional view showing the structure of a contact block, and FIG. 4 is a cross-sectional view of a contact block configured to secure the above-mentioned structure, and FIG. 4 is a cross-sectional view showing an embodiment of a mechanism configured to finely adjust the mutual gap and parallelism between the movable base and the subject or surface plate. FIG. 5 is a cross-sectional view showing an embodiment of the present invention in which a wafer and a contact block are brought into contact with each other by utilizing the pressure of a fluid, and FIG. 6 is a support film having flexibility and elasticity to support a measurement contact. 7 is a cross-sectional view of an example configured to
FIG. 4 is a cross-sectional view of an example in which the measurement contact is formed of a thin film contact having flexibility and elasticity.

As shown in FIG. 1, the relationship between the IC wafer of the subject and the movable portion A of the measuring electrode is as shown in FIG. 1 of the measuring electrode portion 3 on the IC pattern grown on the surface of the wafer 2 placed on the surface plate 1. The contact block 4 having a contact group corresponding to the arrangement is formed by a technique such as printed circuit board manufacturing, and is formed on the contact surface with the wafer 2 on the base 4A made of an insulating material such as plastic or ceramic as shown in FIG. The plurality of measuring contacts 5 are connected to the back surface round 6 by a technique such as through hole.

The backside round 6 and the circuit board 7 for connecting to the main device are connected by a connecting means 8 such as a flexible printed circuit board. The connecting means 8 has a one-to-one correspondence with the contact block 4. It is not necessary, and some of the contact blocks 4 may be collectively connected to the circuit board 7.

The circuit board 7 has a contact portion 7'provided at the end thereof.
It is connected to the main device by the connector 9 and is composed of a multilayer printed circuit board due to the fact that many wirings are intricate.
Since the operation speed becomes slower due to the influence of the capacitance of the input / output unit of the subject and the distributed capacitance between wirings, it is usually necessary to mount a driver circuit such as a data or address bus line or a timing signal line on the substrate.

On the other hand, the plurality of contact blocks 4 are buffer portions 1 made of a flexible or elastic material such as synthetic rubber.
1 is bonded to the movable base 10 configured to have sufficient rigidity.

With this structure, the contact block 4 is individually stabilized by the elasticity of the buffer portion 11 following the surface condition of the wafer 2, so that the contact can be secured and the necessary contact pressure can be obtained.

The contact block 4 is manufactured by a precision printed circuit board manufacturing technique if the arrangement pitch is relatively coarse. As described above, if the element pattern spacing on the wafer is smaller than several tens of μm, the IC is manufactured. It is grown on a semiconductor substrate such as silicon by a manufacturing technique and is reinforced by a reinforcing material when the rigidity is insufficient. In any case, the measuring contact 5 on the contact block 4 is made of a material such as gold. Composed of thick plating.

Further, each of the measuring contacts 5 of the contact block 4 is a fine metal rod having a contact part at the bottom as shown in FIG. 3, and the upper part is made of an elastic material or a flexible material such as adhered to the connecting means 8. It may be configured to ensure contact with an object having a poor surface condition by holding it directly or indirectly and allowing it to move up and down freely in the hole formed in the base 4A.

The connecting means 8 can be replaced by a flat cable-like one composed of a thin wire or an ordinary wiring, and the contact block 4 is not divided and is common to an object which does not require precision. It can also be configured by a printed circuit board.

Regarding the contact between the measurement contact 5 and the electrode part 3 to be measured, the distance adjustment between the wafer 2 and the movable part A has a great influence, but as a method for finely adjusting the relationship between them, During measurement, the movable part A is lowered to a certain distance from the wafer 2 through the movable base 10 which is interlocked with an external mechanism, and then, the wafer 2 is moved by the non-contact type displacement sensor 17 as shown in FIG. And the value is input to a controller installed externally and calculated, and the eccentric cam 18 linked with a servo-type motor 19 with a built-in reduction gear is driven to adjust the fine distance. It is possible to install the mechanism at a plurality of corners of the surface plate 1 and the movable base 10.

