JPH0715919B2 - Semiconductor wafer prober device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a semiconductor wafer prober apparatus.

(Prior Art) A prober device such as a semiconductor wafer prober is disclosed in Japanese Patent Laid-Open No.
No. 35441 publication, a semiconductor chip formed on a semiconductor wafer mounted on a measurement stage is brought into contact with a probe card to measure various electrical performances, and a defective chip is marked with an ink by a marker such as an inker. A defective product mark is attached by the marking operation to attach.

Further, the normal tester or prober device has a function of counting the number of non-defective chips based on the inspection result. However, there is a case where ink is scattered and adheres to a chip which is judged as a non-defective product as a result of inking, or ink is not attached to a defective product as a result of inking.

In order to prevent such mistakes, conventionally, after wafer measurement is completed,
Magnifying the chip While the operator confirms with a magnifying glass, the number of uninked chips is counted with a manual counter and compared with the number of non-defective chips based on the test results of the tester and prober device I was trying to find a malfunction of the marking device such as.

(Problems to be Solved by the Invention) As described above, the counting of chips without ink adheres to the eyes of a skilled person who has acquired detection ability after a long practice period, and the ink adherence has to be counted. There was a demand for automation of the process of counting chips that have not been processed.

The present invention has been made to solve the above points,
By using an automatic process to count chips that do not have ink, it is possible to reduce the time required to detect a malfunction of the marker and prevent defective chips from being determined as defective due to the malfunction of the marker or ink dripping. (EN) A semiconductor wafer prober device capable of improving the reliability of a probe inspection process and preventing unnecessary trouble between processes without transmitting an incorrect number of non-defective products to a subsequent process. Is.

[Structure of Invention]

(Means for Solving Problems) The present invention is to electrically contact a semiconductor chip formed on a semiconductor wafer to perform an electrical inspection, and to mark a semiconductor chip determined to be defective based on the inspection result. In a semiconductor wafer prober apparatus for marking with an apparatus, a camera for capturing an image of the semiconductor wafer to which a mark is attached as a result of the electrical inspection, and the presence or absence of marking on the semiconductor wafer for each semiconductor chip based on image data output from the camera. A first calculating means for determining and storing the result, and a second map for creating and storing a wafer map of the good and bad semiconductor chips of the semiconductor wafer from the result of the electrical inspection.
The output of the first arithmetic means and the output of the first arithmetic means are compared with each other, and it is determined whether or not marking is performed according to the result of the electrical inspection. The present invention provides a semiconductor wafer prober device comprising a third arithmetic means for counting chips.

The marking device is an inker to which ink is attached, and it is preferable that the marked chip also includes a chip to which ink is mistakenly attached. Also,
It is preferable that the information stored in the first computing means is information in which the presence or absence of marking is a wafer map. Furthermore, when the count number of the non-defective product output from the third computing means and the count number of the non-defective product obtained from the wafer map stored in the second computing means do not match, the marking device malfunctions. It is preferable to further provide a means for judging that it has been done.

(Operation) Since the present invention is configured as described above, the standard data value based on the image data of the wafer to be judged before inking and the image data of the wafer to be judged after inking are compared for each chip. By doing so, it is possible to easily and automatically detect that there is no mark on the chip formed on the wafer, and count the number. By automating the non-defective item counting process, the non-defective item counting time can be shortened, and the reliability of the wafer prober process is improved.

Further, according to the prober device of the present invention, even when ink is scattered during the inking operation on the defective chip and the ink adheres to the good chip, the wafer inspection result and the ink on the chip By comparing the adhesion and the wafer map, it is possible to correct the erroneous determination resulting from the inking error.

Further, according to the probe device of the present invention, the malfunction of the marking device can be easily found by comparing the inspection result of the wafer and the ink adhesion to the chip.

(Example) Next, an example of a semiconductor wafer prober device of the present invention will be described with reference to the drawings.

The feature of this embodiment is that the mark of the ink (2) attached to the defective semiconductor chip (1a) found as a result of the inspection by the wafer prober and the mark of the ink (2b) scattered and attached due to the inking error. Imaged with an ITV camera (3), a chip (1b) with no ink
Is to count the number of.

The wafer prober first carries the cassette in the state where the wafer is stored in the wafer cassette into the cassette housing portion, takes out the wafers one by one from the housing portion, and conveys the wafer onto the measurement stage (4). After the transferred wafer (5) is aligned with the orientation flat or the like as a reference, the measurement stage automatically soft-rides the probe card from below and automatically starts the inspection.

Next, the electrical performances of a large number of chips formed on the wafer (5) are determined, and an inking operation is performed to attach the ink (2) to the defective product by using a marker such as an inker (6). There is. Further, after the measurement is completed, the probe card is moved away from above the wafer, and a TV camera (3) is set above the wafer for the non-defective item counting process.

In order to execute these automatic processes, it is necessary to perform the teaching operation prior to the continuous process. This operation
It is performed by the operator while confirming the pad position of the wafer (5) using the TV camera (3).

Next, the procedure of the automatic counting process will be described with reference to FIG. First, the wafer (5) whose electrical performance has been measured is accurately positioned and placed on the measurement stage (4). TV camera (3) facing the wafer (5)
Is placed. The light from the light source installed beside the TV camera (3) is condensed by the converging lens (8) and irradiated onto the wafer (5), and the reflected light is reflected by the TV camera (3) such as an ITV camera. An image is taken (Fig. 3 (b)). The image is then converted into an electrical signal (first
(A), the image output is stored in the memory (first
(B)).

