JPS63170933A - Wafer prober - Google Patents

Abstract

PURPOSE:To prevent the occurrence of an inspection error which is caused by the deterioration of the electrical contact with a pad by a method wherein, after the tip of a probe has been brought into contact with an abrasive and has been ground, the probe is brought into contact with an electric-conductive material so as to measure the contact resistance. CONSTITUTION:After all the chips on a water have been measured, a stage 1 is driven by means of a drive system 13 so that an abrasive 2 can be positioned directly under a probe 6; the abrasive 2 is raised by means of a drive system 12; the probe 5 is ground. After the probe 6 has been ground, the stage 1 is driven by means of the drive system 13; the probe 6 is brought into contact with an electricconductive material 3; the continuity of the probe 6 is tested; its contact resistance is measured; it is inspected whether the probe 6 has been ground surely. By this method, a high-quality probing operation can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a wafer prober that inspects integrated circuit elements (hereinafter referred to as chips) formed on a semiconductor wafer in a wafer state.

[Conventional technology]

A wafer check is performed by bringing a tip probe into contact with the electrodes (hereinafter referred to as pads) of one or more chips, and applying a bias Φ from the IC tester via the tip probe.
It supplies signals and checks the characteristics to determine whether the chip is good or bad. The above probing search is repeated to inspect all chips on Ueno 1. Normally, the material of the tip probe is tungsten steel, and the material of the pad is mainly aluminum, so the material of the tip probe is harder than the material of the pad, so the tip probe sinks into the pad during blowing. As a result, the pad is damaged and the aluminum is slightly scraped, creating dust that adheres to the probe. If the number of times of blowing is large, the amount of dust attached will be large and the electrical contact with the pad will deteriorate, leading to inspection errors. Therefore,
The tip of the tip probe is usually polished to remove dirt attached to the probe.

[Problem that the invention seeks to solve]

The above polishing is automated. For example, wafer f: A ceramic member for polishing is mounted around the stage on which it is placed,
Set conditions, for example, for each waver, or for each
After blowing every 000 chips, the ceramic member is moved directly below the probe and moved up and down to repeatedly press it against the probe.

With conventional probers, only the above-mentioned automatic polishing is performed, and the dust on the tip of the probe is completely removed, and there is no way to check whether the contact resistance with the pad does not affect the measurement of the chip. .

[Means for solving problems]

The prober of the present invention has been made to solve the above problems, and includes a means for polishing the tip of the tip probe by bringing it into contact with a polishing member, and a means for bringing the polished tip probe into contact with a conductive member. and means for measuring resistance.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan view of the first embodiment, and FIGS. 2 and 3 are cross-sectional views thereof, which correspond to the probing state and the polishing◆contact resistance measurement (contact continuity test) state, respectively.

The Ueno 4 is attracted to the stage 1 by vacuum suction, and the stage 1 can freely rotate in the vertical and horizontal directions, in the perpendicular direction thereto, and in the tangential direction of the circumference of the stage 10. Each movement is driven by a drive system 13 and controlled by a control section 11.

Although the polishing member 2 and the 2N-type member 3 are fixed to the slider 1, they are movable independently in a direction perpendicular to the longitudinal and lateral movement plane of the stage l. This movement is driven by a drive system 12 and controlled by a control section 11. While the 'lifiM member 2 and the conductive member 3 are probing the wafer 4, their upper surfaces are located below the wafer chuck surface of the stage l, as shown in FIG. A ceramic material is used for the polishing member 2, and a substrate whose surface is coated with aluminum vapor deposition is used for the conductive member 3. The conductive member 3 is electrically insulated from the member to which it is attached. Also, the polishing member 2. When the conductive member 3 is driven, it rises from its original position as shown in FIG. 3, and its upper surface becomes the same as the surface of the wafer 4.

For a series of operations, first, a control instruction is given to the control unit 11 in advance. In other words, when one wafer has been measured, the tip probe 6 is polished, and after the polishing is finished, a contact continuity test is performed, and if the result of the contact continuity test is good, the next wafer is measured, and the contact continuity test is performed. It is an indication when to stop if the result is bad. In addition, as shown in the signal transmission path diagram in Figure 4, the tester 14 that operates together with the prober is configured to prepare and execute a test program for the continuity test when it receives a signal indicating the start of the contact continuity test from the prober. Give instructions in advance.

When a wafer is mounted on the prober using a wafer carrier or the like, the prober takes out the first wafer from the wafer carrier, supplies it onto stage l, and vacuum-chucks it. After collecting data such as the diameter and thickness of the wafer, wafer alignment is performed, and the tip probe 6t is brought into contact with the chip to start measurement. In the actual measurement procedure, as shown in FIG.
Reference numeral 4 sends a test signal to the tip probe 6 via the measurement system signal path 21 to measure the tip. Control unit 1 outputs a good product signal (bus signal) and a defective product signal (fail signal) according to the measurement results.
1, and then sends a signal (test end signal) indicating that the measurement has ended. This completes the measurement of one chip. Upon receiving the test end signal, the control section 11 drives the stage 1, brings the tip probe 6 into contact with the next chip, and sends a test start signal to the tester 14. This is repeated below.

