JPS6030147A - Semiconductor wafer - Google Patents

Abstract

PURPOSE:To improve the yield of IC pellets and the working ratio of a test system for a semiconductor wafer, and to reduce man-hours on operation by forming a conductive pattern having no relation to a circuit function around a bonding pad in an adjacently insulating manner. CONSTITUTION:Paterns 3 for detecting the displacement of a probe are formed around bonding pads 2 in an insulating manner by insulating patterns 6. When inspecting an IC pellet 1, probe groups for a probe card in a wafer test system are positioned on the bonding pads 2, and electrical characteristics are measured. When the probe is displaced, the flaw of the probe is generated outside the bonding pads. When the probe is displaced, the bonding pads 2 and the patterns 3 for detecting the displacement of the probe are brought to a conductive state. Resistance values among the bonding pads 2 and pads 4 for detecting the displacement of the probe are measured, and alarm signals are given when the pads 2 and the pads 4 are brought to a conductive state. Defectives can be detected by the displacement of the probe, and the yield of the IC pellet is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of the Invention] The present invention relates to a semiconductor wafer, and more particularly to a semiconductor wafer including a pellet region with a check pattern.

[Prior art]

There is semiconductor wafer inspection in the manufacturing process of semiconductor integrated circuits (hereinafter referred to as semiconductor IC), and the IC pellet area (hereinafter simply referred to as IC pellet) that becomes a single pellet when manufactured on a semiconductor wafer and later cut is We are sorting out whether the products are good or defective.

Inspection of semiconductor wafers is performed using a semiconductor wafer test system, which is composed of an IC tester and a wafer prober. wafer prober tiI
Place the tips of the probe card directly on the c-pellet's pounding pad! i? This is a device for connecting iK.

The IC tester measures the electrical characteristics of the IC pellet, and has measurement functions such as voltage applied voltage measurement, voltage applied current measurement, and current applied voltage measurement.

The wafer inspection process involves performing one-course alignment and seven-point alignment using a wafer prober.
Align the probe of the glove card with the C-bellet's pounding pad and send the start signal to the IC tester.

The IC tester receives the start signal and runs in kW,
Outputs good product/defective product signals and test end signal. The wafer prober performs all processing based on the good product and defective product signals, and recognizes the end of the test using the test end signal.

When the end of the test is recognized, a probe group of the probe card is attached to the fifth-order IC pellet and a start signal is sent to all IC testers.

In this manner, the tests on the IC pellets are executed one after another until the test on the semiconductor wafer is completed. Incidentally, the bonding pad that the probe of the probe card came into contact with during this wafer inspection process is left with a scratch as a mark. By the way, during this wafer inspection process, the tip of the probe shifts from the measurement point of the bonding pad (hereinafter referred to as "needle brushing"), and if the tip of the probe hits a part other than the bonding pad, it will damage that position. . However, as long as a portion of the probe is in contact with the bonding pad, there is no problem in measuring the electrical characteristics, so the measurement continues. However, an IC pellet with scratches other than the bonding pad due to needle misalignment is considered a defective product because even if the electrical characteristics are good, the reliability after assembly is reduced. Therefore, a problem arises when a large number of defective products are produced.

The cause of needle misalignment that occurs during wafer probing is that although wafer probers use all laser beams to perform fine alignment, it depends on the surface condition of the wafer, and the position detection point of the IC pellet If the surface condition is rough and the surface condition is misrecognized, needle misalignment occurs.

In addition, if the probe of the probe card is bent or the precision of the X-axis and Y-axis feeding mechanisms of the prober deteriorates, resulting in cumulative displacement, needle misalignment may also occur.

Conventional semiconductor wafer test systems do not have a function to detect all needle misalignments caused by the above-mentioned causes, and detection of needle misalignment relies on visual inspection by an operator. For this reason, conventional semiconductor wafer test systems, even though they are automated systems, had to be stopped to confirm normal operation. This work of detecting needle misalignment, when there is no needle misalignment, is a big loss in terms of system downtime and operator man-hours.

Another problem is that even if needle misalignment is discovered, good IC pellets between the time the needle misalignment occurs and is discovered often have scratches on areas other than the bonding pad due to the needle misalignment, resulting in defective products. There was a point.