Further, with respect to the above-mentioned additional mechanism installed at a plurality of corners of the surface plate, by adjusting the eccentric cam 18 so that the distance measured by the displacement sensor 17 becomes the same value, the surface plate 1 or the wafer 2 is formed. It is also possible to control the parallelism between the movable parts A.

In the above example, the contact pressure state of the contact block 4, the wafer 2 and the movable portion A was determined almost by the elasticity and flexibility of the buffer portion 11 and the descending distance of the movable portion A. A fluid such as a gas or a liquid can be used as a method for more finely adjusting.

FIG. 5 shows an example of the structure in which gas is used as the fluid, and the gas pumped from the external pump is empty.
2 from the pipe portion 12 'provided in the second base 2, and then into the space composed of the movable base 10, the buffer portion 11 and the contact block 4 through the ventilation hole 13 provided through the movable base 10 and the circuit board 7. Therefore, the position of the contact block 4 can be finely adjusted by adjusting the pressure.

In this case, in order to maintain the airtightness between the circuit board 7 and the void 12, it is necessary to use a seal 14 made of an elastic material such as synthetic rubber.

Therefore, after the movable part A is mechanically brought close to the semiconductor wafer 2, the contact block 4 is slightly projected by applying a gas having an appropriate pressure to the vent hole 13 to make the electrode part to be measured. It is possible to adjust the adhesiveness with respect to 3 and the contact pressure.

In the present embodiment, the gas having the same pressure is applied to all the vent holes 13 by means of the air holes 12, but the air holes 12 are not used, and individual pipes are provided for each of the air holes 13. The contact timing and contact pressure of each contact block 4 can be adjusted by adjusting the respective applied pressures.

With respect to the measuring contacts 5 of the contact block 4, if the individual measuring contacts 5 are moved by the pressure of the fluid and the contact pressure with the object is obtained by the structure shown below, the individual operating range is widened. Therefore, it is possible to improve the accuracy of copying with the surface of the subject.

That is, FIG. 6 shows a structure in which the measuring contact point 5 is supported by a supporting film 15 made of an elastic or flexible material such as synthetic rubber.
5 is configured so that the deformation of each measuring contact 5 is interlocked with each measuring contact 5. In FIG. 7, the portion corresponding to the measuring contact 5 is made of a flexible or elastic metal such as gold or beryllium. The thin film contact 17 is connected to the back surface contact 6 through a through hole or the like, and the portion is projected by the pressure of the fluid flowing from the opening 4A 'provided in the base 4A.

Further, as an alternative to the measuring contact 5, a flowable conductor is held in a capillary made by, for example, a through hole technique, and the degree of protrusion due to the surface tension is controlled by the pressure of the fluid. Alternatively, a method using an electrical contact technique using a micromachine which has been rapidly developed in recent years may be considered.

Although the above description uses positive pressure air, all of these use negative pressure, that is, the vent holes 13 are opened to the atmospheric pressure, and the other parts are airtightly constructed. Needless to say, it is possible that the air is sucked by a vacuum pump or the like and the pressure thereof is adjusted to improve the scanning accuracy with the surface of the subject.

In the present embodiment, the buffer portion 11 is made of a material having elasticity and flexibility such as synthetic rubber. However, this may be a diaphragm or bellows-like member made of a metal such as beryllium or a thin plate such as plastic. It is self-evident that it can be used.

Further, for the purpose of avoiding the complexity of the apparatus when the measuring contact 5 and the measured electrode portion 3 are automatically aligned, the movable portion A and the surface plate 1 and the wafer 2 are not mechanically separated. In some cases, it may be configured such that a unit assembled in advance by hand is installed in the main device.