When all the chips on the wafer have been measured, the polishing member 2 is positioned directly below the tip probe 6 as shown in FIG. Raise 2. Then, when the stage 1 is raised by the drive system 13, the tip probe 6 and the polishing member 2 come into contact and the tip probe 6 is polished.

When the polishing of the tip probe 6 is completed, the stage 1 is driven by the drive system 13 so that the conductive member 3 is positioned directly below the tip probe 6, and the drive system 12 further drives the conductive member 3 by the drive system 12.
to rise. Then, when the stage 1 is raised by the drive system 13, the probe 6 and the conductive member 2 come into contact with each other.

In this state, as shown in FIG.
A signal (probe test start signal) requesting the start of a continuity test is sent to the probe via the continuity test control signal path. The tester 14 receives the probe test start signal, sends a continuity test signal to the measurement system signal path 21, and measures the continuity state of the probe 6. According to the measurement results, a good product signal (probe test pass signal) and a defective product signal (probe test fail signal) are sent to the control unit 11, and then a signal indicating that the continuity test has been completed (probe test end signal) is sent. Contact resistance can be determined by measuring the continuity state by conducting a continuity test with.

Here, if the control unit 1 receives the probe test pass signal, the wafer on stage 1 is stored in the wafer carrier, the second wafer is mounted on stage 1, and the above operation is repeated. I'll return it. If the control unit 11 receives the probe test fail signal, the blow μ stops operating.

Next, a second embodiment will be explained with reference to FIG. FIG. 5 shows a schematic blow μ for explaining the outline of the operation.
FIG.

The stage 101 freely moves within the blowing plane of the blow μ. 121 represents the wafer supply position of the stage 101, and 122 represents the wafer storage position of the stage 101.

111.112 shows the flow of movement of the wafer 104. The wafer is conveyed by a belt from the wafer carrier 131 to the stage 101 or from the stage 101 to the wafer carrier 132.

The polishing member 102 and the conductive member 103 are independent from each other, and have substantially the same shape as a wafer. Polishing member 1
02 is a conveyance path 113, and the conductive member 103 is a conveyance path 114.
They are each supplied to the stage 101 and returned to their original positions after the work is completed.

The operation in FIG. 5 will be explained below. The conditions for instructing the blow μ are the same as in the first embodiment. When a wafer is loaded onto the blow μ by a wafer carrier, the blow μ
takes out the first wafer from the wafer carrier 131 and supplies it to the stage 101 through the transport path 111. After collecting data such as the diameter and thickness of the wafer, the wafer is aligned, and the tip probe 6 (
(not shown) to start the measurement. Tester 1
The signal communication between the stage 101 and the blow μ and the operation of the stage 101 when measuring the chip are also the same as in the first embodiment. When all chips have been measured, the wafer is transferred to the transport path 112'i
The wafer is then stored in the wafer carrier 132.

Next, the polishing member 102 passes through the conveyance path 113 and is vacuum-adsorbed onto the stage 101. The stage 101 moves directly below the tip probe 6, raises the stage 101, brings the polishing member 102 into contact with the tip probe 6, and performs polishing. When polishing is completed, the polishing member 102 is returned to its original position through the conveyance path 113. Subsequently, the conductive member 103 is supplied to the stage 101 through the conveyance path 114 and vacuum-adsorbed thereon. The stage 101 moves directly below the probe 6, raises the stage 101, brings the conductive member 103 into contact with the probe 6, and performs a continuity test.

The procedure for conducting the continuity test is the same as in the first embodiment.

When the continuity test is completed, the conductive member 103 is returned to its original position through the conveyance path 114.

If the result of the continuity test is good, the second wafer is supplied to the stage 101 through the transport path 111. Thereafter, the same procedure as above is repeated. Furthermore, if the continuity test is unsuccessful, the measurement is interrupted.

As explained above, in the present invention, immediately after polishing the tip probe, a continuity test is performed on the tip probe to measure the contact resistance, and it is verified that the tip probe has been reliably polished. This has the effect of realizing high quality blobbing.

[Brief explanation of the drawing]

FIG. 1 is a plan view of the wafer stage according to the first embodiment of the present invention, FIG. 2 is a cross-sectional view showing the state in which chip probing is to be performed, and FIG. FIG. 4 is a diagram showing the signal path between the tester and the prober, and FIG. 5 is a plan view of the second embodiment of the present invention. 1... Stage, 2... Polishing member, 3...
- Conductive member, 4... Wafer, 5... Probe guard, 6... Tip probe, 11... Control unit, 12, 13... Drive system, 14... Tester, 21
...Measurement system signal path, n...Tester/prober control signal path,...Continuity test control signal path, 101...Stage, 102...Polishing member, 103
... Conductive member, 104... Wafer, 111...
Conveyance path during wafer supply, 112... Conveyance path during wafer storage, 113... Conveyance path for polishing member, 114... Conveyance path for conductive member, 121... Wafer supply position, 122... - Wafer storage position, 131... Wafer supply carrier, 132... Wafer storage carrier.

Claims (1)

[Claims] A prober for checking the electrical characteristics of each chip formed on a semiconductor wafer includes a means for polishing the tip of a probe by bringing it into contact with a polishing member, and a means for bringing the polished tip of the probe into contact with a conductive member. A wafer prober comprising: means for measuring resistance.