JPH07169801A - Prober - Google Patents

Abstract

PURPOSE:To prevent bringing to an unstable state of contact resistance due to the abrasion of the front end section of a probe for a probe card for conducting the electric test of a semiconductor device, and to perform the electric test correctly. CONSTITUTION:A prober is composed of a stage 6 for loading a wafer 5, an XYZ axis motor 7 for driving the stage 6, a counter 9 counting the number of the contacts of the electrode group of a semiconductor device and a probe 4 for a probe card 3 and a control section 8 for controlling these stage 6, motor 7 and counter 9, and the quantities of overdrives among the electrode group of the semiconductor device and the front end of the probe for the probe card are corrected, thus making contact resistance stable, then allowing the carrying- out of a correct test.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a prober for inspecting the electrical characteristics of a semiconductor device built on a semiconductor substrate during the manufacturing process of the semiconductor device.

[0002]

2. Description of the Related Art Conventionally, a test board is used to connect a tester to a semiconductor device on a wafer when performing an electrical test on a plurality of semiconductor devices built on a semiconductor substrate (hereinafter referred to as a wafer). And a jig called a probe card was used.

Particularly in the probe card, the electrodes of the semiconductor device are usually as small as about 70 to 100 μm square, and in some cases, the probe is brought into contact with a very small electrode group of about 20 μm square,
It is used as a jig for conducting electrical tests on semiconductor devices. In this way, the probe tip of the probe card is brought into contact with the electrode portion of the semiconductor device, and an electrical test is performed when a predetermined contact resistance value is obtained.

[0004]

In the conventional prober described above, the electrode group of the semiconductor device on the wafer mounted on the stage of the prober and the probe of the probe card are aligned, and then the electrode of the semiconductor device and the probe are aligned. Match the height of the card with the probe. After that, in order to obtain contact with the electrode and the probe having a predetermined resistance value or less, the probe is pressed against the electrode by a certain height to make contact. Moreover, the contact marks on the electrodes must be made as small as possible. This pressing amount is called overdrive,
Generally, the overdrive amount is about 50 to 80 μm to make contact.

However, several hundreds to several thousands of semiconductor devices are formed on one wafer, and tens of thousands to several hundreds of thousands of semiconductor devices must be electrically tested in lot units. I have to. As a result, the probe tip wears significantly in the last contact state compared to the first contact state in the lot, and the contact resistance that was initially required cannot be obtained, and the electrical test of the semiconductor device can be performed correctly. There was a problem of disappearing.

[0006]

SUMMARY OF THE INVENTION A prober of the present invention provides a stage for mounting a wafer, an XYZ axis motor for driving the stage, a contact count of an electrode group of a semiconductor device and a probe of a probe card. It has a counter for counting and a control unit for controlling these.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view of a first embodiment of the present invention, and FIG. 2 is a flow chart thereof.

In FIG. 1 and FIG. 2, after the parameters are input (201), they are mounted on the stage 6 of the prober 10 (20
2) As the alignment of the wafer 5, after aligning the positional relationship of the probe 4 installed on the probe card 3, the semiconductor device on the wafer 5 and the probe 4 are aligned by the XYZ axis motor 7 (203).

Next, as the height of the wafer, the heights of the electrode group of the semiconductor device and the probe 4 are matched (204).
After that, the probe 4 is pressed against the electrode group in order to obtain a predetermined contact resistance value. Normally, the contact resistance is set to within 0.5Ω and the overdrive amount is set to 50 to 80 μm (205). The position of the electrode group and the probe 4 is confirmed again (206), and the electrical test of the semiconductor device on the wafer is performed by the tester 1.

When the number of electrical tests of the semiconductor device on the wafer reaches a predetermined number of times, the control section 8 of the prober 10 is set so that the overdrive amount is automatically increased by several μm. The number of contact between the electrode and the probe 4 is counted (207). For example, when the overdrive amount is set to 50 μm and the number of electrical tests of the semiconductor device reaches 10,000, the next semiconductor device automatically corrects the overdrive amount to 52 μm, which is 2 μm (208).

The correction value for this overdrive amount cannot be uniformly set. That is, as a factor that determines the appropriate value for correcting the amount of wear of the probe 4, the material of the probe 4 is tungsten, palladium, beryllium copper, etc., and the thickness of the probe 4 ranges from 10 μm to 50 μm in tip diameter. Therefore, it is necessary to set different correction values depending on the probe card 3 suitable for the type of semiconductor device.

Next, a second embodiment will be described with reference to the sectional view of FIG. 3 and the flow chart of FIG. 4, and only the parts different from the first embodiment will be described.

In the case of this embodiment, after the height of the wafer is adjusted, the probe height 12 between the tip of the probe 4 and the back surface 13 of the substrate of the probe card 3 is measured by the sensor 11 before the electrical test. (401). When the number of electrical tests of the semiconductor device reaches a predetermined number, the probe height 12 between the tip of the probe 4 and the back surface 13 of the substrate of the probe card 3 is read again by the sensor 11 (402), and only the amount of wear of the probe 4 is read. Is added to the overdrive amount as a correction value, and an appropriate overdrive amount can be added regardless of the material and shape of the probe 4.

When the probe height 12 from the back surface 13 of the substrate of the probe card 3 to the tip of the probe 4 is worn to within the specified value, the prober 10 is stopped to trace the probe 4 on the electrode. It is possible to prevent the occurrence of an abnormal state in advance, and there is an advantage that the electrical test of the semiconductor device can be stably performed.

[0016]

As described above, according to the present invention, the overdrive amount is corrected when the number of electrical tests of the semiconductor device reaches a predetermined number, so that the electrode portion of the semiconductor device and the probe card are corrected. The contact resistance with the tip of the probe can be kept stable, and the semiconductor device can be properly tested electrically.

[Brief description of drawings]

FIG. 1 is a sectional view of a first embodiment of the present invention.

FIG. 2 is a flowchart of the first embodiment.

FIG. 3 is a sectional view of a second embodiment of the present invention.

FIG. 4 is a flow chart of a second embodiment.

[Explanation of symbols]

 1 Tester 2 Test Board 3 Probe Card 4 Probe 5 Wafer 6 Stage 7 XYZ Axis Motor 8 Controller 9 Counter 10 Prober 11 Sensor 12 Probe Height 13 Substrate Backside

Claims (2)

[Claims] 1. A stage for mounting a wafer,
An XYZ axis motor for driving the stage, a counter for counting the number of contact between the electrode group of the semiconductor device and the probe of the probe card, and an overdrive of the probe for the electrode group when the preset number of contact is counted. A prober comprising a controller for correcting the amount. 2. The prober according to claim 1, wherein the height from the back surface of the probe card to the tip of the probe is read during the test of the semiconductor device, and the operation of the prober is stopped when the height exceeds a set value.