The conventional example will be explained in more detail with reference to the drawings. FIG. 1 is a diagram showing a situation in which a needle misalignment occurs at one location with respect to a bonding pad in a conventional semiconductor wafer. In the figure, a large number of bonding pads 2 are formed in an array on the IC pellet l, and when the probe group of the glove card comes into contact with the bonding pads, five markings are added to the bonding pads.
However, on the upper left pounding pad, a scratch has occurred outside the pounding pad due to needle misalignment.

Usually, the area around the bonding pad is silicon oxide [(Si
02), so even if the needle misalignment occurs on the surface and the insulating film is scratched, it will not immediately affect the characteristics (If IC pellet 1 has good electrical characteristics, the test results will be It will be a good product.

However, since the IC pellet 1 has a needle misalignment at one location, it has no choice but to be judged as a defective product by visual inspection due to reliability problems after assembly, resulting in the above-mentioned problems.

[Purpose of the invention]

An object of the present invention is to provide a semiconductor wafer which can solve all of the above-mentioned problems, improve the yield of IC pellets, improve the operating rate of a semiconductor wafer test system, and reduce the number of work steps.

[Structure of the invention]

The semiconductor wafer of the present invention is composed of a bullet region in which a conductive pattern unrelated to the function of the semiconductor integrated circuit is provided around each bonding pad adjacent to and insulated from the conductive pattern.

[Explanation of Examples]

Next, five embodiments of the present invention will be described with reference to one drawing.

FIGS. 2 and 3 are pattern diagrams of main parts of a semiconductor wafer for explaining the present invention in detail.

In FIG. 2, numeral 2 denotes an IC pellet, 2 denotes a bonding pad, and 3 denotes a pattern for detecting needle deviation, which is provided around the bonding pad insulated by an insulating pattern 6. 4 is a needle misalignment detection pad.

When inspecting the IC pellet 1 with the above configuration,
The probes of the probe card of the wafer test system are placed over all the bonding pads to measure the electrical characteristics. When all the probes are on the predetermined bonding pads, normal measurements are taken and the probes are not detected. Since the needle does not come off the top of the pounding pad, no needle displacement occurs.

However, as shown in FIG. 2, if the probe on the upper left of the bonding pad is displaced, a scratch from the needle will occur outside the bonding pad as shown in the figure, and the IC pellet will be defective. However, since this IC pellet is provided with a pattern for detecting needle deviation, the probe stylus brings the bonding pad and the pattern for detecting needle deviation to a conductive state, making it possible to detect the occurrence of needle deviation.

FIG. 4 shows the case where all the probes are misaligned. Therefore, each bonding pad 2 and the pattern 3 for detecting needle misalignment are measured by an IC tester between each bonding pad 2 and between each bonding pad 2 and for detecting needle misalignment. Measure the resistance value between it and the pad 4, and if it is in a conductive state, the IC tester will output a signal.

The alarm means can be fully activated to notify five workers of needle misalignment.

FIG. 4 shows an I
It is an explanatory enlarged view of the principal part of an example of C pellet. In the figure, the bonding pad 2 and needle misalignment detection pattern 3
are insulated by an insulating pattern 6 such as a silicon oxide film. In addition, since the insulating pattern bordering all of these is formed narrowly, the two are easily brought into conduction by contact with the probe, and needle displacement can be easily detected.

Note that the pattern for detecting needle deviation may be applied to all pellets on the semiconductor wafer, or may be applied only to pellets at selected locations.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to detect defective products due to needle misalignment, which could not be detected with conventional IC testers, improving the yield of IC pellets, and improving the operating rate of the semiconductor Qua71 test system. It is possible to obtain a semiconductor wafer with improved performance and a reduction in the number of man-hours required for one worker.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the fc starvation caused by a conventional bonding pad of an IC pellet formed on a semiconductor wafer and needle misalignment, and FIGS. 2 and 3 are main parts of a semiconductor wafer for detailed explanation of the present invention. FIG. 4 is an enlarged view of the main part of the pattern according to an embodiment of the present invention. l...IC pellet, 2...Ponding pad, 3...Pattern for needle misalignment detection, 4
...Pad for needle misalignment detection, 5-...Needle wheel mark, 6...Insulation pattern. Bi Z example and a half 3 times + 4 countries

Claims (1)

[Claims] A semiconductor wafer comprising a pellet region in which a conductive pattern unrelated to the function of a semiconductor integrated circuit is provided around, adjacent to, and insulated from each bonding pad.