JPS61171145A - Inspecting method for semiconductor device - Google Patents

Abstract

PURPOSE:To contrive accurate inspection by a method wherein the gap between the stage on which a semiconductor wafer is mounted and a probe of the probe card and the thickness of the semiconductor wafer are measured each and so controlled as to keep the proper amount of over drive. CONSTITUTION:Before a semiconductor wafer 4 containing a plurality of semiconductor devices 3 is mounted on a stage 1, the gap d1 between the stage 1 and the probe tip of the probe card 2 is measured. Next, the semiconductor wafer 4 is mounted on the stage 1, and the electrical capacitance between an electrical capacitance sensor 7 and a stage 1' is measured by an electrical capacitance measurement unit 8; then, the thickness d2 of the wafer 4 is measured from the variation in electrical capacitance. After the difference (d1-d2) is obtained by an operating unit 9 and probes 5 are fitted to the electrode pads of a semiconductor device 3 by moving the wafer 4 down the probe card 2, the stage 1 is raised by operating a drive unit 10 by an amount corresponding to the difference obtained by the operating unit 9, so that the probes of the probe card 2 may come into contact with electrode pads under a suitable pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for testing semiconductor devices, and particularly to a method for testing semiconductor devices on a semiconductor wafer.

[Conventional technology]

Conventionally, devices used to test semiconductor devices on a semiconductor wafer are called a characteristic testing device and a wafer prober. There are devices that place semiconductor wafers on a stage and transport them intermittently. Further, an inspection probe group (probe card) is attached to the urchin probe as a means for contacting the characteristic inspection device with the electrode t4 of the semiconductor device on the wafer. The globe card has probes fixed on a substrate in accordance with each electrode notch of the semiconductor device, and is replaced for each type of test product. Inspection of semiconductor devices is carried out by placing the wafer on a stage and touching the electrodes of the semiconductor device.
After aligning the probes of the globe and card with the tubes and raising the stage to make contact between the probes and the electrodes and rads, a characteristic inspection device was used to conduct an inspection. On the other hand, in order to keep the contact resistance between the probe and the electrode/head below a certain value, the needle pressure of the probe to the electrode/head is increased. The amount of rise of the stage after contacting the electrode/IP is called the overdrive amount, and by keeping this value constant, the contact resistance between the probe and the electrode/IP can be maintained at a constant value. We do the following to ensure that the inspection is error-free. This overdrive amount setting is achieved by making the long hands of a pair of probes called nip sensors contact the wafer and being lifted upward as the stage rises, while the other short hand remains in the same position. This method is set by taking advantage of the distance between the short hand and the short hand, and by keeping the rise of the stage constant after the electrical continuity between the long hand and the short hand is lost, or by visual inspection. There is a method of setting by confirming the height of the stage and keeping the rise of the stage constant from that point, or by passing the probe through the electrode pad of the semiconductor device.
A method has been used in which the specific resistance between the semiconductor wafer substrate and the stage is measured, and the rise of the stage from the point where the resistance suddenly decreases is kept constant.

[Problem that the invention seeks to solve]

The conventional overdrive setting method described above has the following problems. First, the edge sensor method uses the springiness of the probe, so there are problems with deterioration and variations in the springiness, and the visual method has problems with accuracy, and the way from the tip to the tip. The method of measuring the resistance up to the stage through the wafer is to set the overdrive amount using a substitute wafer, if there is a wafer whose resistance value is so high that it cannot be measured due to impurities being diffused to the back side by the wafer. Even with this method, there was a problem that it was not possible to maintain a constant amount of overdrive due to variations between the two.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and to provide a method for testing a semiconductor device that allows accurate testing by maintaining the correct amount of overdrive.

[Means for solving problems]

The present invention measures the distance between the stage on which the semiconductor wafer is placed and the tip of the probe card, and the thickness of the semiconductor wafer, calculates the difference between the distance and thickness, and uses the value of the difference. , a semiconductor device testing method characterized in that the semiconductor device is tested after adjusting the stylus pressure of a glove card to the electrode node of the semiconductor device.

〔Example〕

Examples of the present invention will be described below.

FIG. 1 is a schematic diagram of one embodiment of the invention.

Upper rainbow lobe of stage 1 of wafer groper
Card 2 is fixed. Before placing the semiconductor wafer 4 containing a plurality of semiconductor devices 3 on the stage, the distance d1 between the stage and the tip of the glove card is measured. In this example, the measurement method is to measure the electrical resistance between the probe 5 of the globe card and the stage using the measurement unit 6, and when the stage rises and comes into contact with the probe of the pronib card, the electrical resistance is measured. A decrease in the resistance value is detected, and the interval d1 is measured from the rise of the stage at that point.

As another example, there is also a method of measuring the distance d1 optically (using reflection of laser light, etc.). Next, the semiconductor wafer is placed on the stage, and the capacitance between the capacitance sensor 7 and the stage 1' is measured by the capacitance measurement section 8, and it is confirmed that the capacitance changes depending on the thickness d2 of the semiconductor wafer. Using this method, the thickness d of a semiconductor wafer can be measured from the capacitance.

Distance d1 between the probe and stage of these probe cards
The calculation unit 9 calculates the difference (
d1d2). After moving the semiconductor probe under the probe card and aligning the probe with the electrode pad of the semiconductor device, the amount (usually d, -d2+ ( The stage drive unit 10 is operated by 70 to 100 μ→ to raise the stage so that the probe of the probe card comes into contact with the electrode pad of the semiconductor device with appropriate needle pressure.

Thereafter, the semiconductor device is tested by the characteristic testing device 11 through the probe of the probe card.

[Effects of invention]

As explained above, the present invention calculates the difference (dl-d2) by determining the distance d1 between the probe of the probe card and the stage of the wafer prober and the thickness d2 of the semiconductor wafer. By keeping the amount of rise of the stage at a value corresponding to the value of d2), the pressure of the probe of the glove card against the electrode pad of the semiconductor device can be kept constant.

The contact resistance value between the probe and the electrode pad can be kept below a certain value, allowing accurate inspection. Also, the distance d1゜thickness dl
Both methods are electrically or optically measured, so they are more accurate than visual inspection methods, and because they do not use the springiness of the probe like nip sensors, there is little variation in measurement. Unlike the method of measuring the electrical resistance between the semiconductor wafer and the stage through the semiconductor wafer, the measurement is performed without passing through the semiconductor wafer, so it can be measured regardless of the electrical resistance of the semiconductor wafer, ignoring variations between semiconductor wafers. It has the effect that it can.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention. DESCRIPTION OF SYMBOLS 1... Stage of wafer prober, 2... Probe card, 3... Semiconductor device, 4... Semiconductor wafer, 5... Tip of probe card, 6...
Resistance measuring unit, 7... Capacitance sensor, 8... Capacitance measuring unit, 9... Calculating unit, 10... Stage drive unit, 11... Characteristic inspection device, dl... Distance between probe card probe and wafer prober stage, a2 - Thickness of semiconductor wafer

Claims (1)

[Claims] (1) In a method for inspecting a semiconductor device on a semiconductor wafer including a plurality of semiconductor devices, the distance between the stage on which the semiconductor wafer is placed and the group of inspection probes and the thickness of the semiconductor wafer are measured, and the distance between the 1. A method for inspecting a semiconductor device, comprising: calculating the difference between the thickness and the thickness of the semiconductor device, and adjusting the needle pressure of an inspection probe to an electrode pad of the semiconductor device based on the value of the difference, and then inspecting the semiconductor device.