[0031]

According to the IC tester and the aging device to which the measuring electrode for the integrated circuit wafer according to the present invention is applied,
Since it is possible to inspect the state of IC pellets and the state of wafers before cutting into pellets, waste of intermediate steps can be prevented in advance compared with the case of inspection after packaging, and production efficiency is improved. In addition to improving dramatically,
By considering the configuration of the device using the electrode,
Since it is possible to determine the distribution state of the defective portion on the wafer, there is a great merit that a defect in a retrospective process such as a defect of the IC pattern mask can be detected. Further, the measurement electrode according to the present invention is A liquid crystal display device having an electrode with a similar fine structure as a subject I
It can be applied to defect inspection devices other than C wafers, and can be expected to have a wide range of uses.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an embodiment of a measuring electrode and a subject according to the present invention.

FIG. 2 is a cross-sectional view showing the structure of a contact block.

FIG. 3 is a cross-sectional view of a contact block configured to ensure contact with a subject having a poor surface condition.

FIG. 4 is a cross-sectional view showing an embodiment of a mechanism configured to perform fine adjustment of mutual clearance, parallelism, and the like between the movable base and the subject or surface plate.

FIG. 5 is a cross-sectional view showing an embodiment of the present invention in which a wafer and a measurement contact are brought into contact with each other by utilizing the pressure of fluid.

FIG. 6 is a cross-sectional view of an example in which a measuring contact is supported by a supporting film having flexibility and elasticity.

FIG. 7 is a sectional view of an example in which a thin film contact having flexibility or elasticity is used instead of the measurement contact.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Surface plate 11 Buffer part 2 Wafer 12 Empty 3 Electrode to be measured 13 Vent hole 4 Contact block 14 Seal 4A Base 15 Supporting film 5 Measuring contact 16 Thin film contact 6 Backside round 17 Displacement sensor 7 Circuit board 18 Eccentric cam 8 Connection Means 19 Motor 9 Connector A Moving part 10 Moving base

Claims (8)

[Claims] 1. A measurement associated with an apparatus for performing characteristic inspection, measurement, or aging of a plurality of integrated circuit devices grown on a wafer or an object cut into pellets containing the plurality of integrated circuit devices. At the electrode
For the purpose of making highly accurate and reliable contact with the measured electrode part related to the subject, by adopting a structure in which a buffer part having elasticity and flexibility is interposed between the movable base and the contact block. A measuring electrode for an integrated circuit device wafer, characterized in that the contact block or the measuring contact can follow the surface condition of the object to be inspected and makes precise contact with the object. 2. The measuring electrode for an integrated circuit element wafer according to claim 1, wherein the measuring electrode including the electrode block is manufactured by an integrated circuit manufacturing technique. 3. A driver circuit and an interface circuit for performing measurement and aging of an object are mounted on a board portion including a printed circuit board and the like related to the connection of the conductor wire assembled from the plurality of measurement electrodes and the device. A measuring electrode for an integrated circuit device wafer according to claim 1. 4. The measuring electrode for an integrated circuit element wafer according to claim 1, wherein the contact block and the circuit board are connected by a flexible printed board. 5. The distance between the movable base and the object or surface plate is measured for the purpose of contacting the electrode to be measured with high accuracy and reliability, and control of the mutual gap and parallelism between them. A measuring electrode for an integrated circuit device wafer according to claim 1, wherein the measuring electrode is configured to be capable of fine adjustment. 6. The structure according to claim 1, wherein each measuring contact is configured to be pressed by the pressure of an elastic body or a fluid so as to improve copying with the surface of the subject. Measuring electrode for integrated circuit device wafer 7. For the purpose of making contact with the electrode to be measured with high accuracy and reliability, pressure from a fluid is applied from the back of the movable base or contact block, thereby contacting or contacting the subject. The measuring electrode for an integrated circuit element wafer according to claim 1, characterized in that the pressure is adjusted. 8. An apparatus configured to make contact with a subject and adjust contact pressure by the pressure of the fluid, by considering the structure of the contact block or the measurement contact, the passage of the fluid, etc. The measuring electrode for an integrated circuit element wafer according to claim 2, wherein the measuring timing and the contact pressure of the contact block and the measuring contact can be controlled.