Then, the image information of the wafer to be measured (5) stored in memory is compared with the image information (reference data) (FIG. 1 (C)) stored in advance in the unmarked chip before measurement. (FIG. 1 (D)).

In this comparison, chips formed on the wafer (5) are compared one by one, and all the chips are compared. The chip corresponding to the portion where the compared reference data and the image data of the wafer to be judged do not match (FIG. 1 (E)) is judged to be the ink-tipped chip (1a). On the other hand, the chip corresponding to the portion (FIG. 1 (F)) where the compared reference data and the image data of the wafer to be judged match is judged to be an uninked chip (1b). It is counted (FIG. 1 (G)).

Then, the counted number of chips (1b) to which the ink is not attached is displayed on the display for display (10) installed in the prober. Of course, a chip that matches the reference data is judged and displayed as a chip without a mark.

Here, in the wafer map created in the storage memory inside the prober device based on the inspection result during the measurement, which chip is a good inspection result product and which chip is a defective product are stored. Therefore, this wafer map and ITV camera (3)
If the map of the chip with the mark (normal inspection result is bad) and the chip without the mark (normal inspection result is good) recognized in the same, it can be judged that there was no marking mistake. it can.

As a result, it is not necessary for the operator to count the number of unmarked chips and collate them with the number of chips that are good as a result of the inspection, and a highly reliable wafer inspection can be performed.

In the above embodiment, an example of counting the number of chips in which ink is not described has been described, but due to the ink scattering due to the inking operation on the defective chip,
Even if the ink adheres to the non-defective chip, the characteristic of the chip pattern before the measurement (that is, before the marking) is stored in the memory in advance, so that the corresponding chip adhered by the scattered ink can be selectively determined. That is,
It is possible to correct an erroneous determination of a chip which is determined to have a mark even though it is determined to be a non-defective product by the inspection and ink is attached.

The accuracy of this erroneous determination correction is automated by approximating the accuracy of the erroneous determination correction by the operator by storing all the ink patterns for which the scattered ink is determined to be non-defective by the operator as pseudo ink patterns in the reference data. It is possible. The difference between the scattered ink and the normal mark ink has a large area, the predetermined shape is a large element, and the darkness is also a large element. A normal mark is generally that the above elements are relatively consistent. This can be easily determined by pattern recognition.

Further, in the above-mentioned embodiment, the chips to which the ink is not attached are counted, but it is also possible to count the chips to which the ink is attached. However, the ink is also attached to the chip that is not completely configured as a circuit at the edge of the wafer, but since the edge chip has a different configuration for each wafer, the edge where the ink is attached is different. Since the number of chips in each of the wafers also differs from wafer to wafer, counting the number of chips with ink does not show much effect.

(Effects of the Invention) According to the present invention as described above, the non-defective product counting time can be shortened by automating the operation of detecting and counting that a chip formed on a wafer has no mark. It has the effect of improving the reliability of the.

Further, according to the prober device of the present invention, even when ink is scattered during the inking operation on the defective chip and the ink adheres to the good chip, the wafer inspection result and the ink on the chip By comparing the adhesion with the adhesion, it is possible to provide the prober device capable of correcting the erroneous determination resulting from the inking error.

Further, it is possible to provide a prober device capable of finding a malfunction of the marking device by comparing the inspection result of the wafer and the adhesion of the ink to the chip.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining one embodiment of the present invention, FIG. 2 is a diagram of a wafer on which the chip of FIG. 1 is formed, and FIG. 3 is a diagram of the wafer prober of FIG. . 1a ... defective chip 1b ... chip without ink 2 ... ink, 3 ... TV camera 5 ... wafer, 6 ... inker 8 ... lens

Claims (4)

[Claims] 1. A semiconductor wafer prober device for electrically contacting a semiconductor chip formed on a semiconductor wafer to perform an electrical inspection, and marking a semiconductor chip determined to be defective based on the inspection result by a marking device. A camera for picking up the image of the semiconductor wafer to which a mark is attached as a result of the electrical inspection, and a first operation for judging and storing for each semiconductor chip the presence or absence of a marking on the semiconductor wafer from image data output from the camera Second means for creating and storing a wafer map of good and defective semiconductor chips of the semiconductor wafer from the result of the electrical inspection.
The output of the first arithmetic means and the output of the first arithmetic means are compared with each other, and it is determined whether or not marking is performed according to the result of the electrical inspection. A semiconductor wafer prober device comprising a third arithmetic means for counting chips. 2. The marking device according to claim 1, wherein the marking device is an inker for adhering ink, and the marked chip includes a chip to which ink is accidentally adhered. Semiconductor wafer prober equipment. 3. The semiconductor wafer according to claim 1 or 2, wherein the information stored in the first arithmetic means is information in which the presence or absence of marking is a wafer map. Prober device. 4. The marking device when the count number of non-defective products output from the third computing means and the count number of non-defective products obtained from the wafer map stored in the second computing means do not match. Claim 1 further comprising means for determining that the malfunction has occurred.
The prober apparatus according to any one of the items 1, 2, and 3.